Congenital heart block: development of late-onset cardiomyopathy, a previously underappreciated sequela.

OBJECTIVE: We report 16 infants with complete congenital heart block (CHB) who developed late-onset dilated cardiomyopathy despite early institution of cardiac pacing. BACKGROUND: Isolated CHB has an excellent prognosis following pacemaker implantation. Most early deaths result from delayed initiation of pacing therapy or hemodynamic abnormalities associated with congenital heart defects. METHODS: A multi-institutional study was performed to identify common clinical features and possible risk factors associated with late-onset dilated cardiomyopathy in patients born with congenital CHB. RESULTS: Congenital heart block was diagnosed in utero in 12 patients and at birth in four patients. Ten of 16 patients had serologic findings consistent with neonatal lupus syndrome (NLS). A pericardial effusion was evident on fetal ultrasound in six patients. In utero determination of left ventricular (LV) function was normal in all. Following birth, one infant exhibited a rash consistent with NLS and two had elevated hepatic transaminases and transient thrombocytopenia. In the early postnatal period, LV function was normal in 15 patients (shortening fraction [SF] = 34 +/- 7%) and was decreased in one (SF = 20%). A cardiac pacemaker was implanted during the first two weeks of life in 15 patients and at seven months in one patient. Left ventricular function significantly decreased during follow-up (14 days to 9.3 years, SF = 9% +/- 5%). Twelve of 16 patients developed congestive heart failure before age 24 months. Myocardial biopsy revealed hypertrophy in 11 patients, interstitial fibrosis in 11 patients, and myocyte degeneration in two patients. Clinical status during follow-up was guarded: four patients died from congestive heart failure; seven required cardiac transplantation; one was awaiting cardiac transplantation; and four exhibited recovery of SF (31 +/- 2%). CONCLUSIONS: Despite early institution of cardiac pacing, some infants with CHB develop LV cardiomyopathy. Patients with CHB require close follow-up not only of their cardiac rate and rhythm, but also ventricular function.

Classic versus modified Blalock-Taussig shunts in neonates and infants.

Between July 1979 and October 1984, 61 systemic-pulmonary arterial shunts were created in 45 patients. Clinical and angiographic results with 23 classic Blalock-Taussig shunts (BTSs) and 35 modified Blalock-Taussig shunts (MBTSs) with polytetrafluoroethylene grafts between the subclavian and pulmonary arteries were compared. Forty-three of the patients studied were infants: 28 were less than 1 month old, and 19 were less than 1 week old. Weights were 1.1 to 19 kg (mean 2.9 kg). Diagnoses were complex tetralogy of Fallot (18 patients), transposition of the great arteries with small left ventricle or left ventricular outflow tract obstruction (six patients) pulmonary atresia (seven patients) with intact ventricular septum (three) and ventricular septal defect (four), tricuspid atresia (four patients), univentricular heart (six patients), atrioventricular septal defect (canal) with pulmonary stenosis (three patients), and double-outlet right ventricle (one patient). Comparison groups were concurrent and were equivalent for age, weight, and complexity of anomaly. Patients were removed from the study population at the time of subsequent open heart surgery or at death. All patients were followed for a minimum of 6 months and for up to 5 1/2 years (BTS 1 1/2 to 5 1/2 years, mean 33 months; MBTS 6 months to 3 years, mean 20 months). There were no intraoperative deaths in either group. Among the 23 BTSs, three failed at 1, 3, and 19 days, resulting in two deaths (17%). One premature infant died despite a second shunt, one died during attempted intracardiac repair at 13 days of age, and the other was well after revision of the shunt. Eight patients underwent subsequent intracardiac repair 1 to 5 years (mean 34 months) after the initial procedure. Another four patients died from complex intracardiac anomalies with patent shunts. Three patients are alive 2 to 4 years after receiving shunts and have not undergone subsequent surgery. Late postoperative angiograms demonstrate a disturbing incidence (21%) of stenosis and right pulmonary arterial deformity despite satisfactory immediate postoperative studies and good clinical function. Eight patients required a second shunt, two for anatomic discontinuity of the pulmonary arteries and six because of inadequate blood flow through the first shunt. Among the 35 patients receiving the MBTS, two required early revision (technical error and ductal tissue at the anastomosis). There were no shunt-related deaths, but three (6%) occurred within 30 days of operation from left ventricular infarct, cerebral hemorrhage, sepsis, and severe aortic stenosis with arrhythmias.(ABSTRACT TRUNCATED AT 400 WORDS)

Pulsed Doppler and two-dimensional echocardiographic findings in aortico-left ventricular tunnel.

