左室负荷改变及缺血对犬左室舒张早期血流的影响

目的　探讨舒张早期二尖瓣血流E波速度在负荷改变及缺血状态下的变化规律。方法　在犬应用脉冲波多普勒测量左室对照状态、负荷改变及缺血状态下二尖瓣瓣尖及瓣下1cm及2cm三个取样点的E波流速，各点心电图R波顶峰至E波顶峰的时间(R-E)变化，同时用心导管法测量左室松弛时间常数(T)，分析各指标的变化规律并了解与T值变化之间的关系。结果　二尖瓣血流速度在左室内的衰减为非线性，与静息状态相比速度衰减幅度由25%增加到39%，二尖瓣血流时间指标R-E受负荷影响小，受缺血的影响显著与静息状态相比缺血状态下，R-E

The influence of load changes and ischemia on canine left ventricular diastolic blood flow

OBJECTIVE: To find the relation between left ventricular diastolic function and left ventricular diastolic blood flow. METHODS: At control, load change and ischemic states, left ventriculer relaxation time constant (T) was measured by catheter and echocardiographic indexes were measured at dogs. Echocardiographic indexes included mitral peak flow velocity E at mitral tip level (E(0)) and at 1 cm and 2 cm below the mitral tip toward the apex (E(1) and E(2)) and the interval from ECG peak of R to the peak of velocity E (R-E(0), R-E(1), R-E(2)). RESULTS: The left ventricular diastolic blood flow decreased nonlinearly at every states, and interval indexes were independent of the changes of loads but both kinds of indexes were affected markedly by myocardial ischemia. CONCLUSION: Ischemia decreases left ventricular diastolic function and increases left ventricular diastolic blood flow attenuation.