McGoon, Dwight C.

Two patients with corrected transposition of the great arteries and ventricular rotation are described. The ventricular rotations encountered were about the longitudinal and the anteroposterior axes, respectively. The ventricular rotation affected the plane of the ventricular septum, the inflow and outflow tracts of the ventricles, and the interrelationship of the great arteries. Surgical closure of an associated ventricular septal defect was not without its problems.

Six years have passed since the first successful surgical correction of truncus arteriosus. A review of our experience enables some conclusions regarding the operation. Patients with mild or moderate truncal valve incompetence do not need truncal valve replacement. Patients with severe truncal valve incompetence require valve replacement, which is associated with a significantly increased surgical mortality. The surgical mortality is not increased in hemodynamically favorable patients who have only one pulmonary artery. However, these patients are especially likely to have early development of severe pulmonary vascular disease. The surgical mortality for the patient with uncomplicated disease and two pulmonary arteries, with pulmonary resistance of less than 8.0 units m 2 , is 10%. In patients with pulmonary resistance between 8.0 and 12 units m 2 , the mortality is approximately three times greater. Patients with pulmonary resistances greater than 12.0 units m 2 are probably inoperable. Different hemodynamic criteria must be applied in assessing the operability of patients with a single pulmonary artery. A systemic arterial oxygen saturation less than 85% in a patient with two pulmonary arteries and without pulmonary artery stenosis or a pulmonary artery band usually indicates inoperability. Elective operation usually is deferred until a patient is four years old, but if the patient's clinical condition warrants, the procedure can be done at any time after the age of one year, with a good chance of success. Follow-up on most operated patients has been encouraging.

From 1957 through 1971, 18 patients whose ages ranged from 10 months to 18 years underwent surgical correction of tetralogy of Fallot with absent pulmonary valve. All patients had associated pulmonary arterial aneurysms; in two the left pulmonary artery also was absent. Right middle lobectomy had been performed previously on one patient for lobar emphysema; seven other patients had recurrent pulmonary infections. The ventricular septal defect was closed with a patch in 12 patients and by direct suture in 6. Concomitant infundibular resection was done in all. In four the narrow pulmonary valve annulus was enlarged with an outflow patch, and multiple radial incisions were made in the valve annulus in seven others. The pulmonary arterial aneurysms were not resected in any patients. There were three hopsital deaths (17%) and two late deaths. Complete heart block developed intraoperatively in three patients, all operated on prior to 1963, contributing to the early death of one patient and to the late deaths of the other two. In a follow-up of all 13 survivors at 8 months to 15 years (median 6 years), results were excellent and equal to those of patients who have undergone repair of tetralogy of Fallot with pulmonary valve.

Among certain patients with cardiovascular malformations, a common phenomenon is a ventricular septal defect and absence of anatomic origin of the pulmonary arterial supply from the heart. In this situation, true pulmonary arteries may be present or absent. In the latter case, the pulmonary arterial supply comes through bronchial arteries. When true pulmonary arteries are present, the left and right pulmonary arteries either may be in continuity at their origins (confluence) or they may arise from separate sites (nonconfluence). When confluence is present, the two pulmonary arteries may arise either from an atretic pulmonary trunk or from certain forms of persistent truncus arteriosus. Pulmonary atresia may be localized to the proximal end of the pulmonary trunk or diffuse in this vessel. When nonconfluence is present, each pulmonary artery arises separately from one of three possible sources as follows: (1) a form of persistent truncus arteriosus, (2) through ducti arteriosi from the aortic arch system, or (3) through bronchial arteries from the descending aorta.

Five patients have had the common features of pulmonary atresia or severe stenosis associated with a septal defect and a coronary artery-to-pulmonary artery (CA-PA) fistula. Four had pulmonary valvular atresia, and one had severe pulmonary stenosis. In all five, the CA-PA fistula contributed the principal component of the pulmonary blood flow. Cyanosis, continuous murmur, right ventricular hypertrophy, and decreased or normal pulmonary vascularity were frequent clinical manifestations, but angiocardiography was required to establish the diagnosis. The fistula was a side-to-side communication between the left coronary artery and the main pulmonary artery in each of the five patients. The dilated proximal coronary artery connecting the aortic root with the pulmonary artery gave a unique angiocardiographic appearance distinguishing it from truncus arteriosus or aorticopulmonary window. It is suggested that this unique angiocardiographic appearance be called an "aorticopulmonary tunnel." The surgical repair of this anomaly is closely related to that for severe tetralogy of Fallot and should involve a comparable risk and achieve a comparable result.

Cellular energy substrates and metabolites, electrolytes, oxygenation, and acid-base balance, in arterial and coronary sinus blood of seven adult patients who died after valvular replacements, were studied and compared with these measurements from five patients having aortic replacement who survived. Six of the patients were in New York Heart Association class IV. All but one died within 24 hr of acute circulatory failure, with excessive bleeding being a contributing factor. Plasma potassium and osmolality remained higher in the first postoperative hours in nonsurvivors. Ketone bodies, growth hormone, and lactate levels rose precipitously as shock became severe. Increased arterial blood osmolality and potassium, plus a still-rising lactate concentration, were evident 2 hr after operation in patients who died in the next 24 hr. Low cardiac output, hyperosmolality, and the degree of lactic acidosis were the only early changes predicting the fatal outcome.

The results of complete repair of double-outlet right ventricle with pulmonic stenosis in 22 Mayo Clinic patients were analyzed. The overall mortality rate was 32%. Since 1960, the mortality rate has been reduced to 16%. Anomalies of the distribution of the right coronary artery, a second ventricular septal defect of the atrioventricular canal type, and significant residual pulmonic stenosis were associated with a higher mortality rate. The difficulties in the diagnosis of this uncommon condition are emphasized. Complete repair is best carried out after the patient is 4 years old. A systemic-to-pulmonary arterial shunt is the procedure of choice for those who are younger than this. In the occasional patient with anomalous distribution of the right coronary artery which precludes adequate relief of the pulmonic stenosis, use of an aortic homograft from the right ventricle to the pulmonary artery should be considered.