Two-dimensional echocardiography was used to make the anatomic diagnosis of aortico-left ventricular tunnel in a 1 day old infant. Pulsed Doppler echocardiography allowed directional flow to be determined within the tunnel. The findings were confirmed by cardiac catheterization and by direct visualization at the time of surgical repair. Aortic valve insufficiency was excluded before and after surgery using pulsed Doppler echocardiography. The anatomy and physiology of aortico-left ventricular tunnel can thus be documented using noninvasive techniques.

Hypoplastic left heart syndrome with dysplastic pulmonary valve with stenosis.

A dysplastic pulmonic valve in hypoplasia of aortic tract complex has not been dealt with in the literature. The recent attempted surgical correction for hypoplasia of aortic tract complex has given some hope of survival in this entity. The integrity of the tricuspid and pulmonic valves is important while considering total surgical correction. We describe three hearts of hypoplasia of aortic tract complex with dysplastic pulmonic valve. The echocardiographic recognition and the significance of the dysplastic nature of the pulmonary valve in the light of surgery are emphasized.

Subclavian flap repair of coarctation of the aorta in neonates. Realization of growth potential?

The subclavian flap repair for coarctation of the aorta allows potential for growth by utilizing autogenous tissue. Although well documented in young children, its promise in the tiny neonate warrants further evaluation. Since August, 1979, 29 patients, including 24 infants, have undergone subclavian flap repair at the University of Maryland Hospital. Weights ranged from 1.4 to 5 kg (mean 3.2 kg). All patients less than 6 months old had associated intracardiac defects and were in severe congestive failure. Fifteen responded to preoperative prostaglandin infusions. The overall early mortality was 14%; among the neonates it was 21%; and among those operated upon within the first week of life, 33%. There was one intraoperative death among the eight patients who underwent simultaneous pulmonary artery banding. There were no deaths among patients older than 5 days at operation. Four of the five neonates who died had some variant of hypoplastic left heart syndrome, with severe stenosis or atresia of the systemic atrioventricular valve, critical aortic stenosis, or hypoplastic left ventricle. Twenty-two survivors continue to do well up to 3.7 years postoperatively (mean follow-up 26 months). At follow-up all patients are normotensive with brisk lower extremity pulses. Patients now weigh 1.3 to 6.9 (mean 2.3) times their operative weight, and only one patient has a measured arm-to-leg gradient greater than 10 mm Hg (mean gradient 3.7 mm Hg). Seven of the neonates have undergone repeat catheterization, and all had satisfactory growth of the subclavian flap segment of repair and no gradient. Two older patients (3 and 4 years old at operation) have undergone exercise testing 3.7 years after repair, with peak exercise gradients of only 7 and 15 mm Hg. We therefore continue to utilize this technique for the treatment of coarctation even in tiny neonates.

Familial atrial septal defect with prolonged atrioventricular conduction.

This report describes a family with frequent recurrence of congenital heart disease in multiple generations. Eight members had atrial septal defect (ASD) of the fossa ovalis type and seven members had other forms of congenital heart disease. One branch of the pedigree showed a predominance of ASD with prolonged atrioventricular (A-V) conduction and initially suggested an autosomal dominant gene effect. A variety of other forms of congenital heart disease were found in several first degree relatives of those with ASD as well as in more distant relatives. The variability of congenital heart disease in this pedigree is compatible with the polygenic mode of inheritance. Definition of the inheritability of congenital heart disease in a specific family has important consequences in the determination of the recurrence risks for all family members.

Spectrum of sinus node dysfunction in two siblings.

Two siblings, ages 14 and 23, with various features of sinus node dysfunction have been reported. Sinus bradycardia was the presenting feature in both patients. During the follow-up period both patients developed various types of ectopic rhythms which increased with exercise. One of them developed "silent atrium" at the age of 23 and had cerebral embolus as a complication. The other patient had frequent syncopal episodes and had to be treated with a combination of electronic pacemaker and antiarrhythmic drugs.