Mohinder K. Thapar

Causes of recoarctation after balloon angioplasty of unoperated aortic coarctation

During the 35 month period ending December 1987, 30 children, aged 14 days to 13 years, underwent balloon angioplasty of unoperated aortic coarctation with resultant reduction in coarctation gradient from 43.6 +/- 20.4 to 9.5 +/- 7.6 mm Hg (p less than 0.001). None of the patients required immediate surgical intervention. On the basis of results of 6 to 30 month follow-up catheterization data in 20 children, the patients were classified as follows: Group A, 13 patients with good results (gradient less than or equal to 20 mm Hg and no recoarctation on angiograms) and Group B, 7 patients with fair or poor results (gradient greater than 21 mm Hg with or without recoarctation on angiography). No patient developed aortic aneurysm at the site of angioplasty. Thirty variables were examined by multivariate logistic regression analysis and four factors were identified as risk factors for development of recoarctation: 1) age less than 12 months, 2) aortic isthmus less than 2/3 the size of the ascending aorta immediately proximal to the right innominate artery, 3) coarcted aortic segment less than 3.5 mm before dilation, and 4) coarcted aortic segment less than 6 mm after angioplasty. The identification of risk factors may help in selection of patients for balloon angioplasty. Avoiding or minimizing the number of risk factors may help reduce the chance of recoarctation after angioplasty. The intermediate-term follow-up results with regard to recoarctation are comparable with those after surgical repair of coarctation. Recoarctation after angioplasty was dealt with by repeat balloon angioplasty or surgical resection for those requiring treatment and clinical follow-up for the remaining children.(ABSTRACT TRUNCATED AT 250 WORDS)

Balloon angioplasty for coarctation of the aorta: Immediate and long-term results

Twenty-five infants and children with native coarctation of the aorta had percutaneous balloon angioplasty over a 28-month period ending in May, 1987. The mean systolic pressure gradient across the coarctation decreased from 47.6 +/- 20.9 mm Hg to 10.3 +/- 7.3 mm Hg (p less than 0.001) following angioplasty, and the diameter of the coarcted segment increased from 3.2 +/- 1.7 mm to 7.8 +/- 3.5 mm (p less than 0.001). Clinical and echo-Doppler follow-up indicated excellent results in 16 of the 18 patients in whom 3- to 22-month follow-up was available; two infants required additional treatment (repeat angioplasty in one and surgical resection in the other). Fourteen patients who underwent repeat cardiac catheterization remain improved with regard to pressure gradient across the dilated coarctation (9.5 +/- 9.6 mm Hg, p less than 0.001) and angiographically measured sizes of the coarcted segment (10.3 +/- 3.2 mm, p less than 0.001). No aneurysm was seen in any child. We recommend balloon angioplasty as the therapeutic procedure of choice for relief of severe, previously unoperated coarctation of the aorta in neonates and young infants. Routine use of balloon angioplasty for unoperated coarctation of the aorta in children appears indicated, but should await longer follow-up results and reports of follow-up on a larger number of patients; this caution is mainly based on reports from other workers of aneurysm formation at the site of balloon dilatation.

The Initial Attack of Acute Rheumatic Fever During Childhood in North India A Prospective Study of the Clinical Profile

A prospective study was done to determine the clinical profile of first attacks of acute rheumatic fever in children in North India. Unlike other reports, the clinical profile described here closely resembles the spectrum prevalent in the West. Arthritis, the most common manifestation, was seen in 66.6% of the 102 patients, chorea in 20.7%, and carditis in 33.7%. Carditis was considered mild in 22 patients and severe in 12; a persistent elevation of sleeping pulse rate and mitral regurgitation was noted in each case. Patients with severe carditis also had significant cardiomegaly and apical mid-diastolic murmur. Two patients with severe carditis developed congestive heart failure; one of them had pericarditis as well. Murmur of aortic origin was not noted in this series. One patient with severe carditis died from the disease. Erythema marginatum was noted in two, both of whom had severe carditis. There were two instances of subcutaneous nodules, one with and one without carditis. The close similarity of these results with those in the West is attributed to the prospective design of the study, analysis of first attacks only and survey of a general pediatric population for all manifestations suggestive of the disease.

