Russell V. Lucas

Anomalous Muscle Bundle of the Right Ventricle Hemodynamic Consequences and Surgical Considerations

Seven examples of anomalous muscle bundles of the right ventricle have been presented. In one patient having an associated ventricular septal defect, spaces between the anomalous muscle were confused surgically with the ventricular septal defect. In the remaining six cases, the anomalous muscle bundle caused obstruction within the right ventricular cavity. Five of these patients had associated ventricular septal defect, with a clinical picture resembling that of the cyanotic or acyanotic tetralogy of Fallot. The cases served to demonstrate that the surgeon who exposes the right ventricle to relieve an obstructive lesion in the right ventricular infundibulum or in the pulmonary valve, may find no such lesions in these locations but instead may be dealing with an obstruction more proximal than these areas. Relief of the obstruction within the right ventricle may be attained by resecting the anomalous muscle mass. In one patient having intact ventricular septum and pulmonary valvular stenosis, an anomalous muscle bundle within the right ventricle which lay proximal to the infundibulum was responsible for persistent right ventricular obstruction after pulmonary valvotomy. Anomalous muscle bundles in the right ventricle may be suspected when, in the angiocardiogram, they cause filling defects within the right ventricle.

ENDOCARDIAL FIBROELASTOSIS. A CLINICAL AND ANATOMIC STUDY OF 47 PATIENTS WITH EMPHASIS ON ITS RELATIONSHIP TO MITRAL INSUFFICIENCY.

A clinical and pathologic study of 47 cases with endocardial fibroelastosis is presented. These cases have been classified according to the associated cardiac anomaly and the anatomic condition of the left ventricle. In so doing, a better understanding is had of the role the cardiac anomaly associated with endocardial fibroelastosis plays in the production of cardiac signs and symptoms.In each of the specimens available for review, a change of the mitral valve was present that rendered it insufficient. Those cases grouped as primary endocardial fibro-elastosis had this as the only abnormality present, other than the endocardial fibroelastosis. Many of the clinical and laboratory findings in this group could be explained on the basis of mitral insufficiency, and one cannot necessarily assign the cardiac signs and symptoms to the endocardial process itself. In those cases with associated cardiac anomalies the hemodynamic consequences appear to be a summation of the combined effects of the mitral insufficiency, endocardial fibroelastosis, and the associated cardiac anomaly.In this review, we were unable to distinguish, by either gross or microscopic methods, between primary and secondary endocardial fibroelastosis. Since use of these terms suggests etiologic relations, it is preferable to classify cases of endocardial fibroelastosis on the basis of the structural abnormalities present.

The Natural History of Isolated Ventricular Septal Defect A Serial Physiologic Study

Forty patients with isolated ventricular septal defect were studied physiologically two or more times before they underwent surgical treatment. Utilizing baselines obtained by heart catheterizations of normal infants and children, we grouped patients with ventricular septal defect according to the magnitude of the total pulmonary resistance, pulmonary blood flow, and pulmonary arterial pressure, and according to changes in these values over time. The patients with small defects (less than 1 cm. per M.2 of body surface area) were easily separable on the basis of physiologic findings. Patients with large ventricular septal defects (greater than 1 cm. per M.2 of body surface area) exhibited one of three possible initial responses to the stress of high pulsatile pulmonary flow and increased pulmonary artery pressure: (1) normal regression of total pulmonary resistance; (2) delayed fall in total pulmonary resistance; (3) failure of the total pulmonary resistance to decrease with age. These physiologic responses were thought to be related to normal maturation, delayed maturation, or failure of maturation of the pulmonary vascular bed. It was observed that a subsequent increase in total pulmonary resistance could be superimposed on any of the three initial responses at any time. Clinical evidence and catheterization data suggested that the relative size of the ventricular septal defect had decreased in five patients. The variability of the physiologic courses, the importance of the pulmonary vascular bed in determining these responses, and our lack of understanding of the etiology of the pulmonary vascular changes were noted. The indications for, and timing of surgical intervention in patients with isolated ventricular septal defects, are discussed in light of the above findings.

Direct communication of a pulmonary artery with the left atrium. An unusual variant of pulmonary arteriovenous fistula.

Direct communication of a pulmonary artery with the left atrium is described and considered a variant of pulmonary arteriovenous fistula. A 3-year-old girl presented with clinical evidence of a lesion of the central nervous system. The history revealed that she had been cyanotic and had had clubbing of the digits and polycythemia. A rounded mass was noted in the region of the right pulmonary hilus in the posteroanterior thoracic roentgenogram. A pulmonary arteriovenous fistula was suspected, but the patient succumbed with a cerebral abscess before definitive diagnostic studies and therapy were undertaken. Anatomic examination revealed an unusual variant of pulmonary arteriovenous fistula, namely, direct communication of the right lower pulmonary artery with the left atrium and absence of the middle and lower lobes of the right lung. It is important that pulmonary arteriovenous fistulas be suspected clinically, since definitive diagnosis and therapy are now possible. While the hemodynamic effects of this type of lesion are usually not severe, untreated patients suffer a high morbidity and mortality through systemic arterial oxygen desaturation, paradoxic embolization, cerebral abscess, and rupture of the fistula.

