A. Cournand

Catheterization of the Right Auricle in Man

Forssmann 1 first used catheterization of the right heart on himself, after exposure of a vein of the arm by a surgeon. Numerous other investigators since have used right heart catheterization for visualization of the right chamber of the heart and pulmonary vascular trees by means of contrast substance. 2 3 4 5 6 7 The introduction of the Robb and Steinberg method, 8 however, renders this method unnecessary for the latter purpose. Collection of right heart blood by catheterization of the right auricle for determining cardiac output in man 9 is mentioned by Grollman, 10 who discredits it because of the possible dangers and numerous misleading factors associated with it. In animal experimentation it is widely used and its innocuity established. Because it is apparently the soundest method for obtaining mixed venous blood for respiratory gas determinations, and because of the numerous problems of hemodynamics it might help solve, a method of right heart catheterization was developed which attempts to overcome objections to former methods. The principal objections included the possibility of venous thrombi and thrombophlebitis that might be associated with introduction of a foreign body in the blood stream, the formation of thrombi within the catheter, and the psychic effects accompanying the procedure with possible alterations in the cardiac output. The following equipment was used in our method: a specially made 10 gauge Lindeman type of needle; a 3-way stopcock with a Luer lock, tightly fitting adapter; a No. 8 French flexible radiopaque ureteral catheter with 2 holes, one at the rounded tip and another about 1 cm from the tip. The catheter is silk with a smooth varnish finish. A saline reservoir with rubber tubing and clamp for controlling the rate of flow was also used. Under the strictest asepsis a nick is made in the skin over the median basilic vein of either the right or left arm after a preliminary infiltration with 2% novocain.

The Fourth Walter Wile Hamburger Memorial Lecture, Institute of Medicine of Chicago Some Aspects of the Pulmonary Circulation in Normal Man and in Chronic Cardiopulmonary Diseases

A review of present day knowledge of the pulmonary circulation in man is presented. In particular the state of the lesser circulation in normal man at rest and under conditions of exercise and acute anoxia is defined in detail in order to provide the physiologic background against which to present the accumulated data in patients with certain types of chronic cardiopulmonary diseases.

Time Relationship of Dynamic Events in the Cardiac Chambers, Pulmonary Artery and Aorta in Man

Exposure of the heart in the course of chest surgery affords a means of faithfully recording pressure pulses in the four chambers of the heart and in the large vessels of human subjects. This study in 13 individuals without any clinical evidence of cardiovascular disease, is concerned with the time relationship between electric and mechanical events and with the temporal sequence and respective characteristics of similar phases of the cardiac cycle in both sides of the heart. The results obtained by permutation of simultaneous pressure recordings confirm the classical observations made in dogs.

Some Effects of Digoxin upon the Heart and Circulation in Man Digoxin in Chronic Cor Pulmonale

The effects of acute digitalization upon the dynamics of the circulation were observed in patients with chronic cor pulmonale, using the technic of cardiac catheterization. The state of the circulation was further investigated in the same patients following recovery from failure. The mode of action of intravenous digoxin is discussed, and a tentative concept of the pathogenesis of chronic cor pulmonale is presented.

Influence of chronic pulmonary disease on the heart and circulation

Abstract 1.1. Studies of both cardiac and pulmonary function were made in forty-eight cases of chronic pulmonary disease. The pathogenesis of pulmonary hypertension and the evolution of chronic cor pulmonale have been considered. 2.2. Pulmonary arterial hypertension was present at rest in thirty-nine of the forty-eight patients studied. 3.3. In chronic pulmonary emphysema anoxia was shown to be the important abnormality since it was directly or indirectly responsible for the circulatory complications found in these patients. The reversible nature of these circulatory complications in emphysema was demonstrated and its importance with regard to therapy was stressed. It would appear that in patients with chronic cor pulmonale and emphysema cardiac failure is generally characterized by a high cardiac output. 4.4. In patients with silicosis and emphysema the pulmonary hypertension is less likely to be reversible since it stems from anatomic alterations in the pulmonary vascular bed rather than from anoxia. When chronic cor pulmonale and cardiac failure develop in this type of patient, the cardiac output is not elevated. This emphasizes the point that chronic cor pulmonale in failure is not always of the high output type. 5.5. The circulatory changes found in the group of patients with diffusion fibrosis do not appear to be related to anoxia but probably spring from the anatomic lesions produced by the disease processes themselves.