Cardiac specialized tissue in hearts with an apparently single ventricular chamber (double inlet left ventricle).

Abstract The morphologic and histologie findings in 14 univerrtricular hearts are described. All hearts had a single ventricle with a main chamber receiving both atrioventricular orifices and giving rise to the posterior great vessel. The anterior great vessel arose from a smaller outlet chamber. The main finding was a grossly abnormal situation of the cardiac specialized tissue. Thus, in all 14 hearts the atrioventricular node was a small hypoplastic structure in the interatrlal septum. Connection between the atria and ventricles was made by way of an anterior node situated at the junction of the right atrial appendage with the anterior interatrial septum. From this node an atrioventricular bundle descended in the outflow tract of the posterior vessel and lay on the right margin of the foramen between the main and outlet chambers. The bundle was found in this position in both dextro- and levo-bulboventricular loops. The bundle bifurcated astride the septum between the chambers, and a typical left bundle branch passed into the main chamber. Right bundle branch tissue was always present in the outlet chamber. In two hearts with complete heart block neither node made contact with ventricular myocardium, but specialized tissue was present in the ventricular subendocardium. Because these findings have significance for surgical treatment, it is important to distinguish such hearts from “common” ventricles in which the specialized tissue is reported to lie in the posterior position. The mode of development of the abnormal tissue is discussed, with particular reference to the presence of anterior nodal tissue in normal human development. Finally, it is concluded that either of two concepts could account for the morphogenesis of the anomaly and that further studies are necessary to determine the correct hypothesis.

Dual atrioventricular nodal pathways: a common electrophysiologic response in children.

Electrophysiologic investigation was performed on 61 children and young adults during evaluation of either cardiac dysrhythmia or pre- or postoperative congenital heart disease. The results of these studies were reviewed retrospectively to determine if longitudinal dissociation of the atrioventricular node (AVN) was present. Dual AVN pathways were detected by the atrial extrastimulus technique, using His bundle electrograms. A discontinuous H1H2 response curve indicated the presence of dual AVN pathways. There was a higher incidence of dual AVN pathways in patients with clinically evident paroxysmal supraventricular tachycardia (PSVT) than in those without PSVT. Dual AVN pathways were equally prevalent in children with corrected and uncorrected congenital cardiac defects.

Follow-up results of balloon angioplasty of native coarctation in neonates and infants

The purpose of this study is to present intermediate-term results of balloon angioplasty of native aortic coarctation in neonates and infants less than 1 year of age. During a 60-month-period that ended in January 1990, 19 infants ages 3 days to 12 months (median, 2.5 months), underwent balloon angioplasty of native coarctation with resultant reduction in peak-to-peak systolic pressure gradient from 39 +/- 12 mm Hg (mean +/- SD) to 11 +/- 7 mm Hg (p less than 0.001) and increase in coarctation segment size from 2.2 +/- 0.8 mm to 4.7 +/- 1.0 mm. None required immediate surgical intervention. Thirteen of the 19 (68%) had severe associated cardiac defects. There was one death (5%) 2 days after balloon angioplasty, and it was related to associated cardiac defect. One infant was lost to follow-up. It is too soon to restudy one infant. The remaining 16 infants had clinical (36 +/- 18 months) and catheterization (12 +/- 4 months) follow-up data. The residual coarctation gradient (22 +/- 15 mm Hg) and coarcted segment size (4.4 +/- 1.6 mm) remain improved (p less than 0.01) when compared with pre-balloon angioplasty values. Five of the 16 (31%) infants (four were neonates at the time of balloon angioplasty) had evidence for recoarctation (defined as gradient greater than 20 mm Hg) and underwent surgical resection (two) or repeat balloon angioplasty (three), all with success. None developed aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Causes of restenosis after balloon valvuloplasty for valvular pulmonary stenosis

Abstract Several short-term and a few intermediate-term results of balloon valvuloplasty for relief of valvular pulmonary stenosis (PS) have been reported.1–11 Recurrence of valve stenosis has been reported,2,3–6,8,10 but the reasons for the restenosis at intermediate-term follow-up have been studied only to a limited degree.2,3,5,6,12 The present study investigates the causes of recurrence of PS after balloon valvuloplasty.

