From Other Journals By Journal Review Editors Past Editor: Scott M. Bradley, MD These are article reviews published in Pediatric Cardiology. The reviews are of articles published in pediatric and cardiology journals. |
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From Other Journals/Pediatric Cardiology Contents 2001 Issues: 2002 Issues:
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2001 Issues: From
Other Journals/Pediatric Cardiology 22.3 (May/June 2001) Lofland GK,
McCrindle BW, Williams WG, Blackstone EH, Tchervenkov CI, Sittiwangkul
R, Jonas RA, Congenital Heart Surgeons Society. Critical
aortic stenosis in the neonate: a multi-institutional study of
management, outcomes, and risk factors. J Thorac
Cardiovasc Surg 2001; 121:10-27. From 1994 to 2000, 320 neonates with critical aortic stenosis were entered into this prospective, multi-institutional study. Patient management was determined by the individual institutions. An initial Norwood procedure was used in 179 patients, with a 5-year survival of 60%. An initial biventricular repair was pursued in 116 patients (including a transcatheter balloon valvotomy in 83, and surgical aortic valvotomy in 28), with a 5-year survival of 70%. Separate multivariable hazard models for the 2 pathways were constructed and used to predict which of the 2 pathways would have resulted in better survival for each of the patients. Factors associated with better survival for a Norwood procedure compared to a biventricular repair were younger age, smaller size of the aorta at the sinuses of Valsalva, lower left ventricular length, higher grade of endocardial fibroelastosis, less severe tricuspid regurgitation, and larger size of the ascending aorta. Predicted survival benefit favored a Norwood procedure in 50% of the patients who actually underwent biventricular repair, and favored a biventricular repair in 20% of the patients who actually underwent a Norwood procedure. ¨ Several previous studies have examined risk factors for mortality in neonates with critical aortic stenosis. This study is notable for its large patient cohort, prospective approach, current treatment era, and inclusion of all variables examined in previous studies. It demonstrates that mortality remains high for critical aortic stenosis in neonates, and that many patients are assigned to a pathway which probably does not optimize their survival. The study is limited by the lack of information on other treatment pathways, such as cardiac transplantation, and the Ross procedure. The multivariable equation and calculator derived in this study are posted on the Web site of the CHSS and can be prospectively used to determine management in neonates with critical aortic stenosis. Shaddy RE,
Lambert LM, Fuller TC, Profaizer T, Thompson DD, Baker SI, Osborne KA,
Hawkins JA. Prospective
randomized trial of azathioprine in cryopreserved valved allografts in
children. Ann Thorac
Surg 2001; 71:43-8. 20 children were prospectively randomized to receive either azathioprine, or no azathioprine after receiving a cryopreserved valved allograft in the pulmonary position. 12 other patients were approached for inclusion in the study, but refused enrollment. Seven of the 20 patients withdrew before completion of the study. Four patients in the azathioprine group withdrew: 1 due to perioperative death, 1 to avoid further blood draws, 1 due to bacteremia, and 1 due to clostridium difficile colitis. 3 patients in the control group withdrew: 1 due to perioperative death, 1 to avoid further blood draws, and 1 due to mediastinitis. Thus 13 patients completed the study, 6 azathioprine and 7 controls. Panel reactive antibodies 3 months after operation rose from 0% to 84% in azathioprine patients, and from 1% to 96% in control patients (no significant difference between the 2 groups). There were also no differences between the 2 groups in allograft stenosis or regurgitation measured by echocardiography 13-17 months after operation. ¨ The role of immunologic rejection in limiting the durability of cryopreserved allografts remains controversial. This study is unique because it examines the effects of azathioprine on humoral immune response and allograft function in children in a prospective, randomized fashion. The small number of patients to complete the protocol underscores the many difficulties of pursuing such a study. The study bears out previous studies by this and other groups demonstrating a significant humoral immune response in the majority of children receiving cryopreserved allografts. The authors found that azathioprine had no important effect on this immune response, nor on allograft function. This leaves open the question of whether other, more potent immunosuppression drugs would be more effective, although it seems likely that their side effects would outweigh their potential benefits. Mahle WT,
Spray TL, Gaynor W, Clark BJ III. Unexpected
death after reconstructive surgery for hypoplastic left heart syndrome. Ann Thorac
Surg 2001; 71:61-65. The incidence of unexpected death was determined retrospectively among 536 patients with hypoplastic left heart syndrome who were discharged from the hospital after stage I surgery (Norwood procedure). These patients’ operations spanned a 15-year period, from 1984 to 1999. Unexpected death (defined as cardiovascular collapse from which the subject did not regain consciousness) occurred in 22 of 536 patients (4.1%). In addition, “nonoperative deaths” occurred in 63 of 536 patients (11.8%). The median age at unexpected death was 79 days (range 25-227 days); the median time from discharge to death was 40 days (range 1-208 days). Autopsy in 12 patients identified residual lesions in 2 patients, shunt narrowing in one and aortic coarctation in the other. Multivariable analysis showed that perioperative arrhythmia and earlier year of operation were associated with unexpected death. ¨ Interstage, nonoperative mortality has been observed in all series of staged surgical palliation for hypoplastic left heart syndrome. Most such deaths occur following discharge after Norwood procedure and prior to second stage, superior cavopulmonary connection. This retrospective study documents the incidence of unexpected death in a large series over a 15-year period. Possible causes of such mortality may include aortic arch obstruction, shunt thrombosis, arrhythmias, neurodevelopmental impairment with feeding difficulties and aspiration, and impaired coronary perfusion with ventricular dysfunction. However, in the majority of cases the specific cause is unknown. There remains much room for further study of the causes of interstage mortality in patients with hypoplastic left heart syndrome. Schreiber C,
Eicken A, Vogt M, Gunther T, Wottke M, Thielman M, Paek SU, Meisner H,
Hess J, Lange R. Repair of
interrupted aortic arch: results after more than 20 years. Ann Thorac
Surg 2000; 70:1986-1900. Between 1975 and 1999, 94 patients underwent surgery for interrupted aortic arch. A single-stage operation was performed in 75 (80%), and two-stage in 19 (20%). Mean follow-up was 6.7 years (range 0.1-21 years). For the single-stage approach, early mortality was 12% and late mortality 20%. For the two-stage approach, early mortality was 37% and late mortality 26%. Only 9 of the 19 two-stage patients attained complete repair. Left ventricular outflow tract obstruction (defined as a ratio of the diameter of the outflow tract to the diameter of the descending aorta of 0.6 or less) was seen in 13% of patients and was a risk factor for overall mortality. Freedom from reoperation at 5 years was 67%, and at 10 years was 53%. Reintervention was most commonly for aortic arch obstruction, airway compression, and left ventricular outflow tract obstruction. ¨ This large series of infants with interrupted aortic arch supports the surgical approach of single-stage repair. Nonetheless, both mortality and late reintervention remain significant. In this series, left ventricular outflow tract obstruction was associated with both mortality and the need for reintervention. The exact degree of outflow tract obstruction which mandates surgical relief at the first operation, as well as the best surgical approach to such relief, remain open questions. Stamm C,
Friehs I, Mayer JE Jr., Zurakowski D, Triedman JK, Moran AM, Walsh EP,
Lock JE, Jonas RA, del Nido PJ. Long-term
results of the lateral tunnel Fontan operation. J Thorac
Cardiovasc Surg 2001; 121:28-41. From October 1987 to December 1991, 220 patients underwent an intra-atrial, lateral tunnel Fontan procedure at Children’s Hospital Boston. Median patient age was 3.9 years; 38 (17%) had undergone a prior bidirectional Glenn shunt; 140 (63%) of the Fontan procedures were fenestrated. Operative failure (death or Fontan takedown) was 6%; risk factors were higher pulmonary vascular resistance, pulmonary artery distortion, higher postoperative Fontan pressure, and a single right ventricle. 33 patients (15%) had pleural effusions lasting more than 2 weeks. Follow-up was available for 196 patients (94%) at a mean of 10.2 years. Freedom from failure (death or takedown) at 10 years was 87%; the only risk factor was previous coarctation repair. Freedom from new supraventricular tachyarrhythmia (SVT) at 10 years was 91%; risk factors for late SVT were a common atrioventricular valve or atrioventricular valve regurgitation, early postoperative supraventricular tachycardia, and preoperative bradyarrhythmia. Freedom from new bradyarrhythmia at 10 years was 79%; the most important risk factors were preoperative bradyarrhythmia and early postoperative bradyarrhythmia. Only 3 patients developed protein-losing enteropathy. ¨ The two most commonly used approaches to Fontan’s operation are currently the intra-atrial lateral tunnel, and the extracardiac conduit. This report provides important long-term information on a large group of patients who underwent a lateral tunnel Fontan procedure at a single institution. It demonstrates that this technical approach to the Fontan operation can result in good long-term survival with low incidences of failure and SVT. Sinus node dysfunction remains an important issue. It is of interest that baffle fenestration did not affect either early or late outcome in this group of patients. As with many congenital heart operations, the Fontan procedure constitutes a moving target. It is possible that more recent changes, such as routine staging with a prior superior cavopulmonary connection, might affect (?improve) results even further. Nonetheless, this report provides a good benchmark for comparison to other approaches, such as the extracardiac conduit Fontan. Ing FF, Fagan TE, Grifka RG, Clapp S, Nihill MR, Cocalis M, Perry J,
Mathewson J, Mullins CE. Reconstruction
of stenotic or occluded iliofemoral veins and inferior vena cava using
intravascular stents: Re-establishing access for future cardiac
catheterization and cardiac surgery.
