Citations

At the Mayo Clinic, four patients were seen in whom a ventricular septal defect (VSD) of the atrioventricular (A-V) canal type was associated with an angle of nearly 90° between the intact atrial septum and the ventricular septum. The right atrium overrode the ventricular septum and communicated with both ventricles. A complex, straddling right A-V valve had some attachments in the left ventricle and resembled the common A-V valve of persistent common A-V canal. In three of the patients, a congenital mitral valve deformity also existed. Mild cyanosis probably is not a contraindication to surgical repair in such patients because right atrial blood may enter the left ventricle directly.

Data from 43 patients with common ventricle for whom satisfactory hemodynamic data are available are presented; these form 3.2% of the patients with congenital heart disease studied by means of catheterization at the Mayo Clinic. Selective biplane angiocardiography is essential for diagnosis of common ventricle. Associated cardiovascular anomalies are common, with transposition of the great vessels occurring in 84% of the patients. The right-to-left shunt present in all 43 patients results in desaturation of systemic arterial blood. The common ventricle receives all the systemic and pulmonary venous blood [see table in the PDF file] flows; yet complete mixing is uncommon in this chamber, for it occurred in only 16% of the patients who did not have severe pulmonary stenosis. Fifty-eight per cent had oxygenated blood directed preferentially to the systemic circuit ("favorable streaming"). This occurred most commonly with L-transposition and resulted in a higher oxygen saturation of systemic arterial blood. Obstruction to pulmonary flow (from pulmonary stenosis or pulmonary vascular disease) results in a larger right-to-left shunt and lower oxygen saturation of systemic arterial blood.

Introduction of a cardiac catheter into the pulmonary artery from the right heart is not possible in a substantial proportion of patients with transposition of the great vessels. It is necessary to obtain the pulmonary artery pressure and oxygen saturation value to evaluate the degree of pulmonary stenosis and the pulmonary vascular resistance. Twenty-three patients are described in whom this was accomplished by percutaneous suprasternal puncture. There was no mortality and there were no significant complications. The technique appears to be safe and reliable.

The analysis and description of the preoperative and postoperative vectorcardiograms in tetralogy of Fallot are presented. The spatial orientation of the maximum QRS vectors to the right, anteriorly, and inferiorly in group I is indicative of right ventricular hypertrophy. In group II patients, the vectorcardiogram showed evidence of increased electrical activity of the left ventricle. Vectorcardiographic patterns of complete right bundle-branch block were noted in nine patients in group III.

Eighteen cases of stenosis of the branches of the pulmonary artery, seen at the Mayo Clinic, have been reviewed and subdivided into two main types: Type I, stenosis of the main branches of the pulmonary artery, 11 cases, and type II, stenosis of multiple peripheral branches of the pulmonary arteries, seven cases. Of special interest were two cases in which thrombosis occurred as a complication and one case in which surgical relief of multiple areas of stenosis in the peripheral branches of the pulmonary arteries was accomplished. Unexplained pulmonary hypertension necessitates further investigation, which includes cardiac catheterization for measurement of intracardiac pressure and frequently selective angiocardiography. Main branch or peripheral pulmonary artery stenosis should be suspected when a continuous murmur is heard or when poststenotic dilatations of the pulmonary artery branches or areas of decreased pulmonary vasculature can be perceived in the roentgenogram. Angiocardiography is the only technic that permits detailed anatomic evaluation of the entire pulmonary vasculature, especially in the cases associated with severe infundibular or valvular pulmonic stenosis. Stenosis of the branches of the pulmonary artery must be taken into account, when surgical repair of associated cardiovascular defects is considered. These lesions also might complicate anastomotic procedures involving the pulmonary artery in cyanotic patients.

Nineteen patients with ventricular septal defect and severe aortic valvular incompetence have been operated on at the Mayo Clinic. There were two early deaths and two late deaths. The ventricular septal defect was located high and anteriorly in the septum and was often small. Aortic valvular incompetence was due, in most cases, to a deformed, prolapsing right coronary cusp. Mild to moderate degrees of infundibular pulmonary stenosis coexisted in nine patients. Repair of the ventricular septal defect was readily accomplished in most cases by direct suture, and relief of obstruction to right ventricular outflow was effected, when required, by resection of the crista supraventricularis. Repair of the aortic incompetence was attempted by a variety of means, but the incidence of persistent significant regurgitation was high, except when prosthetic cusp replacement was used. It is currently our policy to defer operation in children unless there are significant symptoms. When the patient is past the age of about 12 to 14 years, operation is advised under proper circumstances, and it consists generally of suturing of the ventricular septal defect and replacement of the right coronary cusp of the aortic valve.

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.

Open operation by means of extracorporeal circulation has been used on 47 patients with congenital aortic stenosis at the Mayo Clinic between April 1955 and July 1, 1960; 33 patients had valvular stenosis, 11 had subvalvular stenosis, and three had supravalvular stenosis. The over-all operative mortality rate was 13 per cent; 6 per cent of patients with valvular aortic stenosis died in the hospital. Severe aortic insufficiency did not develop in any patient operated on for valvular aortic stenosis although a diastolic murmur was present after operation in some. Rarely, however, was the transvalvular gradient completely eliminated by operation although 90 per cent of the surviving patients were either asymptomatic or had definite clinical improvement. Late follow-up hemodynamic studies suggest that a persistent transvalvular gradient may regress in time. Relief of obstruction caused by subvalvular variety of aortic stenosis is difficult whether stenosis is localized or diffuse. Even in this gruop, however, it has been possible to achieve good results with careful attention to certain technical details. Patients with congenital aortic stenosis should be operated on before the development of the sequelae of severe left ventricular hypertension.

From March 1955 to April 1959, 174 patients with ventricular septal defect and 124 patients with ventricular septal defect associated with pulmonic stenosis were referred from the Section of Pediatrics of the Mayo Clinic for open intracardiac repair. Forty-eight of these 298 patients had complete heart block at some time following operation. Eighteen of the patients with heart block died in the immediate postoperative period, 18 had reversion to normal sinus rhythm, and 12 were discharged from the hospital with complete heart block. Three of these 12 patients died subsequently. Two died presumably as a direct result of complete heart block and a third died following a second open cardiac operation. Of the 9 surviving patients, 3 have had serious bradycardia or periods of asystole and 6 have no symptoms from heart block. One of 3 surgical technics was employed for all the patients in this study with variation in incidence of block with the use of each technic. Other factors that might relate to the incidence of heart block are discussed. The management of the patient with complete heart block both in the immediate post-operative period and after dismissal from the hospital is described.