Transcatheter coil occlusion of perivalvular mitral leaks associated with severe hemolysis.

A 6-year-old malnourished child had persisting hemolysis after attempted valve repair and two surgeries for mitral valve replacement due to partial dehiscence of the valve ring. A modified catheter delivery system was utilized to deploy a total of six Gianturco coils. The hemolysis resolved and the patient was doing well 17 months later. The technique may be helpful in other patients with perivalvular mitral leaks. Cathet. Cardiovasc. Intervent. 49:64-67, 2000.

Pressure-overload hypertrophy is unabated in mice devoid of AT1A receptors.

Mechanisms controlling cardiac growth are under intense investigation. Among these, the renin-angiotensin system has received great interest. In the current study, we tested the hypothesis that the renin-angiotensin system was not an obligate factor in cardiac hypertrophy. We examined the left ventricular hypertrophic response to a pressure overload in mice devoid of the AT1A receptor, the putative major effector of the growth response of the renin-angiotensin system. Aortic banding produced similar transband gradients in wild-type and AT1A knockout mice. The left ventricular mass-to-body weight ratio increased from 3.44 +/- 0.08 to 5.62 +/- 0.25 in wild-type ascending aortic-banded mice. The response in the knockout mice was not different (from 2.97 +/- 0.13 to 5.24 +/- 0.37). We conclude that the magnitude of cardiac hypertrophy is not affected by the absence of the AT1A receptor and its signaling pathway and that this component of the renin-angiotensin system is not necessary in cardiac hypertrophy.

The effect of indomethacin tocolysis on fetal ductus arteriosus constriction with advancing gestational age.

OBJECTIVE: Our purpose was to determine whether continuing exposure to indomethacin tocolysis is associated with an increased incidence of constriction of the human fetal ductus arteriosus with advancing gestational age. STUDY DESIGN: Fetal echocardiograms were reviewed in 61 cases in which the pregnant women were treated for preterm labor with indomethacin (25 mg orally every 6 hours). Density function analysis and regression analysis were used to assess the effect of indomethacin tocolysis on ductal constriction with advancing gestational age. RESULTS: A total of 193 fetal echocardiograms were obtained for 72 fetuses. Ductal constriction developed in 50% of the fetuses ranging from 24.7 to 35.0 weeks' gestation. Fetuses with indomethacin-induced ductal constriction demonstrated a greater increase in systolic flow velocities with advancing gestational age compared with the nonconstricted group (p < 0.05). Constriction was detected at a mean gestational age of 30.9 +/- 2.3 weeks at an average of 5.1 +/- 6.0 days after initiation of therapy. Ductal constriction occurred by 31 weeks' gestation in 70% of the affected fetuses. After discontinuation of indomethacin therapy, all follow-up echocardiograms demonstrated a return to nonconstricted ductal flow velocities. No significant adverse neonatal outcomes were attributed to indomethacin use. CONCLUSIONS: A dramatic yet reversible increase in the incidence of indomethacin-induced ductal constriction occurs at 31 weeks' gestation. However, ductal constriction can occur at any gestational age. With indomethacin tocolysis, weekly fetal echocardiography is warranted for the duration of therapy.

Catheter ablation treatment of supraventricular tachycardia-induced cardiomyopathy.

OBJECTIVE: To investigate the efficacy of radiofrequency catheter ablation (RFCA) as an alternative nonpharmacological therapy for tachycardia-induced cardiomyopathy. DESIGN: A retrospective study of 8 pediatric patients (age range, 10 months to 21 years) who underwent RFCA for an incessant supraventricular tachycardia-induced cardiomyopathy. A patient's tachycardia was considered incessant if the tachycardia was present more than 75% of the time. The left ventricular shortening fraction, as measured by echocardiography, before and after ablation, was used as the index of cardiac function. Cardiomyopathy was defined as a left ventricular shortening fraction of 28% or less. RESULTS: Following RFCA, 7 patients had total resolution of their tachycardia and were discharged from the hospital with no antiarrhythmic medications. The remaining patient's tachycardia was modified by the catheter ablation and was subsequently controlled with flecainide acetate. With follow-up ranging from 9 months to 3 years, all patients have normal cardiac function as documented by echocardiography. No significant morbidity resulted from the catheter ablations. CONCLUSIONS: Tachycardia-induced cardiomyopathy is amenable to "curative" therapy with RFCA. Ventricular function returns to normal after the successful catheter ablation procedure.