J Am Coll Cardiol 2001;37:251-257. 24 patients (range 0.2 to 12 years) underwent stent reconstruction of stenotic or occluded iliofemoral veins (IFV) and inferior vena cava (IVC). 85 stents were placed in 22 IFV and 6 IVC; 15 vessels were severely stenotic and 3 were completely occluded. Occluded vessels required puncture through the thrombosed sites using a stiff wire or transseptal needle, followed by serial dilation and then stent implantation. Vessel diameter increased from 0.9 mm to 7.4 mm. Follow-up study of 15 stented vessels showed 13 (85%) were patent. · In recent years, there has been increased success in treating patients with complex congenital heart disease, sometimes requiring repeated cardiac catheterizations and surgeries. Because of the need for repeated vascular access, vessel occlusion (that may occur as a result of these procedures) can be a significant problem in managing these patients. This excellent study offers an important technique for reconstructing stenotic or occluded veins. I found the detailed description of the procedures (including specifics of equipment used, helpful tips, and multiple photographs) very helpful. Highly recommended for anyone who has encountered this problem in the cath lab or surgical suite. Ovadia M, Cooper RS, Parnell VA, Dicapua D, Vatsia SK, Vlay SC.
Transvenous pacemaker insertion ipsilateral to chronic subclavian
vein obstruction: An operative technique for children and adults.
PACE 2000;23:1585-1593. The authors describe an operative technique to provide ipsilateral access in chronic subclavian vein occlusion in 5 consecutive pediatric (4 children, age 3-9) and adult (one, age 70) patients in order to insert pacing electrodes. Indications for pacing were complete heart block in children and ventricular tachycardia in the adult. Percutaneous brachiocephalic or deep subclavian access was achieved by a supraclavicular approach. Electrodes were positioned in the heart and tunneled to a pre- or retropectoral pocket. Pacemaker and implantable cardioverter defibrillator (ICD) implants were successful in all, without complication. · The authors describe what appears to be a powerful new technique for patients with subclavian venous occlusion who require a pacemaker or ICD placement. Using this method may avoid use of the contralateral vein, so that the chance of bilateral obstruction is minimized. Because of increased problems with vessel occlusion in patients requiring multiple procedures (see previous article and comments), new approaches for addressing this challenge are welcome. Hernandez-Diaz S, Werler MM, Walker AM, Mitchell AA.
Folic acid antagonists during pregnancy and the risk of birth
defects. N Engl J Med
2000;343:1608-1614. Periconceptional use of multivitamins may reduce the risk of cardiovascular defects and other congenital malformations in offspring. In order to determine whether the folic acid component of multivitamins helps reduce these defects, the authors examined the associations between maternal use of folic acid antagonists, antiepileptic medications, and congenital malformations, using interviews with mothers of infants with malformations in 80 maternity or tertiary care hospitals, over a 24 year period. The exposure to these medications was assessed in 3870 infants with cardiovascular defects, 1962 with oral clefts, 1100 with urinary tract defects, and in 8387 controls (infants with malformations not influenced by vitamin supplementation). Among mothers exposed to the folic acid antagonists, the relative risk of cardiovascular defects was 3.4, while the risk of oral clefts was 2.6. Mothers exposed to antiepileptic medications had relative risks of 2.2 (cardiovascular defects), 2.5 (oral clefts), and 2.5 (urinary tract defects). Use of multivitamins containing folic acid diminished the adverse effects of folic acid antagonists, but not that of antiepileptic drugs. · This interesting, large study strongly suggests that maternal use of multiple vitamins containing folic acid may reduce the incidence of congenital heart disease in the offspring of these pregnancies. While I have sometimes joked with my adult cardiology colleagues that they could be put out of business with a few vitamin pills and lifestyle changes, it also appears that vitamins could also cut down on our patient population. This would obviously be beneficial for the children and families who would avoid echoes, surgeries, and catheterizations, but if the benefits of prevention become too widespread, we pediatric cardiologists might also face a diminished workload (you can decide for yourself if this would be good or bad for you). Fredriksen PM, Chen A, Veldtman G, Hechter S, Therrien J, Webb G.
Exercise capacity in adult patients with congenitally corrected
transposition of the great arteries.
Heart 2001;85:191-195. 41 adults with congenitally corrected transposition of the great arteries (CCTGA) had cardiopulmonary testing at rest and with exercise. Aerobic capacity (V02max) was diminished at 30-50% of that found in normal subjects. Although RV and LV ejection fractions (EF) were normal at rest, with exercise, the EF of the systemic RV only increased 2% (vs. > 5% in healthy subjects), while the EF decreased by 2% in the pulmonary LV. Other factors that may have contributed to decreased exercise capacity include blunted peak heart rate and systolic blood pressure with exercise, decreased forced expiratory volume in one second (FEV1), and decreased forced vital capacity. · Patients with CCTGA have increasing morbidity and mortality as they age; this study provides useful information why this is so. Van Overmeire B, Van de Broek H, Van Laer P, Weyler J, Vanhaesebrouck P.
Early versus late indomethacin treatment for patent ductus
arteriosus in premature infants with respiratory distress syndrome.
