M. Stijns

Early Balloon Dilatation of the Pulmonary Valve in Infants With Tetralogy of Fallot Risks and Benefits

BACKGROUND Balloon dilatation, an established treatment for pulmonary valve stenosis, remains a controversial procedure in tetralogy of Fallot. METHODS AND RESULTS Balloon dilatation of the pulmonary valve was performed in 19 infants with tetralogy of Fallot. Its effects on the severity of cyanosis, the growth of the pulmonary valve and pulmonary arteries, and the need for transannular patching were evaluated. Clinical, echographic, angiographic, hemodynamic, and operative data were analyzed. The procedure was safe in all, without significant complications. After balloon dilatation, systemic oxygen saturation increased from a mean value of 79% to 90%. This increase proved to be short-lasting in 4 patients, who required surgery before the age of 6 months. Balloon dilatation increased pulmonary annulus size in each case, from a mean value of 4.9 to 6.9 mm (P < .001). This gain in size remained stable over time, with a mean Z score of -4.8 SD before dilatation, -3.1 SD immediately after the procedure, and -2.7 SD at preoperative catheterization (P < .001). Pulmonary artery dimensions remained unchanged immediately after balloon dilatation but increased at follow-up from a Z score mean value of -2.5 to -0.06 SD and from -2.2 to 0.04 SD for right and left pulmonary arteries, respectively (P < .001). At the time of corrective surgery, the pulmonary annulus was considered large enough to avoid a transannular patch in 69% of the infants. This represented a 30% to 40% reduction in the need for a transannular patch compared with the incidence of transannular patch expected before balloon dilatation. CONCLUSIONS Pulmonary valve dilatation in infants with tetralogy of Fallot is a relatively safe procedure and appears to produce adequate palliation in most patients. It allowed the growth of the pulmonary annulus and of the pulmonary arteries, resulting in a mean gain of 2 SD for those structures.

Computer interpretation of pediatric orthogonal electrocardiograms: statistical and deterministic classification methods.

Statistical multivariate and conventional deterministic methods of computerized interpretation of the electrocardiogram (ECG) were compared in the analysis of 1711 pediatric orthogonal ECGs validated by nonelectrocardiographic criteria on the basis of clinical and anatomic diagnoses. Among 642 children catheterized for the evaluation of congenital heart disease, there were 140 patients with left ventricular hypertrophy, 299 with right ventricular hypertrophy, and 203 with biventricular hypertrophy. A group of 1069 obviously healthy school children was studied as a control. The overall accuracy of multigroup ECG diagnosis was 85% and 79% for the statistical and deterministic methods, respectively. The diagnostic performances of both methods expressed in terms of sensitivity and predictive value were the highest for normal children and those with right ventricular hypertrophy and lowest for children with biventricular hypertrophy. The statistical method was more sensitive in the diagnosis of left ventricular hypertrophy (74% vs 64%), right ventricular hypertrophy (86% vs 83%), and biventricular hypertrophy (62% vs 50%). Mutual agreement for a correct diagnosis by the two methods was 83% for normal children and 82% for those with right ventricular hypertrophy but only 61% for children with left ventricular hypertrophy and 39% for those with biventricular hypertrophy. In conclusion, better classification results are obtained with statistical multivariate techniques as compared with conventional deterministic analysis, but both methods of ECG interpretation are complementary and their combination in the same electrocardiographic computer program can improve diagnostic accuracy.

Influence of age on atrioventricular conduction intervals in children with and without atrial septal defect

His bundle electrograms were recorded in 42 patients with secundum atrial septal defects (ASD) and in 50 controls, aged 1 month to 16 years, in normal sinus rhythm and with normal PR intervals. Intervals PA (P less than 0.01) and PR (P less than 0.02) were found to be significantly prolonged in ASD patients. Analyzing the results according to age, a significant increase for intervals AH (P less than 0.05), HV (P less than 0.001) and PR (P less than 0.001) was noted in the oldest ASD children as compared to the younger ASD children, whereas in controls only the PR interval was found to be significantly prolonged (P less than 0.05) in the oldest subgroup. Under the age of three years, atrioventricular conduction intervals were not significantly different whether or not an ASD was present. However, in older children with ASD as compared to controls, a significant increase was noted for interval PA (P less than 0.03) in children four to eight years old and for intervals HV (P less than 0.01) and PR (P less than 0.001) in children 9 to 16 years old. ASD patients showed a more significant correlation with age for interval PR with a significantly steeper slope of the regression line. Results show the impact of ASD on AV conduction to be age-related, with involvement not only of the PA interval but also of the HV interval.

Atrioventricular-conduction and Right Atrial Volume in Children With and Without Secundum Atrial Septal-defects

Atrioventricular conduction intervals and right atrial end-diastolic volumes were studied in 43 patients (26 with secundum atrial septal defect and 17 controls) to test the hypothesis that the increase in intra-atrial conduction in atrial septal defect is due to right atrial dilatation. There was no relation between any of the atrioventricular conduction intervals and right atrial dilatation. The PH, PR, and AH intervals were, however, related to both age and the RR interval.