Symptomatic Atrial Septal Defect in Infancy

Atrial septal defect of the ostium secundum variety (ASD) is uncommonly diagnosed in infancy and rarely results in congestive heart failure (CHF). Eleven patients with uncomplicated ASD who developed CHF between 6 days and 13 months of age are presented.The diagnosis of ASD was documented by cardiac catheterization in all 11 patients. Left-to-right shunt ranged from 52 to 80%. Right ventricular pressure was near systemic levels in two patients and at least somewhat elevated in the other nine. Total pulmonary resistance (TPR) was within normal limits in all 11. No left ventricular obstructive lesions were found. Although one patient had unusual thickening of the left ventricular myocardium, and the left ventricular cavity was enlarged in two other cases, no specific abnormality in left or right ventricular function could be defined.Spontaneous closure of the ASD did not occur in any of our patients. Since spontaneous closure even of a large ASD can occur, however, it seems advisable to defer elective surgical closure until after 2 years of age if successful medical management can be achieved. In those patients in whom early surgery is not necessary, the clinical course usually becomes that of a typical ASD by age 2 years.

Pre- and postoperative rest and exercise hemodynamics in children with pulmonary stenosis.

Twenty children with pulmonary valvular stenosis were studied by cardiac catheterization both at rest and during submaximal supine exercise, prior to and following pulmonary valvotomy. The resting and exercise states were comparable preoperatively and postoperatively since cardiac output, heart rate, A - V O2 difference and oxygen consumption were similar. Evidence of improved cardiac function was found postoperatively.Both the rest and the exercise right ventricular end-diastolic pressure (RVEDP) decreased significantly following pulmonary valvotomy. Preoperatively, 12 of 20 patients showed an increase in RVEDP with exercise; in six of these there was a simultaneous fall in stroke index, indicating impaired myocardial function. No patient showed this response postoperatively.This indicates that although altered cardiac function can be demonstrated in some children with pulmonary valvular stenosis, it is reversible by pulmonary valvotomy. This is in contrast to studies in adults, and suggests that a factor in the natural history of pulmonary valvular stenosis is the impact of chronically elevated afterload on the right ventricle. Hemodynamic measurements made during exercise provide a useful means of assessing patients with pulmonary stenosis before and after pulmonary valvotomy.

Exercise Hemodynamics of Pulmonary Valvular Stenosis: Study of 64 Children

Sixty-four children with pulmonary stenosis were studied by cardiac catheterization both at rest and on exercise. Whereas milder degrees of stenosis were associated with normal right ventricular function, more severe stenosis was associated with fixed stroke index and elevated RVEDP, and suboptimal response of cardiac index. These changes result from altered right ventricular compliance. In several the compliance abnormality was related to myocardial hypertrophy, whereas in four patients it was most likely caused by myocardial fibrosis.

A Developmental Complex Including Supravalvular Stenosis of the Aorta and Pulmonary Trunk

A developmental complex is described characterized by (1) supravalvular stenosis of the aorta and pulmonary trunk, (2) dysplasia of valves and (3) stenosis of ostia of coronary arteries and branches of the aortic arch. From the four cases described, it is evident that not all of the features of the complex need be present in a given case and, when present, some lesions are not of functional significance. The variations underly the potential for differences in the hemodynamic states of affected subjects.

Taussig-Bing Malformation, Coarctation of the Aorta, and Reversed Patent Ductus Arteriosus Operative Correction in an Infant

Operative correction of a Taussig-Bing malformation was successfully accomplished in a 23-mo-old boy, weighing 6.8 kg. Associated coarctation of the aorta and reversed patent ductus arteriosus were corrected in a preliminary operation. The patients management was complicated by severe preoperative thrombocytopenia which responded to multiple phlebotomies. Surgical repair of the Taussig-Bing malformation consisted in patching the ventricular septal defect to create physiologically complete transposition of great vessels. Then a Mustard procedure was done.

The symmetrical liver as a roentgen sign of asplenia.

THE YOUNG INFANT with cyanotic congenital cardiac disease presents an acute and difficult diagnostic problem. The anomalies responsible for eyanosis in some such infants are now curable surgically while, on the other hand, there remains a group of eyanotic newborn infants in whom the congenital cardiac anomalies are so complex that no surgical procedures for their correction have yet been devised. A method for early separation of these two groups of patients, that is, operable and inoperable, would be of value. Among the so-called inoperable group of patients are individuals with asplenia and congenital cardiac disease, since in these the cardiac anomalies are of such a complex nature that they usually defy surgical correction. Among a group of cases of asplenia with congenital cardiac diseases the pathologic manifestations include persistent truncus arteriosus, transposition of the great vessels, pulmonary atresia or stenosis, common atrioventricular canal, anomalies of pulmonary veins, and cor biloculare. Moreover, several of these complex malformations usually coexist in the same patient. Visceral symmetry is common also. One step in the direction of separating by clinical means the operable from the inoperable group is to determine whether the spleen is absent. Evidence favoring asplenia includes certain changes in the peripheral blood and findings of visceral symmetry.