Bacharova Ljuba, Kyselovic Jan, Klimas Jan
International Laser Center, Bratislava, Slovak Republic.
Clin Exp Hypertens. 2004 Aug;26(6):557-67. doi: 10.1081/ceh-200031835.
In this study we tested the hypothesis of the relative voltage deficit, i.e. the discrepancy between increased left ventricular mass (LVM) and QRS amplitudes, in an experimental model of spontaneously hypertensive rats (SHR) during the period of a moderate increase in blood pressure. To address this issue we recorded orthogonal electrocardiograms of male SHR at the age of 12 and 20 weeks. During this period the systolic blood pressure (sBP) increased from 165 +/- 3 mmHg to 195 +/- 1 mmHg (p < 0.001). Age and sex matched WKY rats were used as control groups. The sBP values in WKY normotensive control groups were within normal limits (122 +/- 8 mmHg and 130 +/- 4mmHg, respectively). The maximum QRS spatial vector magnitude (QRSmax) was calculated from X, Y, Z amplitudes of the orthogonal electrocardiograms. The animals were sacrificed and the left ventricular mass was weight. The specific potential of myocardium (SP) was calculated as a ratio of QRSmax to LVM. The LVM in SHR (0.86 +/- 0.05 g and 1.05 +/- 0.07 g, respectively) was significantly higher as compared to WKY (0.65 +/- 0.07 g and 0.70 +/- 0.02 g), and the increase of LVM closely correlated with the sBP increase. On the other hand, QRSmax in SHR did not follow either the increase of sBP, or LVM. The QRSmax values in SHR did not differ from those of WKY at the age of 12 weeks (0.59 +/- 0.14 mV compared to 0.46 +/- 0.05 mV), and they were even lower in SHR at the age of 20 weeks (0.74 +/- 0.08 mV compared to 0.44 +/- 0.05 mV, p < 0.001). The values of SP, quantifying the relative voltage deficit, were significantly lower in SHR as compared to the WKY control. The values decreased significantly in SHR with increasing age, sBP and LVM, i.e., with the progression of hypertrophic remodeling of the left ventricle. The results of this study support the hypothesis of the relative voltage deficit in LVH. These results are consistent with the finding of a high number of false negative ECG results in clinical ECG diagnostics of LVH, and could contribute to an understanding of the diagnostic importance of the false negative ECG results, their re-evaluation and utilization for clinical diagnosis and prognosis.
在本研究中，我们在血压适度升高期间的自发性高血压大鼠（SHR）实验模型中，检验了相对电压不足的假说，即左心室质量（LVM）增加与QRS波振幅之间的差异。为解决这一问题，我们记录了12周龄和20周龄雄性SHR的正交心电图。在此期间，收缩压（sBP）从165±3 mmHg升高至195±1 mmHg（p<0.001）。年龄和性别匹配的WKY大鼠用作对照组。WKY正常血压对照组的sBP值在正常范围内（分别为122±8 mmHg和130±4 mmHg）。从正交心电图的X、Y、Z振幅计算最大QRS空间向量幅度（QRSmax）。处死动物并称重左心室质量。心肌比电位（SP）计算为QRSmax与LVM的比值。与WKY相比，SHR的LVM（分别为0.86±0.05 g和1.05±0.07 g）显著更高（WKY为0.65±0.07 g和0.70±0.02 g），且LVM的增加与sBP的升高密切相关。另一方面，SHR中的QRSmax既不随sBP升高，也不随LVM增加。12周龄时SHR的QRSmax值与WKY无差异（分别为0.59±0.14 mV和0.46±0.05 mV），20周龄时SHR的QRSmax值甚至更低（分别为0.74±0.08 mV和0.44±0.05 mV，p<0.001）。量化相对电压不足的SP值在SHR中显著低于WKY对照组。随着年龄、sBP和LVM增加，即随着左心室肥厚重塑的进展，SHR中的SP值显著降低。本研究结果支持左心室肥厚中相对电压不足的假说。这些结果与左心室肥厚临床心电图诊断中大量假阴性心电图结果的发现一致，并可能有助于理解假阴性心电图结果的诊断重要性、重新评估以及在临床诊断和预后中的应用。
