Bernard H. Pastor

Effect on cardiac output of conversion from atrial fibrillation to normal sinus mechanism

Abstract Hemodynamic studies were performed before and after restoration of a normal sinus rhythm in forty-eight patients with chronic atrial fibrillation. Conversion to a sinus mechanism was achieved in twenty-six patients with quinidine and in twenty-two patients with capacitor discharged direct current. In the quinidine-treated group, who were restudied five to ten days after conversion, the mean cardiac index had risen 22 per cent from 2.40 to 2.93 L., the circulation time had decreased from a mean of 17 to 12 seconds, the mean stroke volume had increased 44 per cent from 55 to 79 ml. and the mean arteriovenous oxygen difference had dropped from 5.4 to 4.3 cc. per 100 ml. In the electrically treated group, who were studied serially for 3 hours after conversion, there was a gradual 12 per cent rise in cardiac index from a preconversion mean of 2.36 to 2.65 L. 180 minutes later, accompanied by commensurate improvement in the other hemodynamic parameters. Our data confirm the experimental studies reported in lower animals and man which indicate that a normally positioned atrial systole contributes importantly to ventricular function since restoration of a normal sinus mechanism in patients with chronic atrial fibrillation is followed by a significant increase in cardiac output. The full hemodynamic benefit, however, may not be evident for several hours or days after the return of normal electrical atrial activity.

Reversible Nephrotic Syndrome Resulting from Constrictive Pericarditis

THE clinical concept of the nephrotic syndrome, a state characterized by edema, proteinuria and hypoproteinemia, has been extended from its classic application to a few renal diseases classified as...

Dissecting Aneurysm of the Aorta Secondary to Tuberculous Aortitis

Tuberculous aortitis is rare, only 29 cases having previously been reported. The first known case of dissecting aneurysm of the aorta secondary to tuberculous aortitis is described. The site of dissection was in the adventitia instead of the usual location in the media. The possibility of gradual aortic dissection without the classical acute picture is emphasized.

Hypertension associated with renal artery aneurysm and relieved by nephrectomy.

Excerpt INTRODUCTION Well documented examples of hypertension produced by unilateral renal lesions are relatively rare. The importance of recognizing such lesions is obvious, since this form of hyp...

The hemodynamic effects of digitalis in the normal and diseased heart

Abstract Concepts of the hemodynamic action of digitalis have changed greatly during the past 50 years, and recent developments suggest that we may reasonably anticipate further evolution of these ideas. Present experimental and clinical observations can best be reconciled with the hypothesis that digitalis exerts a positive inotropic effect on all types of muscle, smooth and voluntary as well as cardiac. Indirect cardiac effects result from its action on arterial smooth muscle and on venous smooth muscle, primarily of the hepatic veins, by altering blood pressure and cardiac inflow. The direct cardiac action results in increased force of systolic contraction, with a resultant increase in cardiac output. These effects appear to be the same in normal or diseased hearts, although their external effects in terms of cardiac output may differ. The prevalent idea that digitalis is detrimental to the nonfailing heart is not compatible with our present knowledge of its pharmacologic properties. In addition to its therapeutic use in cardiac failure of any etiology, it can, therefore, also be used “prophylactically” in patients about to undergo stress, such as surgery or delivery, if there is any reason to suspect impaired myocardial reserve. It also plays an important role in the prevention and treatment of arrhythmias by virtue of its salutary effect on the functioning of cardiac muscle.

A comparison of laboratory methods for the control of anticoagulant therapy with prothrombinopenic agents: I. The Quick one-stage procedure, the prothrombin and proconvertin test and the one-stage determination of true prothrombin activity

Abstract Several newer, more complex tests of the clotting mechanism have been suggested to replace the relatively simple Quick one-stage test for prothrombin complex activity. In a controlled study of the P and P test, the one-stage determination of true prothrombin activity and the Quick one-stage test using two commercially available tissue thromboplastins, neither of the more complex procedures was shown to be superior to the Quick procedure. Because of the intermediate sensitivity of the Quick test, patients whose prothrombin complex activity values were controlled with it most often had values in the therapeutic range of the other two tests as well. The Quick one-stage procedure, properly performed, appears to be a satisfactory method for the control of anticoagulant therapy in the light of our incomplete knowledge of anticoagulant mechanisms.

Pericardial Calcification associated with Histoplasmosis.

HISTOPLASMOSIS is known to involve many tissues, but pericardial involvement has rarely been reported. Since histoplasmosis is a generalized infection of the reticuloendothelial system, with prolif...

II. Problems encountered in the laboratory control of anticoagulant therapy with the one-stage determination of prothrombin complex activity

Abstract An evaluation of the Quick one-stage determination of prothrombin complex activity was undertaken to determine why it has not been entirely satisfactory in clinical practice, and whether its deficiencies can be corrected. Our results indicate that the test is relatively simple, accurate and, except for prolonged exposure of plasma and reagents to water bath temperatures, not seriously affected by common variations in technic. The chief source of error in clinical laboratories appears to be the use of incorrect dilution curves for conversion of plasma clotting time to per cent of normal plasma activity. This difficulty is compounded by the controversy regarding the proper choice of a diluent in making these curves. Until laboratory personnel agree to use the same highly standardized thromboplastin preparation for the test and the same diluent in constructing dilution curves, conversion to per cent of normal plasma activity will not provide a satisfactory basis for comparison of results from different laboratories, and the results are better expressed in seconds. With attention to standardization of technic the one-stage determination of prothrombin, complex activity is a satisfactory method for the control of anticoagulant therapy with coumarin-like agents.

A comparative study of four prothrombinopenic anticoagulant drugs: II. Clinical study

Abstract Four prothrombinopenic anticoagulants were compared under controlled conditions in 287 patients over a LAperiod of fourteen months. Somewhat better control was achieved with bishydroxycoumarin and diphenadione than with phenindione and warfarin. The differences were statistically significant but not great. Satisfactory control was achieved in the majority of patients with all four drugs. There was relatively wide variation in dosage requirements in the same patient from day to day and among patients receiving the same preparation. This variation was less with bishydroxycoumarin and diphenadione than with phenindione and warfarin, but the differences were not sufficient to be clinically useful. An induction schedule which consisted of a large single loading dose followed by a small maintenance dose was found to be desirable and safe. Using such a program the prothrombin activity in the majority of patients (82 per cent) was brought into the therapeutic range within forty hours of the initial dose with all four drugs. This program also facilitated the early establishment of a stable maintenance dose.

Persistent left superior vena cava demonstrated by angiocardiography

Abstract A persistent left superior vena cava was demonstrated by angiocardiography during the preoperative evaluation of a patient with aortic stenosis for valvular surgery. This rare anomaly produces no physiologic disturbance unless there are associated malformations, or unless the anomalous vein enters the left atrium. It may, however, interfere with successful cardiac catheterization, produce obstruction at the time of cardiac surgery, or call attention to the presence of other congenital malformations.