Hemodynamic responses to induced tachycardia in methylene blue-treated dogs

¹ Cardiopulmonary Research Laboratory, Department of Medicine, University of Wisconsin Medical School, Madison, Wisconsin

The present study relates to metabolic, and systemic and coronary hemodynamic effects of methylene blue in five anesthetized dogs (group I) and of electrically induced tachycardia in ten dogs pretreated with methylene blue (group II). In group I body oxygen consumption increased slightly. In group II coronary blood flow, cardiac metabolic rate for oxygen, and right ventricular work increased significantly while coronary vascular resistance decreased significantly. The observed pattern of changes is not different from that produced by induced tachycardia in untreated dogs. Methylene blue does not alter the usual response of coronary circulation to cardiac acceleration.

Key Words: hemodynamic effects of methylene blue • methylene blue and control of coronary blood flow • control of peripheral circulation • metabolism and tissue flow • oxidation and reduction potential and blood flow

Submitted on July 31, 1963