J Pediatr 2001;138:205-211. 127 premature infants (gestational age 26-31 weeks) with PDA were randomly assigned to receive early (day 3) or late (day 7) intravenous indomethacin. Although the PDA closure rate was higher in the early group at 6 days (73% vs. 44%) and 9 days of age (91% vs. 78%), there was no difference in subsequent need for PDA ligation. The early treatment group had lower urine output, higher serum creatinine, more indomethacin courses, and more major adverse events (death, necrotizing enterocolitis, extension of hemorrhage, cystic leukomalacia). · This large, prospective, multicenter trial appears to show minimal benefits and significant morbidity with early administration of indomethicin in premature neonates with a PDA. Although older studies suggested a benefit for early treatment, these were done prior to recent advances in care such as antenatal corticosteroids and early treatment with surfactant. Brembilla-Perrot B, Marçon F, Bosser G, Lucron H, Houriez P, Claudon O,
Holban I, Blangy H. Paroxysmal
tachycardia in children and teenagers with normal sinus rhythm and
without heart disease. PACE
2001;24:41-45. 31 children or adolescents (age 9-19) with normal ECG and suspected or documented episodes of supraventricular tachycardia (with palpitations and syncope) had esophageal programmed stimulation. Sustained tachycardia was induced in 27 patients, at rest in 13, and after isoproterenol in 14. AV nodal reentrant tachycardia was the cause in 22 of these. 6 patients had a vagal reaction and dizziness. · As the authors suggest, the diagnosis of supraventricular tachycardia could be underestimated in adolescents whose symptoms are dismissed because noninvasive studies are negative. If symptoms suggest possible supraventricular tachycardia, esophageal or traditional electrophysiology studies should probably be considered. |
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From
Other Journals/Pediatric Cardiology 22.4 (July/August 2001) Dilated
cardiomyopathy in isolated congenital complete atrioventricular block:
Early and long-term risk in children.
Udink ten Cate FEA, Breur JMPJ, Cohen MI, Boramanand N, Kapusta
L, Crosson JE, Brenner JI, Lubbers LJ, Friedman AH, Vetter VL, Meijboom
EJ. J Am Coll Cardiol 2001; 37:1129-1134. To identify the risk factors predicting development of dilated cardiomyopathy (DCM) in patients with isolated congenital complete atrioventricular block (CCAVB), 149 patients with CCAVB were retrospectively evaluated, with a mean follow-up of 10 years. 9 patients developed DCM at age 6.5 ± 5 years. 8/9 had pacemakers in the first month of life. In patients who developed DCM, the initial left ventricular end-diastolic dimension (LVEDD) was in the 96th percentile and the cardiothoracic (CT) ratio was 64%; this was significantly higher than patients who did not develop DCM. After initiating pacing, LVEDD and CT ratio decreased significantly in patients without DCM, but did not improve in patients with DCM. Among patients with DCM, two died, one is neurologically compromised, two had heart transplantation, and four are listed for heart transplantation. · Patients with CCAVB have traditionally been considered relatively benign, though patients eventually require pacemakers. This large, multicenter study suggests that a significant subset of these patients are at risk for developing DCM despite pacemaker placement, and such patients may require more intensive therapy. Cardiac output and central distribution of blood flow in the human
fetus. Mielke G,
Benda N. Circulation 2001; 103:1662-1668. To establish reference ranges for cardiac output and establish blood flow distribution in human fetuses, 222 normal fetuses underwent high-resolution echocardiograms. Right cardiac output was 59% and left cardiac output was 41% of biventricular output. Ductal blood flow was 46%, pulmonary flow 11%, and foramen ovale flow was 33% of biventricular output. · Although cardiac output and distribution of blood flow have been well-studied in fetal animals, only limited data are available for human fetuses. This excellent study clearly demonstrates right heart dominance in human fetuses. Interestingly, the estimated ratio of pulmonary blood flow to cardiac output is higher than in fetal lamb studies. This information will become particularly useful if fetal interventions are used in the future to improve the outcome for specific cardiac lesions. Delayed recognition of haemodynamically relevant congenital heart
disease. Pfammatter JP,
Stocker FP. Eur J Pediatr 2001; 160:231-234. To evaluate the proportion of children with delayed diagnosis, this prospective study examined 323 consecutive pediatric patients requiring surgical or catheter interventional treatment for congenital heart disease. 32 (10%) had delayed diagnosis; the proportion of delayed diagnosis was similar in patients with cyanotic and acyanotic lesions. 7 of the 32 patients had complications due to delayed referral, but there was no mortality associated with late diagnosis. · Although most children with congenital heart disease are diagnosed relatively promptly, this study shows a significant number of patients with significant heart defects had delayed diagnosis. One interesting finding of this study was that all patients with late diagnosis had clinical cardiac findings other than systolic murmurs (increased precordial pulsation, fixed split S2, cyanosis, etc.) that should have alerted the physician to the possible presence of underlying heart disease. Do patients over 40 years of age benefit from surgical closure of atrial
septal defects? Jemielity
M, Dyszkiewicz W, Paluszkiewicz L, Perek B, Buczkowski P, Ponizynski A.
Heart 2001; 85:300-303. 76 patients, age 40-62 years of age underwent surgical closure of atrial septal defect (ASD), with one operative and one late death. Pre-operatively, 47 (62%) were in NYHA functional classes III and IV; postoperatively, 61 (82%) were in classes I and II. Echocardiography showed RV site decreased from 4.1 to 2.9 cm. · Although some authors have found no differences in survival rates or symptoms in adults with ASD having surgery and those managed medically, in this relatively large group of patients, surgery was quite beneficial. These patients with large left-to-right shunts, might also be expected to benefit from trans-catheter closure. Although not emphasized by the authors, a key component of preoperative evaluation is measurement of pulmonary vascular resistance to rule out pulmonary vascular disease. This study also highlights the need for improved early diagnosis (see previous review). The Fontan procedure for tricuspid atresia: Early and late results of a
25-year experience with 216 patients.
Mair DD, Puga FJ, Danielson GK. J Am Coll Cardiol 2001;
37:933-939. 216 patients with tricuspid atresia had nonfenestrated Fontan procedure over a 25 year period. Overall survival was 79%; operative mortality declined and was 2% (1/58) in the most recent decade. Age at operation had no effect on operative mortality, and late mortality was only increased in patients operated on at age 18 or older. 89% of surviving patients are in NYHA class I or II. 3 patients died of thromboembolic complications; one had a stroke. Among the 167 surviving patients with follow-up, only 8 were receiving any form of anticoagulation therapy (warfarin, for mechanical mitral valve in 3 and for atrial arrhythmias in 5). The risk of protein-losing enteropathy was 13.4% after 10 years. The authors conclude that these results justify continued use of the nonfenestrated Fontan for children with tricuspid atresia. · This large study, with relatively long follow-up, shows excellent results of the non-fenestrated Fontan in patients with tricuspid atresia. Although several recent reports have advocated use of a fenestrated Fontan, there may still be a role for a non-fenestrated Fontan in tricuspid atresia. It may never happen, but a large, randomized trial could answer many questions that remain for the Fontan: 1.) to stage, or not to stage; 2.) to fenestrate or not to fenestrate; and 3.) to anticoagulate, or not to anticoagulate. Television watching, energy intake, and obesity in US children.
