Effects of physical training on end-diastolic volume and myocardial performance of isolated rat hearts.
Open Access
- 1 May 1977
- journal article
- research article
- Published by Wolters Kluwer Health in Circulation Research
- Vol. 40 (5), 510-516
- https://doi.org/10.1161/01.res.40.5.510
Abstract
We studied the performance of ventricular muscle and cardiac function of hearts from rats conditioned by swimming (CH) and from sedentary rats (SH) in an isolated working heart apparatus modified to measure end-diastolic volume by dye dilution. Instantaneous aortic flow, left ventricular (LV) pressure and oxygen consumption were measured. Heart rate and mean aortic pressure were kept constant, and atrial filling pressure was varied from 5 to 20 cm H2O. Heart weights of SH and CH were equal and end-diastolic pressures and volumes were similar at all atrial pressures. However, ejection fraction, calculated circumferential fiber velocity, peak systolic pressure, peak aortic flow, cardiac output, and stroke work were all greater in CH than in SH, and the differences increased as atrial pressure was increased. Maximal negative dP/dt was greater in CH than SH at all preloads (P less than 0.001). Oxygen consumption of CH was increased in proportion to the increase in work. These results indicate that the improved pumping performance of CH is due to a change in ventricular muscle function. Faster relaxation is a prominent effect of physical training on the rat heart and may foster more complete filling at high heart rates.This publication has 12 references indexed in Scilit:
- Maximum exercise heart rate reduction with maturation in the ratJournal of Applied Physiology, 1976
- Dynamic stiffness profiles in the left ventricleJournal of Applied Physiology, 1975
- Density and Water Content of Dog Ventricular MyocardiumExperimental Biology and Medicine, 1972
- Effects of physical training on cardiac actomyosin adenosine triphosphatase activityAmerican Journal of Physiology-Legacy Content, 1972
- The effect of physical training upon the mechanical and metabolic performance of the rat heartJCI Insight, 1970
- Effect of pressure development on oxygen consumption by isolated rat heartAmerican Journal of Physiology-Legacy Content, 1967
- Measurement of left ventricular volume by thermodilution: an appraisal of technical errorsJournal of Applied Physiology, 1964
- Dynamic Response Characteristics of Systems for Continuous Recording of Concentration Changes in a Flowing Liquid (for Example, Indicator-Dilution Curves)Journal of Applied Physiology, 1957
- Effect of the Sampling System on the Shape of Indicator Dilution CurvesCirculation Research, 1957
- Estimation of the Residual Volume of the Ventricle of the Dog's Heart by Two Indicator Dilution TechnicsCirculation Research, 1956