S. Gilbert Blount

Congenital unilateral absence of a pulmonary artery. The importance of flow in pulmonary hypertension.

Abstract This review and supporting experiments in which the left pulmonary artery was ligated on the first day of life, have clearly implicated an increased pulmonary blood flow from the time of birth as an important factor in the genesis of pulmonary hypertension. Ninety-eight cases of unilateral absence of a pulmonary artery, including four new cases, have been collected from the worlds literature and are reviewed in this paper. This lesion is frequently undiagnosed and may be more common than is generally appreciated as shown by the marked increase in case reports in the past ten years. The blood supply to the affected lung has been explained on an embryologie basis, and two distinct embryologic faults have been implicated. The incidence of pulmonary hypertension in the isolated cases was 19 per cent, and when combined with a cardiovascular shunt the incidence was 88 per cent. In view of the high incidence of pulmonary hypertension when UAPA is associated with a cardiovascular shunt, it is important to recognize these patients at an early age and correct the associated shunt to prevent or reverse pulmonary hypertension, if possible. It is evident that this lesion must be considered in the differential diagnosis of pulmonary hypertension and cyanotic congenital heart disease.

Perforation of the interventricular septum complicating myocardial infarction

Summary Eight cases of ventricular septal perforations are presented, and the present literature, consisting of 132 cases, is reviewed. The diagnosis of this condition should be strongly considered when a patient with an acute myocardial infarction suddenly develops a blowing systolic murmur along the lower left sternal border. Recognition is of importance in a consideration of the prognosis, as less than 10 per cent survive one year. In one patient, cardiac catheterization was performed in an attempt to confirm the diagnosis, and in two patients the unusual combination of a ruptured septum and a ruptured ventricle was present. The differential diagnosis has been discussed, with particular attention to the differentiation of septal perforation from papillary muscle rupture.

Tolazoline hydrochloride (Priscoline) An effective pulmonary vasodilator

Abstract Eight infants and young children who had ventricular septal defects and high pulmonary vascular resistances were carefully selected to illustrate the pulmonary vasodilator effects of tolazoline. In each of these 8 patients, tolazoline produced a marked reduction in pulmonary hypertension (average decrease, 28 mm. Hg) and an impressive decrease in pulmonary vascular resistance (over 50 per cent) to normal levels. The effects of tolazoline on the cardiovascular dynamics of 11 normal subjects were also examined and found to be minimal. When tolazoline is delivered directly into the pulmonary artery in a dose of 1 mg. per kilogram over 45 seconds, it is highly effective in relieving pulmonary vasoconstriction.

The Persistent Ostium Primum Atrial Septal Defect

Five patients with an ostium primum type of atrial septal defect were studied by clinical and laboratory methods and the diagnosis was verified either at the time of open-heart surgery and/or at autopsy. The atrioventricular valves formed the floor of the defect and were deformed in 4 of the 5 patients. Mitral insufficiency was present as a result of this valvular deformity in these four patients. This valvular deformity resulted in a high pitched blowing systolic murmur, audible over the apical and lower left sternal areas, and left axis deviation and indications of left ventricular hypertrophy, determined by electrocardiography. The deformity of the mitral valve is considered to be the basis for these variations from the typical findings found in the patient with an ostium secundum type of atrial septal defect and make the differential diagnosis of the persistent ostium primum possible under these circumstances.

Persistent left superior vena cava

Abstract On the basis of our cases as well as the data in the literature we can conclude that discovery of a left superior vena cava during cardiac catheterization or angiocardiography is of great importance both from the clinical and surgical standpoint. It is clinically important because it indicates the probable association with other congenital anomalies and especially with a left-to-right shunt at the atrial level, and surgically important because it indicates, prior to operation, certain technical procedures which will be necessary to prevent disastrous complications at time of cardiac surgery.

Isolated Valvular Pulmonic Stenosis Clinical and Physiologic Response to Open Valvuloplasty

The preoperative and postoperative clinical and physiologic data are presented in 10 patients with isolated valvular pulmonic stenosis. The valvulotomy was performed in five patients by the generally accepted blind ventricular approach, while in the remaining five patients the valvular surgery was accomplished by a direct pulmonary arterial approach. The physiologic data revealed uniform obliteration of the systolic pressure gradient from the right ventricle to the pulmonary artery in the patients operated by the direct technic in striking contrast to the inadequate and variable relief of stenosis by the transventricular approach.

Hypertrophy of the right ventricular outflow tract: A concept of the electrocardiographic findings in atrial septal defect

Abstract Evidence is presented to support the concept that the rSR′ pattern with a total QRS time of 0.08 to 0.10 seconds observed in certain congenital and acquired lesions—but predominately atrial septal defects—is due to hypertrophy of the right ventricular outflow tract rather than to incomplete right bundle branch block.

Tetralogy of Fallot Clinical and Hemodynamic Spectrum of Combined Pulmonary Stenosis and Ventricular Septal Defect

The considerable body of clinical and physiologic data in patients with the tetralogy of Fallot that has been accumulated over the past 15 years now indicates that the original concept of the lesion as a single, fairly narrowly limited entity is no longer valid. The tetralogy can now be demonstrated to occupy a broad spectrum in the field of congenital cardiac anomalies, representing widely varying forms. While the entity has been termed a tetralogy, only 2 features, namely the pulmonary stenosis and the ventricular septal defect, are essential in the determination of the clinical and physiologic pattern that patients with this defect portray.

Electrocardiographic Changes During Hypothermia and Circulatory Occlusion

An analysis of the electrocardiograms from 25 patients during reduction of body temperature and total occlusion of circulation reveals marked abnormalities in conduction and rhythmicity. Hypothermia thermia was accompanied by slowing of the heart rate, depression of intracardiac conductivity, and by inhibition of the normal centers of impulse formation with resultant atrial arrhythmias. Circulatory occlusion during hypothermia was associated with a high incidence of ventricular arrhythmias. Changes noted in electric activity of the myocardium tended to return to normal with release of occlusion and warming of the patient.

Valvular Pulmonary Stenosis with Intact Ventricular Septum Clinical and Physiologic Response to Open Valvuloplasty

Clinical and physiologic studies have been carried out in 25 patients following surgical correction of congenital valvular pulmonary stenosis. The patients were operated upon under conditions of hypothermia and circulatory occlusion and the approach to the valve was transarterial, permitting plastic repair of the stenotic pulmonary valve with unimpaired vision and a dry operative field. The systolic pressure gradient between the right ventricle and the pulmonary artery has been completely abolished in 17 of the 25 patients. The results as reported in this series are considered to be superior to those obtained with the blind transventricular approach and the operative mortality certainly compares favorably with the transventricular approach.