Crespo CJ, Smit E, Troiano RP, Bartlett SJ, Macera CA, Andersen
RE. Arch Pediatr Adolesc Med 2001; 155:360-365. Using a nationally representative survey with an in-person interview and a medical examination, data were collected on 4069 US children, ages 8 to 16 years of age, between 1988 and 1999. Obesity was lowest among children watching 0-1 hours of television per day, and highest among those watching 4 or more hours a day. Girls engaged in less physical activity per day than boys. The authors conclude that clinicians and public health interventionists should encourage active lifestyles in children. · While hardly surprising, the results of this study (when considered along with other reports showing increasing inactivity, obesity, and type II diabetes among youth) are certainly alarming. One would suspect that television viewing and inactivity among children, already at high levels in the years studied, may be even more common today. We should all do our part to combat this growing epidemic (or perhaps encourage it to provide plenty of future patients for our adult cardiology colleagues). Long-term
results of relief of subaortic stenosis in univentricular
atrioventricular connection with discordant ventriculoarterial
connections. Jahangari M,
Shinebourne EA, Ross DB, Anderson RH, Lincoln C. Ann Thorac
Surg 2001; 71:907-10. Between 1985 and 1998, 24 patients with univentricular atrioventricular connection to a dominant left ventricle and discordant ventriculoarterial connections underwent enlargement of ventricular septal defects for subaortic stenosis. The median age at surgery was 3.2 years (range 3 weeks to 14 years). Median preoperative subaortic gradient was 46 mmHg. Operative mortality was 5/24 patients (21%). 10 year survival was 60%. Risk factors for mortality were age less than 1 year at operation, and the presence of obstruction in the aortic arch. Complete heart block occurred in 2 patients (8%). Recurrent obstruction occurred in the first 2 patients of the series; subsequently patch enlargement of the rudimentary right ventricle was routinely added to the operation, with no further recurrences. At a median follow-up of 6.7 years (8 months to 13 years), 10 patients had undergone a Fontan operation, 5 a bidirectional Glenn shunt, and 2 cardiac transplantation. ¨ Subaortic stenosis is a well-recognized complication in patients with univentricular atrioventricular connection to a dominant left ventricle and discordant ventriculoarterial connections. Subaortic stenosis can cause ventricular hypertrophy, which is a risk factor for a subsequent Fontan operation. One approach to this problem is surgical enlargement of the ventricular septal defect, which constitutes the subaortic outflow tract. This paper provides information on the long-term results of this approach, which are notable for good relief of obstruction, when combined with patch enlargement of the rudimentary right ventricle, and a low incidence of heart block. These results should be compared to those of the alternative Damus-Kaye-Stansel, or Norwood approach, particularly in patients under 1 year of age with aortic arch obstruction. Open commissurotomy for critical isolated aortic stenosis in neonates. Alexiou C,
Langley SM, Dalrymple-Hay MJR, Salmon AP, Keeton BR, Haw MP, Monro JL. Ann Thorac
Surg 2001; 71:489-93. 25 consecutive neonates underwent open valvotomy for critical aortic stenosis between 1984 and 2000. The operative approach included cardiopulmonary bypass, cardioplegic myocardial arrest, and valvotomy under direct vision. 7 of the 25 patients (2 of whom died early) had hypoplastic left ventricles or associated cardiac defects, and were excluded from further analysis. Among the 18 remaining patients with isolated aortic stenosis, there was no operative mortality. At discharge, the mean aortic valve gradient was 37 mmHg; 6 patients had mild, and 2 moderate aortic insufficiency. At a mean follow-up of 8 years, 6 patients required reoperation, 3 of these a mechanical aortic valve replacement (at 9-11 years of age). 10 year freedom from aortic valve replacement was 79%, and from aortic reoperation or reintervention 55%. The mean valve gradient at last follow-up was 36 mmHg; 6 patients had mild, and 5 moderate aortic insufficiency. ¨ This report serves as a reminder that open surgical valvotomy can give good results in neonates with isolated critical aortic stenosis. These results compare favorably with those of either percutaneous balloon valvotomy, or the Ross-Konno procedure. This approach, which includes circulatory support with cardiopulmonary bypass, may be particularly useful in the occasional patient who cannot be stabilized using prostaglandins and inotropes. Survival after reconstructive surgery for hypoplastic left heart syndrome; a 15-year experience form a single institution. Mahle WT,
Spray TL, Wernovsky G, Gaynor JW, Clark BJ III. Circulation
2000; 102:III-136-III-141. This paper reviews the long-term survival of patients undergoing reconstructive surgery for hypoplastic left heart syndrome at The Children’s Hospital of Philadelphia from 1984-1999. During this period, 840 patients underwent stage I (Norwood) surgery. Overall 10 and 15 year survival was 39%. Only 1 patient died beyond 5 years of age; only 5 patients underwent cardiac transplantation after initial surgical palliation. Later era of stage I surgery, age < 14 days and weight > 2.5 Kg at stage I were associated with significantly better survival. ¨ Over the 15 year course of this review, the early- and intermediate-term survival for patients undergoing staged surgical palliation for hypoplastic left heart syndrome improved significantly. Among patients discharged to home after a Fontan procedure, subsequent death and cardiac transplantation were notably uncommon. This review provides an interesting look at a period of dramatic advances in the pre-, intra-, and postoperative management of patients with hypoplastic left heart syndrome. Ministernotomy versus full sternotomy in congenital heart defects; a prospective randomized study. Luo W, Chang
C, Chen S. Ann Thorac
Surg 2001; 71:473-5. 100 patients undergoing repair of an atrial septal defect (34 patients) or ventricular septal defect (66 patients) were prospectively randomized to receive a lower ministernotomy, or a full sternotomy. The ministernotomy approach included a 6-12 cm skin incision and division of the lower sternum. All operations were performed by a single surgeon. The mean patient age was 10 years. The ministernotomy group had significantly longer procedure times (from skin to skin), and shorter mean hospital stays (6.5 vs. 7.5 days, p = 0.02). There was no difference in myocardial ischemic time, cardiopulmonary bypass time, intubation time, ICU stay, or blood transfusions. ¨ This study is notable for the facts that it was prospectively randomized, and that all the operations were by a single surgeon. It verifies that it is difficult to show any substantive difference between a ministernotomy and a full sternotomy approach in children undergoing congenital heart operations. While the ministernotomy group had shorter hospital stays, the difference was small, and hospital stay is quite variable from unit to unit. Nonetheless, as long as the ministernotomy approach provides equal safety and effectiveness, but preferable cosmesis, its appeal (particularly to patients and parents) is apparent. Developmental and neurologic effects of alpha-stat versus pH-stat strategies for deep hypothermic cardiopulmonary bypass in infants. Bellinger
DC, Wypij D, du Plessis AJ, Rappaport LA, Riviello J, Jonas RA,
Newburger JW. J Thorac
