Swan, H.J.C.

Hemodynamic studies were made 2 weeks after repair of tetralogy of Fallot in 18 cases and 2 months to 6 years after operation in 5 cases. Intracardiac and intravascular pressures, oxygen uptake, arteriovenous oxygen content difference, cardiac output, heart rate, stroke index, and pulmonary and systemic resistance were measured. Residual intracardiac shunts and residual pulmonary stenosis and incompetence were assessed. Results were compared with similar studies on postoperative days 1, 2, and 3. Further insight into patterns of convalescence as well as into the favorable hemodynamic state usually pertaining after repair are provided by these data.

Clinical, hemodynamic, and angiocardiographic findings are described in seven cases of congenital mitral insufficiency. The volumes and changes in volume of the left atrium and left ventricle were calculated from the angiocardiograms and were found to be increased above the range of normal. Left ventricular stroke volumes thus obtained were compared with forward flows calculated from indicatordilution curves in order to quantitate regurgitant flow. Regurgitant flows varied between 19 and 94 per cent of the total left ventricular ejection volume, and forward flow was maintained as a result of a considerable increase in left ventricular volume. The left ventricular ejection volume was 50 to 64 per cent of the end-diastolic volume.

Eighteen patients with the combination of ventricular septal defect and aortic insufficiency were studied. Nine also had infundibular pulmonary stenosis. Seventeen were treated by open-heart operations. The physical findings were those of a typical ventricular defect murmur and thrill together with an aortic insufficiency blow and a wide pulse pressure. A systolic murmur at the upper left sternal border with thrill is strongly suggestive of the additional lesion of infundibular pulmonary stenosis, but the presence or absence of infundibular pulmonary stenosis was indicated most accurately at cardiac catheterization and on inspection at operation. It was not of sufficient severity for signs of additional right ventricular hypertrophy to appear on the electrocardiogram. Retrograde aortography serves to demonstrate the severity of the aortic regurgitation. The problem of the surgical correction of these lesions will be the subject of a separate communication.

Closed-chest massage and defibrillation were used successfully in the management of six acute cardiac emergencies occurring in a cardiac catheterization laboratory. A modification of the Kouwenhoven method of closed-chest massage was used in infants and small children. It is concluded that open-chest resuscitation is usually unnecessary during cardiac catheterization.

In complete transposition of the great vessels, survival is possible only when a route of access exists by means of which venous blood may enter the lungs. This report concerns 2 patients in relatively good health in whom a high degree of mixing of venous and arterial blood occurred through an atrial septal defect. The diagnosis was established in both patients by cardiac catheterization.

The present studies are concerned with the effect of high oxygen inhalation on patients with atrial septal defects. The problem of the amount of pulmonary vascular resistance and the relative contribution of irreversible structural changes and vascular tone may be of important prognostic significance in evaluation of such patients for cardiac surgery.

Indicator-dilution curves were recorded by oximeters at the ears and the right radial artery following the injection of Evans blue (T 1824) into the superior vena cava and pulmonary arteries of 37 subjects who had no evidence of cardiovascular disease. The variability and ranges of various time and concentration components of these dilution curves are presented. These values can be used as standards of reference in the interpretation of abnormal dilution curves. Some of the factors responsible for the variability of these values in healthy subjects are assessed and discussed.

Analysis of accumulated experience with the repair of atrial septal defect in 119 adults has revealed several factors determinable preoperatively that appear to have a strong influence on the operative risk. These factors are related to the presence of pulmonary vascular disease or heart failure and contribute importantly to the selection of patients for operation.