Dependence of canine right coronary arterial flow upon heart rate and right ventricular pressure

为了阐明右冠状动脉（RCA）应对过载的确切机制，我们研究了9只开胸成年比格犬，并分析了RCA血流信号与独立变化的心率（起搏）和右心室压力（肺动脉束带）的关系。心率和右心室压力的增加都增加了RCA的总容积流量。舒张总流量比（D/T）随右心室压升高而增大，随心率升高而下降。我们的数据也证实，心率上升时RCA流量增加主要是由收缩期增加引起的，而右心室压力增加主要是由舒张期增加引起的。RCA设法以两种不同的方式将血液输送到右心室肌肉组织，以应对心率和心室压力的增加。长期实验的最终结论尚未得出。我们落后于计划，部分原因是我周围的情况发生了一些不可避免的变化。我们计划在1996年按照原方案再做一些实验来完成研究。

To elucidate the exact mechanisms for the right coronary artery (RCA) to cope with the overload, we studied nine open-chest adult Beagles and analyzed the flow signals of the RCA in relation to independently varied heart rate (pacing) and right ventricular pressure (pulmonary artery banding).Both increased heart rate and right ventricular pressure increased the total volume flow of the RCA.The diastolic over total flow ratio (D/T), however, enlarged on increasing right ventricular pressure while it declined on increasing heart rates. Our data confirmed, as well, that increased flow of RCA on rising heart rate was provided mainly by an increase in systolic phase, while the increase on augmented right ventricular pressure was provided by the increase in diastolic phase. The RCA manages to deliver blood to the right ventricular musculature in two different ways in response to increasing heart rate and ventricular pressure.Final conclusion from chronic experiments is not reached yet. We are left behind the schedule, partly because of some unavoidable alterations of situations around me. We are planning to do some more experiments according to the original protocol in 1996 to complete the study.