Yamamoto K, Burnett J C, Meyer L M, Sinclair L, Stevens T L, Redfield M M
Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
Am J Physiol. 1996 Dec;271(6 Pt 2):R1529-34. doi: 10.1152/ajpregu.1996.271.6.R1529.
This study was designed to characterize left ventricular (LV) function and mass in a modified cardiomyopathy model in the dog in which right ventricular pacing rates are gradually increased throughout 38 days. On the last day of the pacing protocol, ejection fraction was reduced (25 +/- 3 vs. 60 +/- 1%) and LV end-diastolic diameter index (a ratio of LV end-diastolic diameter to body weight, 2.09 +/- 0.02 vs. 1.79 +/- 0.08 mm/kg) and LV mass index (a ratio of LV mass to body weight, 5.2 +/- 0.3 vs. 4.3 +/- 0.2 g/kg) were greater than in the normal dogs (P < 0.05, respectively). Cardiac filling pressures increased, and LV diastolic function and coronary blood flow were impaired. After 4 wk of recovery from the progressive pacing protocol, LV end-diastolic diameter index (2.12 +/- 0.06 mm/kg) and LV mass index (5.6 +/- 0.2 g/kg) remained increased. Ejection fraction was improved (38 +/- 4%) but still depressed. LV diastolic function, coronary blood flow, and cardiac filling pressures returned to levels seen in the normal dogs. This modified cardiomyopathy model associated with LV hypertrophy complements the conventional tachycardia-induced cardiomyopathy model without LV hypertrophy.
本研究旨在对犬类改良型心肌病模型的左心室（LV）功能和质量进行表征，该模型在38天内逐渐增加右心室起搏频率。在起搏方案的最后一天，射血分数降低（25±3%对60±1%），左心室舒张末期直径指数（左心室舒张末期直径与体重之比，2.09±0.02对1.79±0.08mm/kg）和左心室质量指数（左心室质量与体重之比，5.2±0.3对4.3±0.2g/kg）均高于正常犬（P均<0.05）。心脏充盈压升高，左心室舒张功能和冠状动脉血流受损。在从渐进性起搏方案恢复4周后，左心室舒张末期直径指数（2.12±0.06mm/kg）和左心室质量指数（5.6±0.2g/kg）仍升高。射血分数有所改善（38±4%）但仍较低。左心室舒张功能、冠状动脉血流和心脏充盈压恢复到正常犬的水平。这种与左心室肥厚相关的改良型心肌病模型补充了无左心室肥厚的传统心动过速诱导型心肌病模型。
