An Experimental Study on the Right Ventricular Systonic Time Interval : It's Time Relationship to Rvmax dp/dt in Experimentally Induced Pulmonary Hypertention

This study was undertaken to investigate behaviors of right heart regarding ventricular systonic time interval (RVSTI) in acute pulmonary hypertension. Acute pulmonary hypertension　was produced experimentally in 7 healthy mongrel dogs by injecting carbon grains suspemded in normal saline through a catheter placed in right ventricle. Increasing amounts of carbon grains were injected discontinuously　montitoring pulmonary artery mean pressure (Pam). Intraventricular pressure curve, right ventricular maximum rate of pressure elevation (Rvmaxdp/dt) and ECG were recorded when Pam reached to arbitrarily selected 3 to 7 levels. RVSTI consisting of preejection period (PEP), ejection time (ET) and PEP/ET were measured. In addition, Rvmaxdp/dt, time interval berween Q wave on ECG to Rvmaxdp/dt (Q-Rvmaxdp/dt), and (Q-Rvmaxdp/dt) -RVPEP were also determined. The results were as followings