Left ventricle heat production in intact anesthetized dogs

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

Only a part of heat produced by the left ventricle is removed by the coronary blood. During a cold saline infusion into the right ventricle, LV myocardial temperature decreases and the myocardium loses a measurable amount of heat. A part of this heat is also removed by the coronary blood. If simultaneous thermal curves are recorded from the aorta and coronary sinus during the infusion it is possible to calculate left ventricle heat production by the following formula: H = LV weight x T x t x K x 60:A, where T = myocardial temperature drop during the infusion; t = coronary sinus-aorta blood temperature difference prior to infusion; K = specific heat of myocardium; A = difference of areas of superimposed coronary sinus and aorta's thermal curves. Heat production estimated by the formula in 19 determinations has been compared with the heat production calculated from myocardial oxygen consumption. Measurements obtained by this method seem to be representative of left ventricle heat production.

Key Words: LV heat production • myocardial heat • cardiac energetics

Submitted on June 8, 1964