Walter T. Goodale

Studies of Congenital Heart Disease IV. Uncomplicated Pulmonic Stenosis

Congenital pulmonic stenosis is indicated by cardiac catheterization by the finding of a higher systolic pressure in the right ventricle than in the pulmonary artery. Eight cases of uncomplicated pulmonic stenosis are studied. The findings on history, physical examination, x-ray and fluoroscopy, and electrocardiogram have been analyzed and the variations in circulatory dynamics encountered in these individuals are described in detail.

Studies of the circulatory dynamics in mitral stenosis. II: Altered dynamics at rest

Abstract 1. 1. Twenty-one patients with mitral stenosis have been studied by the technique of cardiac catheterization. These patients were classified clinically and also according to the size of the orifice of the mitral valve. Six patients were in pulmonary edema during the study. 2. 2. As a consequence of mitral valvular stenosis, a balance develops between pulmonary vascular pressures and peripheral blood flow (tending toward an increase in pulmonary pressure and a decrease in blood flow). 3. 3. Cardiac and stroke indices were decreased at rest, although a wide range of values was seen. Patients with auricular fibrillation had slightly lower cardiac indices than patients with normal sinus rhythm. Tissue oxygen extraction per cubic centimeter of blood was increased so that oxygen consumption was maintained within the normal range in all. 4. 4. Pulmonary “capillary” pressures were increased above normal as a result of the increase in left atrial pressure proximal to the mitral stenosis. 5. 5. Pulmonary arterial pressures were increased above normal as a result of (a) the increase in pulmonary “capillary” pressure and (b) increased pulmonary arteriolar resistance. 6. 6. The presence of an elevated pulmonary arteriolar resistance was roughly related to the level of pulmonary “capillary” pressure and the degree of valvular stenosis. 7. 7. An inverse logarithmic relationship was observed between total pulmonary resistance and stroke output per square meter. 8. 8. As a result of the increased pulmonary vascular pressures, the pressure work of the right ventricle was greatly increased. 9. 9. Right ventricular incompetency, as judged by an elevated filling pressure, was seen in over one-half of the patients studied. Incompetence was believed due to (a) the increased pulmonary pressure load and (b) underlying myocardial damage from rheumatic fever.

Effects of exercise on circulatory dynamics in mitral stenosis. III.

Abstract 1. 1. Eight patients with mitral stenosis have been studied at rest and during exercise by the technique of cardiac catheterization. Three of the patients developed pulmonary edema on exercise. 2. 2. The resting balance between pulmonary pressure and peripheral blood flow was upset by exercise. The imbalance was related not only to the degree of stenosis but to the ability of the circulation to increase the cardiac output. 3. 3. Except for two patients with mild mitral stenosis, cardiac index failed to rise in normal fashion on exercise. Stroke index on the average did not change with exercise, although both increased and decreased stroke outputs were seen, depending on the pulse rate and diastolic filling period. Tissue oxygen extraction per cubic centimeter increased markedly on exercise. 4. 4. Pulmonary “capillary” pressure rose on exercise in association with increases in rate of mitral valvular blood flow. 5. 5. Pulmonary arterial pressure rose on exercise in association with the increase in pulmonary “capillary” pressure and in some cases with the increase in blood velocity flow. 6. 6. Pulmonary arteriolar resistance showed no consistent change on exercise, the average values at rest and during exercise being almost identical. 7. 7. Right ventricular work against pressure, already elevated at rest in most of the patients, became even greater on exercise. 8. 8. Almost all patients had elevated right atrial mean pressures at rest. Further rises occurred in two of the four in whom right atrial pressure was measured on exercise.

Myocardial Carbohydrate Metabolism in Normal Dogs, with Effects of Hyperglycemia and Starvation

Myocardial metabolism of Nembutalized normal intact dogs was studied with the aid of the coronary sinus catheterization technic. Oxygen, glucose, lactate and pyruvate were extracted by the heart in direct relation to the arterial level of each substance, independently of the others. Pyruvate and lactate showed a high myocarcdial extraction coefficient, but the normal low arterial levels at rest prevented them from together accounting for more than 50 per cent of the total myocardial energy requirements. Glucose was not utilized below a mean threshold of 54 mg. per cent, but with normal arterial levels of 70 to 120 mg. per cent, glucose extraction was sufficient to provide the major potential source of fuel for myocardial oxidative energy. During starvation, the heart probably derived its energy from fat, as indicated by a myocardial respiratory quotient near 0.70, and a low myocardial carbohydrate extraction.

Measurement of Coronary Blood Flow in Dogs and Man from Rate of Myocardial Nitrous Oxide Desaturation

A technic of measuring left ventricular coronary blood flow in dogs and man from the rate of desaturation of nitrous oxide from the myocardium is presented. The desaturation technic appears valid in comparison with the previously described saturation technic, and affords definite technical advantages. By combining the two technics, flows may be measured within much less timethan by repeating either method alone.

The effects of fasting and diabetes mellitus on myocardial metabolism in man

Abstract 1.1. The normal human heart extracts glucose. lactate, pyruvate and oxygen in direct relation to the arterial blood level of each metabolite, independent of other factors. This phenomenon, which is shared with the dog, is best expressed by computing the myocardial extraction coefficient (A-V/A) for each metabolite. 2.2. Fasting in normal human subjects is accompanied by a decline in arterial blood levels of glucose, pyruvate, and lactate, and by a decreased myocardial extraction of carbohydrate substrate. The myocardial respiratory quotient averages 0.74, suggesting a major dependence upon fat for energy production. 3.3. In the postprandial state human subjects extract enough total carbohydrate to account for the entire oxygen consumption of the heart. The myocardial respiratory quotient is 0.90, which suggests, however, that some of the energy production of the heart is accounted for by fat under these conditions and that some of the extracted carbohydrate is used for non-oxidative purposes. 4.4. In fasting subjects with mild diabetes the myocardial glucose extraction was nil and the extraction of lactate and pyruvate markedly reduced despite increased arterial blood levels of glucose and normal levels of lactate and pyruvate. The myocardial respiratory quotient averaged 0.70, consistent with exclusive fat oxidation. 5.5. Administration of glucose or a meal to diabetic subjects resulted in markedly increased arterial blood glucose levels and some increase in myocardial extraction. Only simultaneous administration of insulin restored the myocardial extraction coefficients for glucose, pyruvate and lactate to normal.

