[Dilatation of critical aortic value stenosis in infants under 3 months of age. Our experience from 15 cases].

Between April 1988 and October 1992, 15 consecutive infants aged less than 3 months (average 17 days) with critical valvular stenosis underwent balloon dilatation. Thirteen were less than 1 month old and all had low output syndromes. The diagnosis and follow-up assessments were made by Doppler echocardiography. Before valvuloplasty the maximum instantaneous gradient was 75 +/- 34 mmHg. The average diameter of the aortic ring was 6.8 +/- 1.3 mm. Seven patients had aortic rings with diameters of less than 7 mm. Ten infants had a right-to-left shunt via a patent ductus arteriosus and pulmonary hypertension. Dilatation was performed after surgical denudation of the left carotid artery: a balloon catheter with a diameter 0.85 times that of the aortic ring was used. After dilatation, the gradient was 26 +/- 18 mmHg (p < 0.001). Grade I aortic regurgitation was observed in 4 cases and Grade II in 2 cases. Eight patients died 1 to 100 days after dilatation (seven of low output and one sudden death). Of these patients, 6 had aortic rings < 7 mm diameter. The average follow-up was 20.6 +/- 15.5 months (range 2 to 48 months). None of the patients had a precordial or carotid diastolic murmur. The gradient increased with improvement in left ventricular function. Two patients had a stable Grade I aortic regurgitation. Carotid Doppler echocardiographic control examinations performed in 4 patients were normal. Poor prognostic factors were: aortic ring diameter < 7 mm (p < 0.025) and a low gradient after dilatation (p < 0.012).(ABSTRACT TRUNCATED AT 250 WORDS)