STUDIES ON INTRAPULMONARY MIXTURE OF GASES. IV. THE SIGNIFICANCE OF THE PULMONARY EMPTYING RATE AND A SIMPLIFIED OPEN CIRCUIT MEASUREMENT OF RESIDUAL AIR

In preceding papers of this series, we have studied (1) the relative effectiveness of mixing or distribution of tidal air into alveolar spaces in normal and abnormal subjects, and have proposed (2) an open circuit method for residual air determination, in which nitrogen in the lungs is washed out by continuous inhalation of pure oxygen. The present paper (a) gives the results of a number of determinations of residual air, by the open circuit method, in normal subjects and patients with chronic cardiac or chronic pulmonary disease; (b) offers certain simplifications of technique in the open circuit method; and (c) suggests further significance of some of the data which this method provides. It will simplify the succeeding discussion if a brief review is given of the theoretical basis of the open circuit method of residual air determination. The principle underlying all residual air methods which employ an inert gas, such as nitrogen or hydrogen, is the measurement of this inert gas before and after its distribution (by means of a period of breathing) between an unknown volume (the lungs) and a known volume (the spirometer). The relationship is described by a simple formula. Let nitrogen be the inert gas measured: (Nitrogen percentage in lungs at start X lung volume) + (nitrogen percentage in spirometer at start X spirometer volume) (nitrogen percentage in lungs at end X lung volume) + (nitrogen percentage in spirometer at end X spirometer volume). For purposes of simplification, the correction factor due to nitrogen excreted from the body (3) is here disregarded. Solving the above equation for lung volume,

Mechanical and Myocardial Factors in Rheumatic Heart Disease with Mitral Stenosis

Sixteen patients with rheumatic heart disease and pure mitral stenosis, studied by cardiac catheterization, are presented to illustrate the relative importance of mitral block and myocardial insufficiency in this disease. Analysis of hemodynamic data permitted a separation of those patients with predominantly mechanical mitral block from those in whom myocardial insufficiency appeared to be the predominant lesion. The importance of recognizing the existence of the latter group is emphasized, since commissurotomy will not be of benefit in such cases.

Pure congenital pulmonary stenosis and idiopathic congenital dilatation of the pulmonary artery

Abstract 1.1. Sixty-eight cases of pure congenital pulmonary stenosis without abnormal shunts, the diagnosis established at autopsy, have been collected from the literature and the chief clinical and anatomic features are described. 2.2. Eight cases of pure congenital dilatation of the pulmonary artery have been selected from the literature of the last thirty years as being unequivocal examples of that lesion and a summary of the clinical and anatomic features is given. 3.3. Four additional examples of each of these lesions are reported. 4.4. Hemodynamic studies of these eight patients demonstrate the absence of abnormal shunts and the presence of a differential between the systolic pressure in the pulmonary artery and that in the right ventricle. 5.5. A division of these patients into two groups on the basis of the pressure in the right ventricle and the intensity of the pulmonic second sound is proposed. ∗

THE EFFICIENCY OF VENTILATION DURING VOLUNTARY HYPERPNEA: STUDIES IN NORMAL SUBJECTS AND IN DYSPNEIC PATIENTS WITH EITHER CHRONIC PULMONARY EMPHYSEMA OR OBESITY

The ventilatory apparatus is analogous to a mechanical system composed of an engine coupled to a pump. The engine comprises the chest wall and the diaphragm, while the pump embraces the airways and the lungs. Although the two units operate as a single assembly, their functions are distinct. The engine converts metabolic energy into mechanical work; the pump translates this work into a rhythmic exchange of air. According to this schema, the useful work of the chest wall and diaphragm is that performed on the surfaces of the lungs. Hence, the efficiency with which this work is accomplished is defined by the formula written below.

Effects of Acute Hypoxia and Exercise on the Pulmonary Circulation

The effects of acute hypoxia, of graded exercise, or both, on the pulmonary circulation were studied in 17 normal subjects. In 3 of these subjects, and in 3 patients with restricted vascular beds, the effects of these stimuli were compared during successive test periods. In 7 normal subjects, moderate exercise, associated with an increase in cardiac output of approximately 25 per cent, resulted in an average rise in pulmonary arterial mean pressure of 3 mm.Hg. More strenuous exercise in the same subjects, associated with a further increase in cardiac output of approximately 25 per cent, did not elicit further increment in pulmonary arterial mean pressure. In contrast, 10 subjects with normal pulmonary circulations, who responded to acute hypoxia with an average reduction of arterial oxygen saturation of 17 per cent, manifested an average increase in cardiac output of 5 per cent and an average rise in mean pulmonary arterial pressure of 4 mm.Hg. The critical level of arterial blood oxygen saturation for a significant rise in pulmonary arterial pressure was 85 per cent: in 6 subjects, with arterial blood O2 saturation reduced below this level, the average pulmonary artery pressure rise was 7 mm. Hg. In the 3 subjects with normal pulmonary circulations who performed exercise and were exposed to acute hypoxia, the contrasting effects of these stimuli on the pulmonary circulation were striking. In the 3 patients with restricted vascular beds exposed successively to both stimuli, the rise in pulmonary arterial mean pressure appeared to be linearly related to the increase in pulmonary blood flow. In 1 subject, the surgical resection of the preganglionic fibers and ganglia which supply sympathetic efferent nerves to the pulmonary vascular tree was without effect on the responses of the pulmonary circulation to acute hypoxia and to exercise. The present study failed to identify the mechanism and the site of action of acute hypoxia on the pulmonary circulation.