Analysis of cardiac sarcomere efficiency and heat generation

The efficiency of the heart is studied at the sarcomere level in order to find an optimal operating point for the heart. At this point, the heart is said to be best coupled or 'matched' to the circulation. The effects of pacing versus no pacing and of acute versus chronic adaptation are considered. These effects are studied in a mathematical model. The rate of heat loss in the sarcomere is assumed to balance the rate of production. This phenomenon is studied under both constant heart rate and/or constant mean aortic pressure. The results show a maximum in the rate of heat loss when the heart rate is constant. However, for a given mean aortic pressure, the rate of heat loss determines the cardiac output. This latter case is shown to be dependent on the left ventricular size.<
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