Brandenburg, Robert O.

Patients who have pulmonary stenosis and ventricular septal defect usually have a right-to-left intracardiac shunt. This paper presents hemodynamic and clinical data on 11 patients who have pulmonary stenosis, ventricular septal defect and left-to-right shunts. Four of these patients also have defects in the atrial septum, and three have demonstrable bidirectional shunts. The level and direction of shunts were determined by blood oxygen-saturation data and indicator-dilution studies. Choice of the form of treatment to be used in patients such as these should be based largely on hemodynamic considerations. Many resemble patients with tetralogy of Fallot who have had a successful pulmonary valvotomy.

Atrial septal defect (ASD) of the fossa ovalis type was found in 16 members of one family and confirmed in 15 members at autopsy or surgery or by cardiac catheterization. Sinus rhythm was present in 12 affected members, 11 of whom had electrocardiographic evidence of prolonged atrioventricular (A-V) conduction. Five other family members without ASD also had prolonged A-V conduction. The pedigree chart suggests that the syndrome ASD with prolonged A-V conduction is the manifestation of a single mutant autosomal gene with dominant effect, a high degree of penetrance, and some variation in expressivity. Earlier reports of familial ASD showing the autosomal-dominant pattern of inheritance reveal a similar frequency of prolonged A-V conduction among affected persons. The great majority of cases of ASD are sporadic, with little likelihood of recurrence in subsequent sibs or children. We suggest, however, that when ASD of the fossa ovalis type is accompanied by prolonged A-V conduction, the genetic prognosis may be drastically changed to a risk of almost 50% that the condition will recur in subsequent sibs or children of affected persons.

Muscular obstruction to left ventricular outflow is a rare but serious occurrence. Eight cases in which this disease was anatomically proved are presented. The commonest symptoms are angina, dyspnea, and palpitations. Not uncommonly a family history of heart disease may be elicited. A systolic murmur along the left sternal border is the most characteristic physical finding, but a normal aortic second sound, the presence of third and fourth heart sounds, splitting of the second sound, and the absence of a diastolic murmur are all helpful clinical guides. Withdrawal pressures from the left ventricle reveal a characteristic infundibular pressure zone. Other hemodynamic findings include an anacrotic notch on the left ventricular pressure tracing, a rapidly ascending bisferious aortic pulse and a small compensatory beat after extrasystoles. Necropsy specimens reveal a grossly thickened interventricular septum as compared with normal and hypertrophied control hearts. Microscopic alterations are minimal. The etiology remains obscure but familial and developmental factors, either or both, appear to be implicated.