Cardiovasc Surg 2001; 121:374-83. Patients undergoing reparative cardiac operations at less than 9 months of age using deep hypothermic cardiopulmonary bypass (with or without circulatory arrest) were enrolled in this single-center trial. The patients were prospectively randomized to the use of alpha-stat versus pH-stat strategy for pH management during cardiopulmonary bypass. This report provides information on the developmental and neurologic outcomes at 1, and 2 to 4 years of age. Such information was available in 153 patients. The Psychomotor Development Index scores of the alpha-stat and pH-stat groups did not differ (P = 0.97). The Mental Development Index score of the pH-stat group was slightly higher for patients with transposition of the great arteries and tetralogy of Fallot, although the difference was not statistically significant. In contrast, the Mental Development Index score of the pH-stat group was significantly lower for patients with ventricular septal defect. There were no significant differences between the alpha-stat and pH-stat groups in abnormalities on neurologic or electroencephalographic examination at 1 year, or in parents’ rating of the children’s development or behavior at 2 to 4 years. ¨ During cardiopulmonary bypass, arterial pH and PCO2 may be managed by one of two strategies, alpha-stat (in which PCO2 is maintained at 40 mm Hg measured at 37oC and not corrected for the patient’s temperature), and pH-stat (in which PCO2 is adjusted to 40 mm Hg corrected to the patient’s temperature). In adults, neurologic outcomes appear to be better with the alpha-stat strategy. In infants, several nonrandomized, retrospective reports suggest that neurologic outcomes may be better with the pH-stat strategy. The current study is the only randomized clinical trial of pH strategy in a pediatric population. In a previous report examining perioperative outcome in this cohort, the pH-stat strategy was associated with trends toward fewer deaths, fewer electroencephalographic seizures, shorter recovery time to first electroencephalographic activity, and (in patients with transposition) shorter duration of intubation and ICU stay (du Plessis et al. Perioperative effects of alpha-stat versus pH-stat strategies for deep hypothermic cardiopulmonary bypass in infants. J Thorac Cardiovasc Surg 1997; 114:991-1001). The current report examines neurodevelopmental outcome at 1 to 4 years in the same patient cohort. The use of alpha-stat versus pH-stat management was not consistently related to either improved or impaired neurodevelopmental outcomes. Given the large size, study design, and sophisticated neurodevelopmental follow-up, this study provides the most convincing answer to date on this controversy. |
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From Other Journal /
Pediatric Cardiology 22.5 (September/October 2001) Prêtre R, Tamisier D, Bonhoeffer P, Maurlat P, Pouard, P, Sidi D, Vouhé
P. Results of the arterial
switch operation in neonates with transposed great arteries. Lancet 2001; 357:1826-1830. 432 neonates underwent an arterial switch operation over a 13-year period. The probability of survival at 10 years was 94%, and freedom from reoperation was 78% at 10 years. 26 patients died, 16 because of ischemia. Risk factors for death were early experience, low weight, associated cardiac malformations such as right ventricular hypoplasia or aortic arch hypoplasia, and difficult coronary artery patterns. Coronary artery pattern was less of a risk factor in recent years. At most recent evaluation, 90% had normal lives without treatment, and 94% had normal function on echocardiogram. · In this large series of unselected patients, excellent mid-term results are reported. As the authors point out, coronary artery obstruction is the cause of most deaths and a substantial number of reoperations; attention should be focused on this area in these patients. It appears likely that the long-term prognosis will be equally encouraging for patients undergoing arterial switch. Schmidt B, Davis P, Moddemann D, Ohlsson A, Roberts RS, Saigal S,
Solimano A, Vincer M, Wright LL. Long-term
effects of indomethacin prophylaxis in extremely-low-birth-weight
infants. N Engl J Med 2001;
344:1966-1972. Soon after birth, 1202 infants with birth weights of 500 to 999 g were randomized to receive indomethacin or placebo once daily for 3 days. Among infants receiving indomethacin, 47% died or survived with impairments, compared to 46% in those receiving placebo. Patients receiving indomethacin had lower incidence of patent ductus arteriosus (24% vs 50% in placebo) and of severe periventricular and intraventricular hemorrhage (9% vs 13% in placebo). The authors conclude that in extremely-low-birth-weight infants, prophylaxis with indomethacin reduces the incidence of patent ductus arteriosus and severe periventricular and intraventricular hemorrhage, though it does not improve the rate of survival without neurosensory impairment at 18 months. · This large, multicenter trial clearly shows that prophylactic indomethacin reduces the incidence of patent ductus arteriosus and intracranial hemorrhage in extremely-low-birth-weight infants. Unfortunately, this did not lead to better survival without neurologic damage, so that recommendations for using routine indomethacin prophylaxis do not appear to be unequivocal. Mahle WT, Clancy RR, McGaurn SP, Goin JE, Clark BJ.
Impact of prenatal diagnosis on survival and early neurologic
morbidity in neonates with the hypoplastic left heart syndrome.
Pediatrics 2001; 107:1277-1282. To determine if prenatal diagnosis reduces neurologic morbidity and operative mortality in patients who have palliative surgery for hypoplastic left heart syndrome (HLHS), data from 216 patients with HLHS were reviewed, including all patients with HLHS (but no lethal genetic anomaly) from a single institution over a five-year period. 37% had been diagnosed prenatally. Overall hospital mortality was 26% and was similar in patients diagnosed prenatally and postnatally. Using multivariate analysis, prenatal diagnosis of HLHS was associated with fewer adverse neurologic events than postnatal diagnosis (15% vs 26%). · It is interesting that several studies, including this one, have failed to demonstrate a survival benefit for patients with HLHS diagnosed prenatally. However, significantly improved neurologic outcome in prenatally diagnosed patients suggests that prenatal diagnosis of HLHS may be beneficial, likely by reducing the risk of preoperative hypoxia and ischemia. Simpson JM, Moore P, Teitel DF. Cardiac
catheterization of low birth weight infants.
Am J Cardiol 2001; 87:1372-1377. 111 catheterizations were performed in 107 infants weighing less than 2.5 kg over 14 years at a tertiary-referral center. 31 procedures were interventional, including 16 with balloon atrial septostomy, 10 with collateral vessels in 3, all performed successfully. One infant died while undergoing myocardial biopsy. The reintervention rate for isolated pulmonary valve stenosis gradually increased to 71% (5 of 7) at one year. Complications were more frequent in interventional (42%) than in diagnostic (16%) procedures. The most common complications during interventions were arrhythmias (10%) and respiratory deterioration (10%). The authors recommend that low birth weight infants should have elective intubation for interventional cardiac catheterization. · In recent years, many centers have had increasing numbers of small patients requiring catheterization and intervention. Despite this trend, limited data are available regarding the risks and complications in this group of patients. This fine study provides useful information for anyone performing such studies. McElhinney DB, Clark BJ III, Weinberg PM, Kenton ML, McDonald-McGinn D,
Driscoll DA, Zackai EH, Goldmuntz E.
Association of chromosome 22q11 deletion with isolated anomalies
of aortic arch laterality and branching.