Intermediate-term follow-up results of balloon aortic valvuloplasty in infants and children with special reference to causes of restenosis

Sixteen infants and children with valvular aortic stenosis underwent percutaneous balloon aortic valvuloplasty over a 36-month period ending August 1988. The mean systolic pressure gradient across the aortic valve decreased from 72 +/- 21 (mean +/- standard deviation) to 28 +/- 13 mm Hg (p less than 0.001) immediately after valvuloplasty; the degree of aortic insufficiency did not significantly increase. Follow-up catheterization (in 10 patients) and Doppler data (in all 16 patients) were available 3 to 32 months (mean 12 months) after valvuloplasty and revealed a residual aortic valvular gradient of 37 +/- 23 mm Hg, which continues to be significantly lower (p less than 0.001) than that before valvuloplasty. There was no increase in aortic insufficiency. On the basis of follow-up data, the 16 children were divided into 2 groups: group I with good results (gradients less than or equal to 49 mm Hg), 12 patients; and group II with poor results (gradients greater than or equal to 50 mm Hg), 4 patients. All 4 patients in group II required repeat balloon valvuloplasty or surgical valvotomy; none from group I required these procedures. Seventeen general, anatomic, physiologic and technical variables were examined by a multivariate logistic regression analysis to identify factors associated with restenosis; these risk factors were: age less than or equal to 3 years; and immediate aortic valvular gradient after valvuloplasty greater than or equal to 30 mm Hg. The immediate and intermediate-term follow-up results of balloon aortic valvuloplasty are encouraging. Recognition of the risk factors may help identify potential candidates for recurrence.(ABSTRACT TRUNCATED AT 250 WORDS)

Significance of infundibular obstruction following balloon valvuloplasty for valvar pulmonic stenosis

This study was designed to define the prevalence and significance of infundibular obstruction following balloon pulmonary valvuloplasty. Thirteen of 62 children had infundibular gradients prior to valvuloplasty; five of these disappeared following balloon valvuloplasty. Five other children without pre-valvuloplasty infundibular gradients but with angiographic infundibular narrowing developed new infundibular gradients following valvuloplasty. Propranolol was administered to six children because of severe infundibular constriction, with improvement. None required surgical intervention. At follow-up the infundibular gradients either diminished or disappeared. The infundibular gradients appear to be more frequent with increasing age and severity of pulmonary valvar obstruction. Children developing systemic or suprasystemic right ventricular pressures after balloon pulmonary valvuloplasty may be candidates for propranolol therapy. Regression of the infundibular stenosis at follow-up can be expected, as has been observed after surgical pulmonary valvotomy. Because the infundibular obstruction can be successfully managed, balloon pulmonary valvuloplasty remains the treatment of choice for isolated valvar pulmonary stenosis. Use of balloon valvuloplasty in children less than 5 years of age and/or prior to development of pulmonary gradients in excess of 80 mm Hg may reduce the chance for development of infundibular reaction.

CARDIAC DIASTOLIC FUNCTION IN PEDIATRIC PATIENTS RECEIVING DOXORUBICIN

The purpose of the study was to compare systolic and diastolic function in pediatric patients treated with doxorubicin. Left ventricular function was evaluated in 61 children prior to and following chemotherapy. None had clinical evidence of cardiac decompensation prior to treatment. All received relatively low cumulative doses of doxorubicin; the majority received the drug by continuous infusion. Systolic function was estimated using fractional shortening; diastolic function was estimated using A wave velocity, E wave velocity, E to A ratio, and deceleration time. There was a small but significant decline in systolic cardiac function as estimated from changes in fractional shortening that could not be appreciated in any of the measured parameters of diastolic function. A variety of reasons that could be responsible for the absence of significant changes in diastolic function are discussed. For the present, estimations of systolic function are preferred over the studied parameters of diastolic function in the evaluation of cardiac status in pediatric patients receiving doxorubicin containing regimens.