Guth B D, Schulz R, Heusch G
Abteilung für Pathophysiologie, Universität Essen, FRG.
Basic Res Cardiol. 1990 Nov-Dec;85(6):550-62. doi: 10.1007/BF01907890.
The primary purpose of this study was to evaluate parameters used for the measurement of regional myocardial contractile function in the setting of left ventricular (LV) asynchrony. Secondarily, we tested whether the peak negative value of left ventricular dP/dt (-dP/dt) can be used to estimate global LV end-systole during asynchrony. In seven anesthetized (Isoflurane) swine the left anterior descending coronary artery was cannulated and perfused at constant blood flow rates. To produce LV asynchrony, dobutamine (D) was infused into the perfusion system. This was repeated later during coronary hypoperfusion (HYPO) sufficient to produce regional contractile dysfunction. The amount of LV wall thickening during systole (% WT, sonomicrometry) was calculated using either -dP/dt or the closure of the aortic valve (AO, electromagnetic flow probe) for estimating the timing of global LV end-systole. % WT was compared to other parameters which are not dependent upon the timing of global LV end-systole, including the amplitude of the first harmonic of the Fourier transform (AMP) and regional myocardial work (WI) estimated form the left ventricular pressure-wall thickness relationship. A close correlation between global LV end-systole defined by the AO or -dP/dt existed during control, D or HYPO. During HYPO + D no such relationship was found (r = .22, NS), and % WT calculated using -dP/dt as an estimate of end-systole was underestimated when compared to % WT calculated by use of the AO to estimate end-systole (2.9 +/- 6.8% vs 6.3 +/- 6.6%, p less than .05). % WT, AMP, and WI showed similar results during control, D and HYPO. However, During HYPO increased the AMP from .59 +/- .23 mm to .76 +/- .32 mm and WI from 67 +/- 20 mm Hgmm to 95 +/- 24 mm Hgmm (p less than .05), respectively. This increase in regional myocardial function, however, was not detected by % WT (10.5 +/- 6.4% vs 6.3 +/- 6.6%). Thus, during left ventricular asynchrony, the measurement of LV -dP/dt to estimate the timing of global LV end-systole is inappropriate and can lead to inaccuracies in the measurement of regional contractile function. Parameters such as AMP or WI are advantageous since global LV end-systole does not need to be accurately defined.
本研究的主要目的是评估在左心室（LV）不同步情况下用于测量局部心肌收缩功能的参数。其次，我们测试了左心室dP/dt的峰值负值（-dP/dt）是否可用于估计不同步期间的左心室整体收缩末期。在七只麻醉（异氟烷）猪中，对左前降支冠状动脉进行插管并以恒定血流速率灌注。为产生左心室不同步，将多巴酚丁胺（D）注入灌注系统。在足以导致局部收缩功能障碍的冠状动脉低灌注（HYPO）期间稍后重复此操作。使用-dP/dt或主动脉瓣关闭（AO，电磁流量探头）来估计左心室整体收缩末期的时间，计算收缩期左心室壁增厚量（%WT，超声心动图）。将%WT与其他不依赖于左心室整体收缩末期时间的参数进行比较，包括傅里叶变换的一次谐波幅度（AMP）和根据左心室压力-壁厚度关系估计的局部心肌功（WI）。在对照、D或HYPO期间，由AO或-dP/dt定义的左心室整体收缩末期之间存在密切相关性。在HYPO + D期间未发现这种关系（r = 0.22，无显著性差异），与使用AO估计收缩末期计算的%WT相比，使用-dP/dt作为收缩末期估计值计算的%WT被低估（2.9±6.8%对6.3±6.6%，p < 0.05）。在对照、D和HYPO期间，%WT、AMP和WI显示出相似的结果。然而，在HYPO期间，AMP分别从0.59±0.23 mm增加到0.76±0.32 mm，WI从67±20 mmHgmm增加到95±24 mmHgmm（p < 0.05）。然而，这种局部心肌功能的增加未被%WT检测到（10.5±6.4%对6.3±6.6%）。因此，在左心室不同步期间，使用左心室-dP/dt来估计左心室整体收缩末期的时间是不合适的，并且可能导致局部收缩功能测量不准确。诸如AMP或WI等参数具有优势，因为不需要准确界定左心室整体收缩末期。
