John W. Kirklin

Relation between Structural Changes in the Small Pulmonary Arteries and the Immediate Reversibility of Pulmonary Hypertension Following Closure of Ventricular and Atrial Septal Defects

The relative importance of organic changes and vasoconstrictive influences in the production of increased pulmonary vascular resistance in congenital heart disease is problematic. With use of a grading system previously described, a study was made of the relation between each of the grades of hypertensive pulmonary vascular disease associated with ventricular or atrial septal defects and the change of pulmonary artery blood pressure immediately following closure of the abnormal communications. The immediate reversibility of the pulmonary hypertension varies inversely with the severity of the structural changes.

Heart Block after Repair of Ventricular Septal Defect in Children

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.

Atrial Septal Defect: Factors Affecting the Surgical Mortality Rate

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.

Anomalous Connection of Right Pulmonary Veins to Superior Vena Cava with Interatrial Communications Hemodynamic Data in Eight Cases

Anomalous connection of the right pulmonary veins to the superior vena cava associated with an interatrial communication in an unusually cephalad location has been diagnosed at cardiac catheterization in 8 patients. These patients had the clinical features seen in patients who have atrial septal defects in the region of the fossa ovalis. Differentiation was accomplished by (1) the roentgenographic position of the catheter in the right superior pulmonary vein, (2) demonstration of an abnormally high oxygen saturation of the blood in the superior vena cava, (3) the presence of a small right-to-left shunt from the superior vena cava and the absence of such a shunt from the inferior vena cava, and (4) demonstration of similar drainage of blood from the right superior pulmonary vein and superior vena cava. The syndrome is considered to be an anomaly of pulmonary venous development while the atrial septum forms normally.

Pulmonic Stenosis with Intact Ventricular Septum

Pulmonic stenosis unassociated with a ventricular septal defect of significant size is often a complex abnormality. The stenosis may be valvular, infundibular, or both, and may be associated with an atrial septal defect or even with a small ventricular septal defect. Preoperative studies cannot accurately predict these variations. The surgical approach selected for such patients should permit the correction of each of the cardiac defects encountered. That this can be accomplished by means of extracorporeal circulation and open cardiotomy is demonstrated by the presented series of 10 cases without operative mortality.

Differentiation of Interatrial Communications by Clinical Methods Ostium Secundum, Ostium Primum, Common Atrium, and Total Anomalous Pulmonary Venous Connection

Of 128 children with anatomically confirmed interatrial communications 74 had ostium secundum, 37 had ostium primum defects, 5 had common atrium, and 12 had total anomalous pulmonary venous connection. Analysis of the medical history, physical examination, roentgenogram, and electrocardiogram resulted in accurate diagnosis in most instances. In 6 of the 128 patients the proper diagnosis was not made: 3 infants with total anomalous pulmonary venous connection died within a few hours after admission to the hospital and did not have proper diagnostic evaluation; the condition of 3 other patients with ostium secundum defects was misdiagnosed as ostium primum defect before surgical treatment. In patients with ostium secundum and ostium primum defects the symptoms, signs, roentgenologic data, and findings at cardiac catheterization are similar, but differences in respect to the electrocardiograms are striking when the latter are subjected to vectorial analysis. The QRS loop is clockwise in the presence of ostium secundum defect and counterclockwise when ostium primum defect is at hand. Clinical and roentgenologic manifestations also are noted among patients with common atrium and total anomalous pulmonary venous connection, and the findings at cardiac catheterization likewise may be similar, but the electrocardiographic differences are significant. The QRS loop is counterclockwise in patients with common atrium and clockwise in patients with total anomalous pulmonary venous connection.

