增加前,后负荷对右心室心肌收缩性指标的影响

EFFECT OF INCREASING PRELOAD AND AFTERLOAD ON THE MYOCARDIAL CONTRACTILITY INDICES OF RIGHT VENTRICLE

Preload, afterload and contractility of right ventricle were increased experimentally in 7 dogs by means of rapid infusion of dextran, increase of alveolar pressure after toracotomy and injection of isoprenaline. The changes of the indices of myocardial contractility of the right ventricle were compared and observed. The dp/dt max and Vpm were very sensitive to the inotropic factor, but were greatly influenced by the change of the myocardial load. The rest indices of the right ventricle were not sensitive or scattered widely dp/dt max and Vpm of the right ventricle were more susceptible to the interference of respiration than those of the left ventricle. None of these indices can be properly used as a single index to indicate the right ventricle contractility. Observing dp/dt max and Vpm of the right ventricle we can qualitatively understand the changing trend of the contractility and load of the right ventricle.