ALTERATIONS IN LEFT-VENTRICULAR DIASTOLIC FUNCTION IN CONSCIOUS DOGS WITH PACING-INDUCED HEART-FAILURE
ALTERATIONS IN LEFT-VENTRICULAR DIASTOLIC FUNCTION IN CONSCIOUS DOGS WITH PACING-INDUCED HEART-FAILURE
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DOI：
10.1172/jci115787
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发表时间：
1992-06-01
影响因子：
15.9
通讯作者：
VATNER, SF
中科院分区：
文献类型：
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作者：
KOMAMURA, K;SHANNON, RP;VATNER, SF
我们在清醒的狗中研究了（a）慢性快速心室起搏诱导的心力衰竭对左心室（LV）舒张功能障碍与收缩功能障碍发展顺序的影响，以及（B）这些变化是否是负荷依赖性的或继发于结构的改变。LV收缩和舒张功能障碍在起搏开始后24小时内明显，并在3周内平行发生。LV收缩功能在3周时降低，即，LV dP/dt峰值下降-1，327 +/-105 mmHg/s，射血分数下降-22+/-2%。LV舒张功能障碍也在起搏3周内进展，即，tau增加了+14.0+/-2.8 ms，心肌硬度常数增加了+6.5+/-1.4，而LV腔硬度没有变化。这些变化与LV收缩末期（+28.6+/-5.7 g/cm 2）和LV舒张末期应力（+40.4+/-5.3 g/cm 2）增加相关。当压力和心率在控制和失败状态下匹配在相同的水平时，不再观察到tau蛋白和心肌硬度的增加，而LV收缩功能仍然受到抑制。心力衰竭时结缔组织含量无增加。因此，清醒犬起搏诱导的心力衰竭的特征在于舒张功能的重大改变，这是可逆的，增加负荷条件的正常化。
We investigated in conscious dogs (a) the effects of heart failure induced by chronic rapid ventricular pacing on the sequence of development of left ventricular (LV) diastolic versus systolic dysfunction and (b) whether the changes were load dependent or secondary to alterations in structure. LV systolic and diastolic dysfunction were evident within 24 h after initiation of pacing and occurred in parallel over 3 wk. LV systolic function was reduced at 3 wk, i.e., peak LV dP/dt fell by -1,327+/-105 mmHg/s and ejection fraction by -22+/-2%. LV diastolic dysfunction also progressed over 3 wk of pacing, i.e., tau increased by +14.0+/-2.8 ms and the myocardial stiffness constant by +6.5+/-1.4, whereas LV chamber stiffness did not change. These alterations were associated with increases in LV end-systolic (+28.6+/-5.7 g/cm2) and LV end-diastolic stresses (+40.4+/-5.3 g/cm2). When stresses and heart rate were matched at the same levels in the control and failure states, the increases in tau and myocardial stiffness were no longer observed, whereas LV systolic function remained depressed. There were no increases in connective tissue content in heart failure. Thus, pacing-induced heart failure in conscious dogs is characterized by major alterations in diastolic function which are reversible with normalization of increased loading condition.