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首页> 外文期刊>American Journal of Physiology >Assessment of left ventricular diastolic suction in dogs using wave-intensity analysis.
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Assessment of left ventricular diastolic suction in dogs using wave-intensity analysis.

机译：使用波强度分析评估狗的左心室舒张压。

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Two apparently different types of mechanisms have emerged to explain diastolic suction (DS), that property of the left ventricle (LV) that tends to cause it to refill itself during early diastole independent of any force from the left atrium (LA). By means of the first mechanism, DS depends on decreased elastance [e.g., the relaxation time constant (tau)] and, by the second, end-systolic volume (V(LVES)). We used wave-intensity analysis (WIA) to measure the total energy transported by the backward expansion wave (I(W-)) during LV relaxation in an attempt to reconcile these mechanisms. In six anesthetized, open-chest dogs, we measured aortic, LV (P(LV)), LA (P(LA)), and pericardial pressures and LV volume by orthogonal ultrasonic crystals. Mitral velocity was measured by Doppler echocardiography, and aortic velocity was measured by an ultrasonic flow probe. Heart rate was controlled by pacing, V(LVES) by volume loading, and tau by isoproterenol or esmolol administration. I(W-) was found to be inversely related to tau and V(LVES). Our measure of DS, the energy remaining after mitral valve opening, I(W-DS), was also found to be inversely related to tau and V(LVES) and was approximately 10% of the total "aspirating" energy generated by LV relaxation (i.e., I(W-)). The size of the Doppler (early filling) E wave depended on I(W-DS) in addition to I(W+), the energy associated with LA decompression. We conclude that the energy of the backward-going wave generated by the LV during relaxation depends on both the rate at which elastance decreases (i.e., tau) and V(LVES). WIA provides a new approach for assessing DS and reconciles those two previously proposed mechanisms. The E wave depends on DS in addition to LA decompression.
机译：已经出现了两种明显不同类型的机制来解释舒张期吸引（DS），即左心室（LV）的这种特性倾向于使舒张期在早期舒张期重新充盈，而与来自左心房（LA）的力无关。通过第一种机制，DS取决于降低的弹性[例如，松弛时间常数（tau）]，并且取决于第二种收缩末期容积（V（LVES））。我们使用波强度分析（WIA）来测量左心室舒张期间由后向膨胀波（I（W-））传输的总能量，以使这些机制协调一致。在六只麻醉的，开胸的狗中，我们通过正交超声晶体测量了主动脉，LV（P（LV）），LA（P（LA））以及心包压力和LV体积。二尖瓣速度通过多普勒超声心动图测量，主动脉速度通过超声流量探针测量。心率通过起搏控制，V（LVES）通过体积负荷控制，tau通过异丙肾上腺素或艾司洛尔给药来控制。发现I（W-）与tau和V（LVES）成反比。我们的DS测量值，即二尖瓣打开后剩余的能量I（W-DS），也与tau和V（LVES）成反比，大约是LV松弛产生的总“抽吸”能量的10％ （即I（W-））。多普勒（早期充盈）E波的大小除了I（W +）以外，还取决于I（W-DS），I（W +）是与LA减压相关的能量。我们得出的结论是，在松弛过程中，由LV产生的后向波的能量取决于弹性降低的速率（即tau）和V（LVES）。 WIA提供了一种评估DS的新方法，并协调了之前提出的这两种机制。除LA减压外，E波还取决于DS。

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