THE EFFECT OF THE VALSALVA MANEUVER ON THE CINCULATION. II. - The role of the autonomic nervous system in the production of the overshoot
Journal/Book: Reprinted from AMERICAN HEART JOURNAL St. Louis Vol. 45 No. 2 Pages 227-236 February 1953 (Printed in the U.S.A.). 1953;
Abstract: SUMMARY 1. Mitral valvular disease prevents the overshoot in blood pressure and bradycardia normally seen after a Valsalva maneuver. It does so by preventing sufficient blood from reaching the periphery in the post-straining period despite normal reflexes. 2. Tetraethylammonium chloride also prevents this overshoot and bradycardia by blocking vasopressor reflexes during and immediately alter sustained straining. 3. Atropine blocks the parasympathetic nervous system and the overshoot in pressure in Phase 4 is exaggerated and prolonged while the bradycardia is abolished. Increased cardiac output after atropine acting in the presence of a constricted arterial system may partially explain the exaggerated overshoot in Phase 4. 4. Venous pressure rises in a similar manner during straining even after the administration of tetraethylammonium chloride or atropine. We are indebted to the volunteers who were the subjects of this study and to Dr. Gerald Graham for drawing our attention to the studies of Matthes. . . .