Sidney M. Fierst

Resting blood flow and peripheral vascular responses in hypertensive subjects

Abstract 1. 1. The rate of resting blood flow was studied in a series of seventy hypertensive and ninety normal subjects by means of the venous occlusion plethysmographic method. 2. 2. It was found that in the hypertensive patients the resting blood flow in the forearm and leg was significantly greater than that in the normal group. 3. 3. In the hand, however, the average blood flow was much less in the hypertensive than in the control subjects. 4. 4. The fact that the blood vessels in the hand are under the control of the vasomotor center, whereas those in the forearm and leg are little, if at all, affected by vasoconstrictor impulses, was considered significant in this respect. 5. 5. A period of local anoxemia was found to elicit a response of equal magnitude in both the hypertensive and the normal subject. 6. 6. Similarly, the blood flow repayment after a specified amount of work was the same in the two groups. 7. 7. Evidence was obtained which suggested that the venous bed in the extremities in hypertension is in a state of normal tonus.

Resting peripheral blood flow in the anemic state

Abstract By means of the venous occlusion plethysmographic method, the peripheral circulation was investigated in a series of eleven patients with anemia of various types. A moderate increase in blood flow was observed in the forearm, but in the hand the readings were, for the most part, within the lower range of normal or somewhat decreased. The observations on the forearm constitute direct confirmation of the view that one of the compensatory mechanisms elicited in the anemic state is an augmented circulation through the tissues.

Evaluation of the local vasodilator effect of acetyl-beta-methylcholine chloride (mecholyl) by iontophoresis☆

Abstract 1. 1. The vasodilating action of mecholyl by iontophoresis was studied in the forearm, leg, and foot of nine normal subjects by means of the venous occlusion plethysmographic method. 2. 2. It was found that this procedure immediately produced a significant increase in the rate of blood flow in the forearm and foot, which continued for some time after the treatment was terminated. The effect upon the leg was less marked. 3. 3. The increase in flow was considered to be primarily the result of vasodilatation of cutaneous blood vessels, those in the muscles probably contributing little if at all to the effect.

EFFECT OF MUSCULAR EXERCISE UPON THE PERIPHERAL CIRCULATION IN PATIENTS WITH VALVULAR HEART DISEASE

Considerable controversy still exists as to the hemodynamics associated with organic involvement of the valves of the heart in man. With respect to aortic insufficiency, Stewart (1), mainly on the basis of animal experiments, advanced the view that the collapsing pulse in this state is due to an increased blood flow through the capillaries following reflex inhibition of the vasomotor center, and not to regurgitation into the left ventricle. Hill and Rowlands (2), in order explain the apparently greater blood pressure in the lower extremities as compared with that in the arms, postulated that the leg arteries are held in a contracted state, so that the brain might receive a sufficient supply of blood. However, Gladstone (3), also on theoretical grounds, came to the opposite conclusion, that the average rate of flow to the hand, arms, and kidneys is less than normal, while the legs receive a disproportionately large share of the total output of the heart. In relation to the problem of hemodynamics in mitral stenosis, the experimenttl work has for the most part consisted of cardiac output studies. The results, however, have been contradictory, some of the investigators (4, 5) observing a decreased, and others (6, 7), a normal minute volume output in this state. With respect to the peripheral circulation, Meakins and his associates (4) reported a diminished oxygen saturation and an increased carbon dioxide content of venous blood from the arm. On the basis of these findings, they concluded that in this state the resting muscles in the extremities are partially deprived of their normal complement of arterial blood, in order that more essential organs might obtain an adequate supply of oxygen. According to them, some of the general symptoms observed in patients with mitral stenosis, such as cyanosis, weakness, and fatigue, are reflections of the diminished rate of peripheral blood flow. Stewart and his collaborators (8) studied the arm-to-tongue circula-

Resting Blood Flow in the Extremities in Hyperthyroid Subjects.

Conclusion The rate of blood flow through the forearm is increased in hyperthyroidism.