Pulmonary Vascular Resistance after Repair of Atrial Septal Defects in Patients with Pulmonary Hypertension

THE BEHAVIOR of the pulmionary vascular bed in congenital heart disease is a topic of major current initerest.1 3 The control of normal pulmoiary vessels remainis a matter for debate, in part because of difficulty in measurements and in the interpretation of the smnall differences in pressure across the normal pulmoniary vascular bed. Inl the presence of pulmioniary hypertenision, however, the responses of the pulmoniary vessels nmay be assessed with greater eertainty, since sizable pressure gradients frequenitly exist. Although a pulmonary arterial systolic pressure in excess of 30 iimm. Hg is outside the norinal range in this laboratory, the categorization of all patients with septal defects and pressures above this level as havinig pulmonary hypertension is of questionable value. Accordingly, we have adopted a pullnonlarv arterial systolic pressure of 60 mm. Hg as the most suitable compromise above which patients may be said to have significant pulmonary hypertension. Such a division serves to separate most patients with congenital heart disease in whom increased pulmonary arterial pressure contributes significantly to the totai problem from those in whom it does not. Classificationi on the basis of pulinonary vaseular resistance reimains the most important conceptual differentiation but suffers from the use of values that are indirect and open to far greater error than is the simple measurement of pulmonary arterial pressure. In atrial septal defects associated with pulmonary hypertension as just defined, the pulmonary vascular resistanee usually is in-

Selection for Surgery of Patients with Ventricular Septal Defect and Pulmonary Hypertension

Estimation of pulmonary blood flow relative to systemic blood flow is a critical point in selecting patients with ventricular septal defect and severe pulmonary hypertension for operation. A detailed medical history, physical examination, thoracic roentgenograms, careful interpretation of electrocardiograms, cardiac catheterization, and biopsy of the lung provide approaches to the problem. In borderline cases, decision still may be extremely difficult. The authors usually favor operation, however, with recognition that this decision may be in error. Obviously proper evaluation for operation cannot assure uniformly good results. Method of conduct of operation, perfusion, and postoperative care determine the results.

The electrocardiogram in children with ventricular septal defect and severe pulmonary hypertension. Correlation with response of pulmonary arterial pressure to surgical repair.

SUCCESS in the surgical treatment of children who have large ventricular septal defects is dependent in part on the proper selection of patients for operation. The patients most deser-ving of such correction are those who have severe pulmonary hypertension, and it is in these that the decision to offer surgical intervention may present the greatest problems. The factors influencing the increase in pulmonary arterial pressure deserve critical analysis. Elevated pulmonary arterial pressure in patients with large ventricular septal defects is, to a great extent, the result of 2 factors, namely increased pulmonary blood flow or increased pulmonary vascular resistance; both factors are present in some instances. -in those patients without pulmonary vascular disease but with a high pulmonary blood flow in relationship to systemic blood flow and witlh only slightly increased pulmonary vascular resistance, the pulmonary arterial pressure may be equal or nearly equal to the systemic pressure. In those who have complicating pulmonary vascular disease in whom the pulmonary resistance is increased and the pulmonary blood flow is not increased in relationship to systemic flow, the pulmonary and systemic pressures may be equal or nearly equal. If the increased pulmonary arterial pressure is prinmarily the result of increased pulmonary blood flow from a left-to-right shunt, surgical closure of the defect will result in a decrease in pulnmonary arterial pressure. If the in-

Volume of the left ventricle in tetralogy of Fallot.

Abstract Left ventricular volumes were measured by the angiocardiographic technic in 25 patients with tetralogy of Fallot, of whom 6 had a Potts or Blalock-Taussig anastomotic operation and 5 had complete repair of the defect. In 12 of the 14 patients who underwent no surgical procedure, the left ventricular volume was in the low normal range; the 2 others (with severe forms of tetralogy of Fallot) had significantly reduced end-diastolic volumes. In patients who had an anastomotic operation, the ventricular volumes were considerably increased if the left to right flow was large enough to cause symptoms; in the others they were in the normal range. Approximately two weeks after complete repair, the mean left ventricular volume was less than that for patients not operated upon. Significant aorticopulmonary collateral flow and some flow directly from the right to the left ventricle contribute to the normal volumes of the left ventricle in tetralogy of Fallot. Left ventricular myocardial function (as evidenced by ejection fraction) is significantly better after complete repair than it is in patients not operated upon or in patients treated by an anastomotic operation.