Effects of Hemorrhagic Shock on the Heart and Circulation of Intact Dogs

The metabolic, hemodynamic and pathologic effects of hemorrhagic shock on the hearts of intact dogs have been studied, using the technique of venous catheterization of the coronary sinus. Metabolic studies demonstrated an alteration in the pattern of myocardial carbohydrate metabolism during shock and evidence for a relative myocardial oxygen deficiency. Subendocardial hemorrhage or necrosis was found in the left ventricles of some of the dogs.

Chronic constrictive pericarditis: Further consideration of the pathologic physiology of the disease

Abstract 1. 1. The methods of catheterization of the heart and the pulmonary vessels make it practical, for the first time, to investigate the pressure and flow phenomena in the right side of the heart and in the pulmonary vascular system of patients with constrictive pericarditis. Six such patients have been studied by these methods. 2. 2. Every patient showed an elevation of pulmonary “capillary” pressure (which reflects pulmonary venous pressure). This demonstration of pulmonary congestion is interpreted as indicating that involvement of the left ventricle plays a more important and sinister role in the functional changes associated with pericardial constriction than has been demonstrated previously. 3. 3. Every patient also showed an elevation of pressure in peripheral veins and in right atrium, and pressure measurements in the right ventricle and pulmonary artery which indicate a reduced ability of the right ventricle to contribute to the forward movement of blood. These observations confirm and emphasize the previously recognized involvement of the right ventricle. 4. 4. In every patient before operation the mean pulmonary capillary pressure was approximately equal to the peripheral venous pressure. 5. 5. No patient exhibited pressure changes pointing to physiologically significant obstruction in great veins or auricles. 6. 6. The limitation of stroke volume and cardiac output per minute in constrictive pericarditis previously demonstrated by other methods is confirmed by these studies. 7. 7. Consideration of the course of events after operation suggests that myocardial atrophy, myocardial fibrosis, and incomplete release of the ventricles may all play a role in the slow, and in most cases, incomplete return to normal dynamics after operation. 8. 8. The specific therapeutic implications of this study are: (A) the objective of surgery is the adequate release of both ventricles; (B) no indications have been found for the decortication of great veins or auricles, and (C) the early use of antibiotics in acute tuberculous pericarditis may minimize myocardial fibrosis and may permit operative treatment before myocardial atrophy is severe. 9. 9. Finally, the fact that improvement after operation is often slow and often incomplete in terms of objective measurement should not lead physicians to ignore the more important fact that a well-planned operation for constrictive pericarditis has in the past usually made the difference between invalidism and activity. The studies reported in this paper may be expected to make future operations for this disorder even more effective.

Graded reduction of arterial pressure in man by means of a thiophanium derivative (Ro 2-2222); preliminary observations on its effect in acute pulmonary edema.

The authors describe the use of a ganglionic blocking agent which acts almost entirely as a peripheral vasodilator with minimal side effects in man. This substance acts almost instantaneously when given intravenously, with the depressor effect quantitatively controlled by regulating the infusion rate without tachyphylaxis over several hours. Depressor effect of the drug disappears 2 to 15 minutes after stopping the infusion and is blocked promptly by intravenous ephedrine, neosynephrine or norepinephrine. The authors discuss its use in the treatment and elucidation of the basic mechanisms of acute pulmonary edema.

Pulmonary stenosis with intact ventricular septum; correlation of clinical and physiologic data, with review of operative results.

Abstract 1.1. Data on fifty patients with proved pulmonary stenosis and intact ventricular septum are presented. 2.2. The symptomatology is dominated by severe dyspnea and fatigue, and mild if any cyanosis. About 25 per cent of the patients have no symptoms. 3.3. The characteristic findings include a rough systolic murmur with a diminished second sound at the upper left sternal border, evidence of right ventricular hypertrophy in the electrocardiogram, and right ventricular enlargement, prominent main pulmonary artery and diminished pulmonary vasculature in roentgenograms. 4.4. Physiologic data reveal varying degrees of right ventricular hypertension and a systolic gradient across the pulmonary valve. The pressure tracings suggest the presence of a valvular stenosis in the majority of instances. Arterial unsaturation at rest always indicates severe stenosis and is found in about 10 per cent of the cases. 5.5. A significant correlation between the electrocardiographic findings of right ventricular hypertrophy and right ventricular systolic pressure could be established in this series. 6.6. Operative results in twenty-one patients subjected to Brock valvotomy are presented. There were three fatalities, all in patients exhibiting failure. All the survivors showed clinical improvement. In seven of eight patients studied by cardiac catheterization postoperatively, a satisfactory drop in right ventricular pressure was achieved. 7.7. A therapeutic classification is proposed: (a) Infants with severe stenosis in congestive failure should be operated on as soon as the diagnosis is made. (b) Patients with clinical findings suggesting right ventricular pressures of 100 mm. Hg or over usually should be operated upon at an appropriate time. (c) Patients in whom findings indicate that the right ventricular pressure is probably under 100 mm. Hg should be observed carefully but need not be subjected to cardiac catheterization or to operation.