Acute and Chronic Cardiovascular Effects of Pentolinium in Hypertensive Patients

Abstract

Using a tracer injection technic, modified to provide accurate and repeated determinations of cardiac output in the ambulatory patient, the authors have shown that chronic pentolinium therapy for hypertension lowers blood pressure by reducing cardiac output in the seated position. From these observations and the work of others, they believe that the effect of ganglionic blockade on venoconstrictor tone deserves greater emphasis.D ESPITE the widely accepted use of ganglionic-blocking agents in the treatment of severe hypertension, surprisingly little is known of the mechanism whereby the blood pressure is reduced in the ambulatory patient. In particular, it has not been possible heretofore to make repeated observations of the effect of these agents on the cardiac output in the orthostatic hypertensive patient before and at various time intervals following initiation of treatment. This report deals with certain modifications of the dye injection method for cardiac output, which permits such repeated examinations, and is, to our knowledge, the first study of the effect of chronic pentolinium* treatment on the cardiac output and peripheral resistance in hypertensive patients. METHODSPatients studied were those with severe essential hypertension (blood pressures of 186-225/117-129). The cardiac output was performed in the seated position. The dye-dilution method of Stewart and Hamiltonl-5 as modified by Pritchard and his group' for the use of iodinated serum albumin (RISA) was the basic principle used in measuring cardiac output, except that arterial samples were collected in tubes rather than passed through the counting device

Studies of Pulmonary Hypertension. Ix. The Effects of Intravenous Hexamethonium on Pulmonary Circulation in Patients With Mitral Stenosis1

“…This pattern is different from that commonly observed in normal animals (20,21), in patients without cardiorespiratory disease (4), and in a variety of cardiorespiratory diseases other than mitral stenosis (1,6,8,22 Only five of our patients were found later to have abnormally high left ventricular diastolic pressures, and these were not those who had the most marked drops of pulmonary "capillary" pressure at catheterization.…”

Effects of Guanethidine, Reserpine, and Methyldopa on Reflex Venous and Arterial Constriction in Man*

“…It was recently demonstrated in anesthetized, openchest dogs that large doses of guanethidine and reserpine are capable of blocking the reflex venoconstriction that occurs during carotid arterial occlusion or central vagal stimulation (6). The possibility has been considered that blockade of reflex venoconstriction may also play a role in the clinical action of these and other antihypertensive drugs (5,(7)(8)(9)(10)(11)(12). Accordingly, this investigation was undertaken to determine the effects of guanethidine, reserpine, and methyldopa, when given to human subjects in the doses commonly employed clinically, on reflex regulation of forearm venous tone.…”

The Effects of Exercise on Central Blood Volume in Man

“…An augmentation of central blood volume has been demonstrated when an erect subject assumes the recumbent position (1-3), after the inflation of an antigravity suit (3,4), following immersion of the body in water (4), after the administration of sympathomimetic amines (5)(6)(7), and when large volumes of blood are transfused to subjects under ganglionic blockade (8). A shift of blood out of the thorax occurs when the erect position is assumed (1,2,9), following the application of spinal and general anesthesia (10), positive pressure breathing (7,11), the Flack maneuver (12), venous tourniquets to the extremities (3), and after the administration of ganglionic blocking agents (13,14). Considerable difference of opinion exists, however, regarding the influence of muscular exercise on the central blood volume.…”