J Am Coll Cardiol 2001; 37:2114-2119. To determine the frequency of chromosome 22q11 deletions in patients with isolated anomalies of the aortic arch and its branches, 66 such patients were studied, including 22 with double aortic arch, 28 with right aortic arch and aberrant left subclavius artery; and others with various other isolated anomalies. 16 (24%) had 22q11 deletions, across the full spectrum of anomalies studied. · As suggested by the authors, these findings should alert the clinician to consider deletion screening in patients with isolated anomalies of the aortic arch. Pediatric
heart transplantation: improving results in high-risk patients. J Thorac
Cardiovasc Surg 2001; 121:782-91 73 pediatric patients underwent heart transplantation between 1990 and 1999. An additional 22 of a total of 116 patients listed for transplant (19%) died on the waiting list. A cardioplegic solution containing blood and added insulin (vs. crystalloid-based cardioplegia) for the donor heart was introduced in 1997 and used in the 37 patients transplanted subsequently. 11 patients (10 of whom were ≤1.2 years of age) underwent intentional transplantation with ABO-incompatible hearts, with 2 early and 1 late death. 13 patients required preoperative support with ECMO, with 3 early and 3 late deaths. Mean donor ischemic time was 255 minutes (range 51-610 minutes). Hospital mortality among the 73 patients transplanted was 14%. Survival at 5 years was 73%. Risk factors for death were ECMO (P = 0.05), and use of crystalloid donor cardioplegia (P = 0.08), but not ABO incompatibility or donor ischemic time. ¨ This study focuses on a number of unconventional strategies designed to increase the donor pool for pediatric heart transplantation. It demonstrates that ECMO can be used successfully as a bridge to transplant, although these patients remain at higher overall risk. Donor hearts with ischemic times up to 10 hours can also be successfully used. The interesting possibility of transplanting infants across ABO compatibility is documented. Fraser
CD, McKenzie ED, Cooley DA. Tetralogy of
Fallot: surgical management individualized to the patient. Ann Thorac
Surg 2001; 71:1556-63. In the management protocol followed in this report, patients requiring surgery at less than (roughly) 4 kg or 6 months of age underwent initial modified Blalock-Taussig shunt, followed by complete repair at 6-12 months of age. All other patients underwent complete repair after 6 months of age. From 1995 to 1999, 144 patients were operated for tetralogy of Fallot (129) or tetralogy of Fallot with atrioventricular septal defect (15). 94 patients had one stage complete repair, 39 had repair after initial shunt, and 10 await repair after shunt. The mean age at complete repair was 18 months. There were no operative, and 3 late deaths. There were no instances of surgical heart block. 4/133 patients (3%) have required reoperation after complete repair. ¨ This report serves as a reminder that a selective two stage approach to tetralogy of Fallot can give excellent results. The authors point out that by avoiding complete repair in small patients, this approach avoids the use of circulatory arrest, and minimizes the use of a ventriculotomy for VSD closure (transatrial, transpulmonary repair). Such a selective approach to complete repair of tetralogy may be preferred even in centers (such as this one) which are well-equipped to perform complete cardiac repairs in neonates. Bacha
EA, Almodovar M, Wessel DL, Zurakowski D, Mayer JE Jr., Jonas RA, del
Nido PJ. Surgery for coarctation of the aorta in infants weighing less than 2 kg. Ann Thorac Surg 2001; 71:1260-4. 18 consecutive patients less than 2 kg underwent repair of aortic coarctation between 1990 and 1999. Median weight was 1330 gm (range 800 - 1950 gm). 15 were ductal-dependent, but none were operated emergently. All were repaired via left thoracotomy by resection and end-to-end anastomosis; 2 had additional reverse subclavian flap augmentation of the distal aortic arch. There were 1 hospital and 2 late deaths. 8 patients (44%) had residual or recurrent coarctation; 5 underwent balloon dilation and 3 reoperation. Risk factors for mortality were Shone’s syndrome or a hypoplastic aortic arch. The only risk factor for recoarctation was weight < 1.5 kg. ¨ Aortic coarctation can be repaired in low-birth weight neonates, by standard techniques, with low risk. Recoarctation is common, but can also be managed at low risk. This report suggests that early repair will be preferable to delay in small neonates with coarctation. It also provides a good standard for comparison to the results of primary balloon dilation in such patients.
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Laudito A,
Brook MM, Suleman S, Bleiweis MS, Thompson LD, Hanley FL, Reddy VM. The Ross
procedure in children and young adults: a word of caution. J Thorac
Cardiovasc Surg 2001; 122:147-53 72 patients underwent a Ross or Ross-Konno procedure between 1993 and 2000. Their median age was 9.1 years, with 81% being less than 15 years old. The indication for operation was aortic insufficiency (isolated or predominant) in 27 and aortic stenosis in 45. 12 patients had “autograft failure”, defined as either reoperation for severe autograft insufficiency (7 patients) or the development of at least moderate autograft insufficiency (5 patients). All 12 patients developed autograft failure more than one year postoperatively. Among a variety of variables examined as predictors for autograft failure, only aortic insufficiency (isolated or predominant) as an indication for operation was a statistically significant risk factor. ¨ This study verifies an important incidence of failure after the Ross procedure, due to dilation of the autograft at the level of the annulus, the sinuses of Valsalva, and the sinotubular junction. It is also one of several which indicate that preoperative aortic insufficiency, and/or aortic annular dilation, is a risk factor for such autograft failure. It leaves open the question of whether technical modifications of the Ross procedure, such as external reinforcement of the annulus and sinotubular junction, can decrease, or avoid such failures. Huddleston
CB, Balzer DT, Mendeloff EN. Repair of
anomalous left main coronary artery arising from the pulmonary artery in
infants: long-term impact on the mitral valve. Ann Thorac
Surg 2001; 71:1985-9. From 1980-2000, 16 patients less than 18 months of age underwent repair by reimplantation of the left coronary into the ascending aorta. 9 patients had moderate or severe mitral regurgitation preoperatively. Only one of these underwent concomitant mitral valve repair. There was one operative, and no late deaths at a mean follow-up of 6.9 years. 2 patients developed moderate or severe mitral regurgitation during follow-up. Both had initial improvement in regurgitation postoperatively, but then worsened over time. Both were found to have obstruction of the reimplanted left coronary, and were treated by mitral valve repair and left coronary revascularization 2 and 6 years after initial operation. ¨ This series confirms the excellent results now achieved by direct reimplantation of the anomalous left coronary artery into the aorta. It also makes the interesting, and new observation that mitral insufficiency which worsens over follow-up suggests accompanying obstruction of the reimplanted left coronary. Hutter PA,
Thomeer BJM, Jansen P, Hitchcock JF, Faber JAJ, Meijboom EJ, Bennink
GBWE. Fate of the
aortic root after arterial switch operation. Eur J
Cardio-thorac Surg 2001; 20:82-88 The diameter of the aortic root was followed by echocardiography in 144 patients who had undergone an arterial switch operation. 97 had transposition with an intact ventricular septum; 47 had an associated VSD. 21 underwent pulmonary artery banding prior to switch. Median follow-up was 8.6 years and ranged from 0.1-22 years. Following switch, the aorta at the level of the annulus had a mean Z-score of 1.5, which did not change significantly over time. The sinuses of Valsalva had a mean Z-score of 1.4, which also did not change significantly over time. The sinotubular junction (site of aortic anastomosis) had a mean Z-score which reached 0.8 at 4 months, and then showed little subsequent change. Patients with a VSD had an aortic annulus Z-score 0.75 larger than those without a VSD. Patients with preliminary pulmonary artery banding had similar aortic annulus and sinotubular junction sizes, but larger sinuses (by 2.8 Z-scores) than those without banding. No patient developed aortic stenosis. Only 5/144 (3.5%) had grade 2 or more aortic insufficiency. ¨ This report contains a great deal of detailed information on the size and function of the neo-aortic root after the arterial switch operation. Following arterial switch, the neo-aortic root at the level of the annulus, sinuses, and sinotubular junction is larger than normal. Over time, the aortic root increases in proportion to patient size, implying normal growth. Aortic root dilation in and of itself is rarely associated with significant aortic insufficiency. Mahle WT,
