Percutaneous balloon valvuloplasty in neonates with critical aortic stenosis.

Percutaneous balloon valvuloplasty was attempted in 10 newborn infants with critical aortic valve stenosis and severe congestive heart failure. Three had a very small left ventricle and aortic anulus. In one infant, the aortic valve could not be passed, and in another infant, a technical error resulted in severe valvular damage, aortic insufficiency and death. Among the eight patients who had effective dilation, the stenosis was relieved in seven as assessed by a significant decrease in transvalvular pressure gradient, improvement of left ventricular contraction and eventual inversion of the ductal shunting. The procedure failed in the only patient whose dilation was performed with an undersized balloon. Aortic insufficiency occurred in three infants and was severe (perforated cusp) in one, moderate in one whose valve was dilated with an excessively large balloon and mild and transient in one. None of the three infants with a very small left ventricle recovered (two died and one underwent cardiac transplantation). Among the seven infants with a left ventricle of acceptable size, three underwent subsequent aortic valvotomy; one of these died and two bad good results. The remaining four are doing well 16 +/- 5 months later (mean +/- SD) with mild to moderate residual aortic stenosis and normal left ventricular function. In conclusion, percutaneous balloon valvuloplasty is an acceptable alternative to surgery in neonates with critical aortic valve stenosis. Incidence of complications and good relief of the obstruction depend on a careful technique. Immediate results are similar to those of surgery. Late prognosis depends on the quality of the left heart structures.

Concealed paroxysmal atrioventricular block: diffuse congenital atrioventricular conduction system disorder with nonpropagated His bundle depolarizations.

A 2 1/2-year-old girl with bradycardia and left bundle branch block at birth began to experience "night cries" when deeply asleep. Electrophysiological study demonstrated congenital diffuse atrioventricular conduction disease with concealed paroxysmal atrioventricular block, nonpropagated His bundle depolarizations, severe sinus node abnormality, and a low atrioventricular junctional escape rhythm with probable reciprocation. After pacemaker implant, the "night cries" ceased.