Citations

The response of the intra-arterial pressure to the cold immersion stimulus was studied in 42 healthy young adults, continuous direct (arterial-pressure) recording being used. The average systolic elevation was 22.6 mm. Hg and the average diastolic elevation was 16.3 mm. Hg. The difference between direct and indirect methods of measuring blood pressure was studied in 351 simultaneous determinations in 35 of these young adults. The direct systolic pressure averaged 9.7 mm. Hg higher and the diastolic pressure was 7.3 mm. Hg lower than the indirect measurement.

On the thoracic roentgenograms of patients with mitral stenosis, costophrenic septal lines are frequently seen. These lines are a sign of pulmonary venous hypertension. They were not seen in a representative group of patients with pulmonary arterial hypertension but without pulmonary venous hypertension.

The cold pressor test was performed three times at 15-minute intervals on 65 normotensive subjects and on 60 patients with essential hypertension both before and during treatment with antihypertensive drugs. The arterial pressure was recorded directly from the radial artery. On the basis of differences in the cold pressor response among individuals in the control group, the criteria for normal reaction and for hyperreaction were modified. The cold pressor response in the patients with essential hypertension was markedly depressed by the ganglionic blocking agents, but was not affected by various combinations of hydralazine, protoveratrine and reserpine.

Administration of a moderately large or large dose of cortisone to dogs having acute myocardial infarctions inhibited slightly the rate of removal of necrotic muscle fibers in these animals as compared with untreated animals. Delay was appreciable at four and six days after production of the infarct in animals receiving 2.5 mg. of cortisone per kilogram of body weight and at 4, 6, 12 and 21 days in animals receiving 10 mg. per kilogram. At all other periods up to essentially complete healing of the infarcts as defined at 60 days, no appreciable differences existed between treated and untreated animals.

The effect of hexamethonium on hypertension has been widely studied but its effect on the peripheral blood vessels of patients with severe occlusive vascular disease has been studied on only a few patients although the drug has been used empirically in the treatment of such disease. Observations were made on the effect of hexamethonium ion administered subcutaneously in increasing doses of 10 to 50 mg. on the skin temperature of the fingers and toes, the blood pressure and the pulse rates of a group of patients with severe arteriosclerosis obliterans. On this group of patients hexamethonium had little or no effect.

A correlation of the clinical and electrocardiographic findings was undertaken in 110 cases which had in common the presence of deeply inverted T waves in central terminal leads centered about position 3 on the precordium. The results of this study are reviewed. A summary is presented of changes encountered at the time of necropsy in nine cases in which electrocardiographic changes of similar type had been recorded. These observations are integrated with concepts derived from the dipole theory. The total evidence is viewed in relation to observations reported by other investigators.

Previous studies in this series demonstrated structural changes in the pulmonary vascular bed as the result of mitral valvular disease and other cardiac disorders. The present study demonstrates changes in the lungs as the result of chronic left ventricular failure; these changes were like those produced by mitral stenosis. The most pronounced disturbance was medial hypertrophy. The exact mechanism is not known, but it probably is related to increased pulmonary venous pressure.

Evidence is presented which indicates that shunting of small amounts of blood from right to left occurs frequently through interatrial communications. Such right-to-left shunts are of small magnitude in the usual case of atrial septal defect, but it appears that of the fractions of blood shunted, a greater proportion has originated from the inferior vena cava than from the superior vena cava.