Gaynor JW, Spray TL. Atrioventricular
valve replacement in patients with a single ventricle. Ann Thorac
Surg 2001; 72:182-6. From 1984-2000, 17 patients with single ventricles underwent atrioventricular valve replacement at the Children’s Hospital of Philadelphia. The median age at replacement was 3 years, with a range of 7 days - 17 years. Hospital mortality was 29%, with the last death occurring in 1993. The new onset of complete heart block was 44%. Age less than 2 years was a risk factor for operative mortality, and no patient less than 2 years old survived more than 6 months after operation. In late follow-up there were 4 deaths and 1 heart transplant. Among 7 late survivors, there were no reports of thromboembolism, bleeding, or valve re-replacement. ¨ Atrioventricular valve replacement in patients with single ventricles is rare, as evidenced by the fact that the 17 patients in this report constitute only 1% of those undergoing single ventricle operations over the time of the study. This paper is the largest single review of this topic to date. As with most operations, results have improved over time. However, there remain significant risks of morbidity, and late mortality. Some risk may relate to the difficulties in accurately assessing ventricular function in the face of atrioventricular valve regurgitation. This paper also raises the possibility that patients under 2 years of age might be better served by heart transplantation. Alexiou C,
McDonald A, Langley SM, Dalrymple-Hay MJR, Haw MP, Monro JL. Aortic valve
replacement in children: are mechanical prostheses a good option? Eur J
Cardio-thorac Surg 2000; 17:125-33 56 patients ranging in age from 1 to 16 years underwent aortic valve replacement with a mechanical prosthesis between 1972 and 1999. Half of the patients underwent concomitant aortic root enlargement by division of the annulus into the anterior leaflet of the mitral valve (Nicks procedure). The mean size of the implanted valves was 22 mm (range 17 - 27). All patients were anticoagulated with coumadin, aiming for an INR of 2.5 - 3.0. Follow-up was for a mean of 7 years, a range of 0 - 26 years, and a total of 405 patient-years. Operative mortality was 3/56 (5%). There were 3 late deaths; actuarial survival at 20 years was 85%. Thromboembolism occurred at a rate of 0.3% / patient-year, with an actuarial freedom of 93% at 20 years. There was no incidence of bleeding requiring transfusion, nor any incidence of prosthetic valve endocarditis. Five patients require reoperation, none due to outgrowth of the valve. Actuarial freedom from reoperation at 20 years was 86%. ¨ This report details the results of a long series of mechanical aortic valve replacements in children. The low rates of thromboembolism and bleeding are notable, although this data was retrospectively acquired. The liberal use of aortic root enlargement likely contributed to the low rate of reoperations. This series provides a good comparison to the results of homografts or autografts (Ross procedure) for aortic valve replacement in children. Alexiou C,
Galogavrou M, Chen Q, McDonald A, Salmon AP, Keeton BK, Haw MP, Monro JL. Mitral valve
replacement with mechanical prostheses in children: improved operative
risk and survival. Eur J
Cardio-thorac Surg 2001; 20:125-113 44 patients ranging in age from 2 months to 16 years underwent mitral valve replacement with a mechanical prosthesis between 1981 and 2000. 23 patients were less than 5 years old, 9 were less than 1 year old. Indication for operation was mitral regurgitation in 36 and mitral stenosis in 8. The mean size of the implanted valves was 24 mm (range 16 - 31). All patients were anticoagulated with coumadin, aiming for an INR of 3.0 - 3.5. Follow-up was for a mean of 6 years, a range of 0 - 18 years, and a total of 213 patient-years. Operative mortality was 6/44 (14%), but declined to 3.6% after 1990. There were 4 late deaths; actuarial survival at 10 years was 78%. Thromboembolism occurred at a rate of 0.9% / patient-year, with an actuarial freedom of 93% at 10 years. Bleeding occurred at a rate of 0.9% / patient-year, with an actuarial freedom of 98% at 10 years. Prosthetic valve endocarditis occurred at a rate of 0.9% / patient-year, with an actuarial freedom of 97% at 10 years. Eight patients required reoperation related to the mitral valve. Actuarial freedom from reoperation related to the mitral valve at 10 years was 75%. ¨ This report details the results of a current series of mechanical mitral valve replacements in children. Mortality has declined in the last decade, and the rates of complications are quite low. This series provides an interesting comparison to the previously reviewed paper from the same group on mechanical aortic valve replacements, and that of Mahle et al on atrioventricular valve replacement in patients with single ventricles.
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2002 Issues:
Ringewald JM,
Gidding SS, Crawford SE, Backer CL, Mavroudis C, Pahl E.
Nonadherence is associated with late rejection in pediatric heart
transplant recipients. J
Pediatr 2001; 139:75-78. To study the impact of
nonadherence on late rejection after pediatric heart transplantation,
the records of 50 patients surviving longer than 6 months were reviewed.
In 15 patients with 49 episodes of late rejection, 37 (76%) were
associated with nonadherence. 7
of the 15 patients died, and 3 of 15 had coronary artery disease.
Risk factors for rejection were single parent home, non-white,
older age, and higher cyclosporin A level variability (indicating
nonadherence). The authors
conclude that late rejection after pediatric heart transplantation
associated with nonadherence is common during adolescence, and is
associated with poor outcome. ·
Clearly, social issues are critical in
patients being evaluated for and receiving cardiac transplantation.
This nice study emphasizes the importance of this, and provides
useful information not only for transplant programs but also for
pediatric cardiologists considering referral for transplantation. Miller, MD, Porter
CJ, Ackerman MJ. Diagnostic
accuracy of screening electrocardiograms in long QT syndrome I.
Pediatrics 2001; 108:8-12. To evaluate the efficacy
of the automated ECG as a screening tool for inherited long QT syndrome
(LQTS), the authors used molecular testing of a proband and 22 family
members to evaluate the KVLQTI mutation and symptomatic status.
13 were non-carriers, 5 were asymptomatic carriers, and 5 were
symptomatic carriers. All
had standard ECGs. Corrected
QT interval (CQTI) was determined by computer and manually, and the
accuracy of the computer ECG diagnostic interpretation was assessed.
Using a CQTI of
460 ms as a diagnostic cutoff, the positive and negative predictive
values for identifying at-risk individuals was 100%.
However, 6 of 23 family members were erroneously classified by
computer-derived ECG interpretation.
Further, half of the family members with a proven ion channel
defect received a computer interpretation of "normal ECG."
The authors recommend that all first-degree relatives of a LQTS
proband have a 12-lead ECG that is reviewed by a physician familiar with
LQTS. ·
As the authors emphasize, reliance on
computer-generated ECG diagnostic interpretation alone will fail to
identify many at-risk family members.
I always appreciate studies that suggest I will have future job
security; however, at some point I suspect the computer programmers
might succeed in improving automated computer interpretation of ECGs.
When that happens, the role of the pediatric cardiologist may
become less important. Until
then, it appears we (pediatric cardiologists) are still needed for
optimal ECG interpretation. Amer-Wåhlin I,
Hellsten C, Norén H, Hagberg H, Herbst A, Kjellmer I, Lilja H, Lindoff
C, Månsson M, Mårtensson L, Olofsson P, Sundström AK, Marsál K.
Cardiotocography only versus cardiotocography plus ST analysis of
fetal electrocardiogram for intrapartum fetal monitoring: a Swedish
randomized controlled trial. Lancet
2001; 358:534-538. 4966 women with term
fetuses entered this randomized trial during labor, after a clinical
decision was made to apply a fetal scalp electrode for internal
cardiotocography. They were
randomly assigned monitoring with cardiotocography alone (CTG group) or
cardiotocography plus ST analysis (CTG + ST group).
