Patrick A. Ongley

Anatomic types of single or common ventricle in man: Morphologic and geometric aspects of 60 necropsied cases

Abstract In 60 necropsied cases of single or common ventricle in man, four major unrelated ventricular malformations were found: (1) absence of the right ventricular sinus, in 47 cases (78%), designated type A; (2) absence of the left ventricular sinus, in 3 cases (5%), type B; (3) absence or rudimentary development of the ventricular septum, in 4 cases (7%), type C; and (4) absence of both ventricular sinuses and of the ventricular septum, in 6 cases (10%), type D. Three types of relationship between the great arteries were present: a normal (solitus) interrelationship, in 9 cases (15%), designated type I; d -transposition, the transposed aortic valve lying to the right (dextro, or d ), relative to the transposed pulmonary valve, in 25 cases (42%), type II; and l -transposition, the transposed aortic valve lying to the left (levo or l ), relative to the transposed pulmonary valve, in 26 cases (43%), type III. In none was the inversus interrelationship, type IV, displayed. Three types of visceral and atrial situs were found: solitus, or normal, in 50 cases (83%); inversus, an exact apparent mirror image of normal, in 2 cases (3%); and heterotaxy, the uncertain visceral and atrial situs associated with asplenia, in 8 cases (13%). The 60 cases were classified segmentally, according to the anatomy of the three cardiac segments: the great arteries, the ventricular sinuses, and the atria. The classic single ventricle with a rudimentary outlet chamber was found morphologically to be a large left ventricle with a right ventricular infundibulum, the sinus of the right ventricle being absent (type A). The myocardium of the right ventricular infundibulum, of the right ventricular sinus, and of the left ventricular sinus was identified by the distinctive gross morphologic characteristics of each. The planes of the atrial and ventricular septa, and the relationships between the great arteries at the semilunar valves, were measured as projections upon the horizontal plane, relative to the anteroposterior line. An approach to cardiac anatomy is presented which is segmental, morphologic and geometric. This approach has angiocardiographic, electrocardiographic and embryologic applications.

Complete Repair of Transposition of the Great Arteries with Pulmonary Stenosis A Review and Report of a Case Corrected by Using a New Surgical Technique

Complete surgical correction of transposition of the great arteries associated with subvalvular pulmonary stenosis carries a high mortality rate. A new surgical technique that achieves redirection of the ventricular outflows and relieves pulmonary stenosis by bypassing it, was successfully used to repair complete transposition of the great arteries associated with ventricular septal defect (VSD) and valvular and subvalvular pulmonary stenosis in a 14½-year-old patient. The repair consists of (1) division of the pulmonary artery, the cardiac end of which is oversewn, (2) repair of the VSD with a patch in such a way as to connect the left ventricle with the aorta, and (3) reconstruction of the pulmonary artery with an aortic homograft, including the aortic valve, which is anastomosed between the distal end of the pulmonary artery and the right ventricle.A review of the cases in which the current techniques were used indicates that the location and nature of the obstruction in the left ventricular outflow tract defies successful repair in most instances. Localized ridges and diffuse hypoplastic outflow tracts are recognized causes of obstruction, but anomalies of the mitral valve commonly contribute to or are the primary cause of subvalvular obstruction.

Congenital Stenosis of the Pulmonary Artery Branches

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.

Hypoplasia of ascending aorta. An unusual form of supravalvular aortic stenosis with special reference to localized coronary arterial hypertension.

Abstract Anomalies causing obstruction to blood flow in the aorta above the aortic valve, though rare, are of three types: (1) A localized zone of obstruction resembling a diaphragm in the ascending aorta; (2) localized narrowing of the ascending aorta and (3) uniform narrowing of the entire ascending aorta. In the case of the 2 year old boy reported, the last type of anomaly was present. In this case clinical data were suggestive of aortic stenosis, electrocardiographic findings of left and right ventricular overwork, and catheterization data of obstruction to the blood flow from the left ventricle, some degree of left ventricular failure, and left ventricular and pulmonary hypertension of moderate degree. An attempt to relieve the obstruction was not successful. At necropsy left ventricular hypertrophy, a suggestion of mitral insufficiency and uniform narrowing of the ascending aorta were found. In the coronary arteries the media was thickened, and deposition of elastic fibers was evident. These changes are attributed to systolic hypertension in the coronary vessels.

The Hemodynamics of Common (or Single) Ventricle

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.

Cor triatriatum: Hemodynamic and angiocardiographic diagnosis

Abstract Three cases of cor triatriatum are reported. Each patient presented with breathlessness and had signs of pulmonary hypertension, with electrocardiographic evidence of right ventricular overload. Plain radiographs of the chest showed moderate left atrial enlargement and changes indicative of pulmonary venous engorgement. Left atrial enlargement was confirmed in 2 cases by angiocardiography and was quantitated by measurement of the left atrial volumes. Hemodynamic studies revealed a considerable increase in the pulmonary arterial pressure (78 mm. Hg systolic and 32 mm. Hg diastolic to 125 mm. Hg systolic and 75 mm. Hg diastolic) and in the “wedge” pressure (28 mm. Hg systolic and 20 mm. Hg diastolic to 65 mm. Hg systolic and 18 mm. Hg diastolic), with normal left ventricular end-diastolic pressures. Angiocardiography was performed in 2 patients, and in each the intra-atrial diaphragm was clearly demonstrated. Removal of the left atrial diaphragm was successful in 2 patients. The third patient, who had severe pulmonary vascular disease, died on the first postoperative day.

Ventricular Septal Defect with Aortic Insufficiency A Clinical and Hemodynamic Study of 18 Proved Cases

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.

Ventricular Septal Defect with Aortic Valvular Incompetence Surgical Considerations

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.

Hemodynamics and evaluation for surgery of patients with complete transposition of the great arteries and ventricular septal defect

In complete transposition of the great arteries, the systemic and pulmonary circuits are parallel. Although the total flow in each circuit may be large, the volume of blood exchanged between the 2 circuits is relatively small and varies within narrow limits. However, this socalled effective flow alone is active in oxygen uptake from the lungs and delivery to tissues. The recirculated blood in each circuit does not enhance oxygen uptake and delivery in the pulmonary and systemic capillaries yet has a key role in determining pulmonary arterial and systemic arterial oxygen saturation. Flow and resistance levels in the 2 circuits may vary independently. Therefore, the flow and resistance ratios between the 2 circuits are often misleading. To assess accurately the status of the pulmonary vascular bed, the pulmonary circuit alone must be considered. The difference between the levels of pulmonary venous and pulmonary arterial oxygen content is a measure of pulmonary flow and resistance in the patient with complete transposition and a large ventricular septal defect and without significant pulmonary stenosis. At present, we consider the patient with an oxygen difference of 2.3 vol percent or less to be a suitable candidate for complete surgical repair. This patient will have a pulmonary arteriolar resistance of 10.0 units m2 or less. Precise, accurate studies are mandatory in the evaluation of operability for the patient with complete transposition.

Results of Surgical Treatment for Congenital Aortic Stenosis

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.