External mechanical work during relaxation period does not affect myocardial oxygen consumption.
External mechanical work during relaxation period does not affect myocardial oxygen consumption.
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舒张期的外部机械功不影响心肌耗氧量。
DOI：
10.1152/ajpheart.1991.261.6.h1778
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
H. Suga
中科院分区：
文献类型：
--
作者：
K. Hata;Y. Goto;H. Suga
我们评价了松弛期外机械功(EW)对心肌耗氧量(VO2)的影响，阐明了犬左室压容面积(PVA)势能(PE)部分的能量意义。在测量VO2的同时，在不改变P-V轨迹的舒张末容积(EDV)和收缩段的情况下，通过在给定的PVA内增加或减小EW来改变P-V轨迹的松弛段的轨迹。因此，在RP过程中，脑室经历了射血或充盈。虽然EW占PVA的百分比(%EW/PVA)从32+/-12(SD)显著增加到射出收缩(8例)的93+/-3%和等容收缩(3例)的0到93+/-5%，但%EW/PVA的这些显著变化对VO2无显著影响。此外，这些过程中的VO2-PVA数据落在通过改变等容收缩的EDV和PVA而获得的参考VO2-PVA关系线上。我们的结论是，在PVA一定的情况下，快速反转过程中的EW不会影响VO2，部分PE可以以能量等效的方式转化为EW。
We assessed the effect of external mechanical work (EW) during the relaxation period (RP) on myocardial oxygen consumption (VO2) and clarified the energetic significance of the potential energy (PE) portion of the pressure-volume area (PVA) in the cross-circulated dog left ventricle. We changed the course of the relaxation segment of the pressure-volume (P-V) trajectory by increasing or decreasing EW within a given PVA without changing the end-diastolic volume (EDV) and the systolic segment of the P-V trajectory while measuring VO2. Thus the ventricle underwent ejection or filling during RP. Although the percent fraction of EW in PVA (%EW/PVA) was markedly increased from 32 +/- 12 (SD) to 93 +/- 3% in ejecting contractions (8 hearts) and from 0 to 93 +/- 5% in isovolumic contractions (3 hearts), these marked changes in %EW/PVA did not significantly affect VO2. Moreover, the VO2-PVA data during these procedures fell on the reference VO2-PVA relation line obtained by changing EDV and PVA of isovolumic contractions. We conclude that EW during RP at a constant PVA does not affect VO2 and part of PE can be converted into EW in an energetically equivalent manner.