The CTG + ST group showed significantly lower rates of umbilical
artery metabolic acidosis than the CTG group (0.7% vs. 2%), and of
operative delivery for fetal distress (8% vs. 9%).
Differences were greater after exclusion of patients with
malformations or inadequate recording. ·
I found this large study very interesting
and potentially beneficial for perinatal management.
I suspect that some of the neonatal ECGs I interpret show unusual
ST-T segments because of the perinatal stress described in this paper. Videlefsky N, Parks
WJ, Oshinski J, 33 patients (age 0.4 to
19.5 years) underwent magnetic resonance (MR) phase-shift velocity
mapping of pulmonary venous (PV) pathways; results were compared with
cardiac catheterization and Doppler echo data. MR imaging showed precise
anatomical detail of the pulmonary veins in 7 patients with PV
obstruction and 26 without obstruction.
Patients with obstruction had phase velocities of 100 to 250
cm/s, while controls had velocities of 20 to 71 cm/s; these results were
similar to Doppler findings. MR
velocity mapping was 100% specific and 100% sensitive in detecting PV
obstruction. In the absence
of left-to-right shunt lesions, PV velocities of 100 cm/s and greater
indicated significant obstruction. ·
In my opinion, one of the best uses for
MRI is exploration of lesions that are sometimes difficult to evaluate
by echocardiography, such as pulmonary venous malformations or
obstruction. This fine study
shows the usefulness of this powerful modality in evaluating such
patients. Ahmad F, Kavey REW,
Kveselis DA, Gaum WE, Smith FC. Responses
of non-obese white children to treadmill exercise.
J Pediatr 2001; 139:284-290. A retrospective review
of treadmill exercise studies on 347 white American children aged 5 to
18 years was performed with metabolic criteria to verify maximal
exercise effort. Exercise
endurance time was lower in all age groups when compared with earlier
published data. The maximum
systolic and diastolic BP increased with increasing age.
The authors conclude that lower exercise endurance times are seen
despite physiologic evidence of maximal effort, and they suggest that
cardiovascular conditioning may be reduced in contemporary American
children. ·
The gradual deconditioning of American
youth is a trend I have noted with alarm over the past several years.
This study provides objective evidence of the poor level of
fitness in a population of non-obese white children.
An important challenge is how best to respond to this important
and emerging problem. |
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March/April
2002 issue [23.2] Cao QL, Du ZD,
Joseph A, Koenig P, Heitschmidt M, Rhodes J, Hijazi ZM.
Immediate and six-month results of the profile of the Amplatzer
septal occluder as assessed by transesophageal echocardiography.
Am J Cardiol 2001; 88: 754-759. The Amplatzer septal occluder (ASO) has shown promise in closing secundum atrial septal defects (ASDs), though there are concerns about the large profile of the device after closure. To assess changes in profile of the device, the authors performed transesophageal echocardiography in 70 patients immediately after catheter closure of ASD by ASO, and at 6-month follow-up. Median size of ASD was 14 mm (range 3 to 25); median size of device was 19 mm (range 8 to 34). Complete closure was seen in 81% initially, and in 91% at 6-month follow-up. Device thickness decreased by 42 to 48% over 6 months, from 12.2-12.5 mm to 6.3-6.5 mm. · Although the ASO appears to be quite effective in ASD closure in the short-term, long-term results are not yet available. This excellent study provides valuable information, showing that one concern in use of this device, its high profile, appears to improve after initial deployment. Channick RN,
Simmoneau G, Sitbon O, Robbins IM, Frost A, Tapson VF, Badesch DB, Roux
S, Rainsio M, Bodin F, Rubin LJ. Effects
of the dual endothelin-receptor antagonist bosentan in patients with
pulmonary hypertension: A randomised placebo-controlled study. Endothelin I, an endogenous vasoconstrictor and mitogen, appears to play an important role in pulmonary hypertension (PHT). Patients with severe PHT have elevated levels of endothelin. This study was undertaken in order to evaluate the efficacy and safety of bosentan, a dual endothelin-receptor antagonist that can be taken orally, in patients with severe PHT. 32 patients with PHT (primary or associated with scleroderma) were randomly assigned to bosentan or placebo for at least 12 weeks. Patients receiving bosentan had significantly improved exercise capacity (6 minute walk distance increased by 70 meters vs. decreasing by 6 meters in controls), higher cardiac index (1.0 l/min/m2 greater than controls), and decreased pulmonary vascular resistance (PVR decreased by 223 dyn s cm–5 vs. increasing by 191 dyn s cm-5 in controls). · Bosentan, an antagonist of both endothelin subtypes (ETA and ETB) has been studied in rats with chronic pulmonary hypertension, and was found to reduce pulmonary arterial pressure, pulmonary vascular hypertrophy, and right ventricular hypertrophy, without inducing systemic vasodilation. This intriguing, randomized, placebo-controlled trial suggests that bosentan may also prove useful for short- and long-term treatment of humans with PHT. Treatment of patients with PHT is often challenging, and while primary PHT in children is quite rare, secondary PHT (e.g., from congenital heart disease or from cardiomyopathy), which was not addressed in this study, is more common. Until now, treatment modalities have been limited and either invasive or not very effective (heart-lung transplant, intravenous continuous prostacyclin, or traditional medical support). I look forward to further studies to clarify the role of this apparently powerful substance for treatment of PHT. Jenkins PC, Flanagan MF, Sargent JD, Canter CE, Chinnock RE, Jenkins KJ, Vincent RN, O'Connor GT, Tosteson ANA. A comparison of treatment strategies for hypoplastic left heart syndrome using decision analysis. J Am Coll Cardiol 2001; 38:1181-1187. Decision analysis is a modeling technique that structures a problem into choices, chance events, and outcome measures. It is used to provide a framework for quantitatively identifying the treatment strategy that, on average, has the highest chance of success. This technique was used to compare six strategies used to treat hypoplastic left heart syndrome (HLHS): staged surgery, transplant (Tx), stage 1 surgery as an interim to Tx, and listing for transplant for 1, 2, or 3 months before performing staged surgery if a donor is unavailable. Probabilities were derived from the literature and a dataset of 231 patients with HLHS born between 1989 and 1994. Using this technique, the authors found that if a donor is available within one month, Tx is the optimal choice; if no donor is found by that time, stage 1 surgery should be performed. Centers with organ donation rates less than 10% in 3 months and with stage 1 mortality less than 20% should have staged surgery. If the 3-month organ donation rate is greater than 30%, waiting one month on the transplant list would optimize survival. · As the treatment for HLHS has evolved in recent years, various strategies have been proposed to improve treatment of this challenging group of patients. The novel technique of decision analysis offers an interesting perspective which may help pediatric cardiologists make the best treatment decisions for patients with HLHS. Häusler M, Hübner
D, Delhaas T, Mühler EG. Long
term complications of vena cava thrombosis.
Arch Dis Child 2001; 85: 228-233. A combined retrospective and prospective study on infants and children with inferior vena cava (IVC) thrombosis was performed, to evaluate outcomes in such patients. 40 patients were included, including 4 who had cardiac catheterization, 18 with central venous saphenous lines, and 8 with umbilical venous catheters. 6 died within 3 months of diagnosis, and one was lost to follow-up. Among the 33 surviving patients, 12 had limited IVC thrombosis, none of whom showed persisting caval obstruction. Among the 21 with extensive IVC thrombosis, caval flow was only established in 4 (one thrombolysis, 2 surgery, one spontaneous revascul |
