Kolettis T M, Kremastinos D T, Kyriakides Z S, Tsirakos A, Toutouzas P K
Department of Cardiology, Athens General Hospital, Greece.
Pacing Clin Electrophysiol. 1995 Sep;18(9 Pt 1):1628-35. doi: 10.1111/j.1540-8159.1995.tb06984.x.
Experimental animal data have indicated that altered left ventricular depolarization sequence as a result of right ventricular pacing may diminish coronary blood flow in the distribution of the left anterior descending coronary artery. To further investigate this, we compared the effects of atrial, ventricular, and atrioventricular (AV) sequential pacing on coronary flow reserve. Twenty-seven patients (24 male, mean age 55 +/- 7 years) with normal left anterior descending coronary arteries were studied. Coronary flow reserve was calculated as the ratio of mean flow velocity at maximal coronary vasodilatation to mean flow velocity at baseline. The study consisted of two parts. In the first part, AV sequential pacing was compared to atrial pacing at the same rate; coronary flow reserve did not differ significantly between the two pacing modes (14 patients, 4.85 +/- 1.88 vs 5.47 +/- 1.55, respectively, P > 0.05). In the second part, all three pacing modalities were compared; coronary flow reserve was significantly higher during ventricular compared to AV sequential pacing, but not significantly different compared to atrial pacing (3.69 +/- 1.42 vs 2.90 +/- 0.86 vs 3.11 +/- 0.89, respectively, P < 0.05). This difference was secondary to a significant decrease in mean baseline velocity during ventricular pacing, while mean velocity during hyperemia was comparable between the three pacing modes. It is concluded that AV sequential pacing does not appear to exert a significant effect on coronary flow reserve. Ventricular pacing, however, may lower resting coronary blood velocity in some patients, without affecting maximal coronary blood velocity, resulting in a higher coronary flow reserve.
实验动物数据表明，右心室起搏导致的左心室去极化顺序改变可能会减少左前降支冠状动脉分布区域的冠状动脉血流。为进一步研究这一问题，我们比较了心房起搏、心室起搏和房室（AV）顺序起搏对冠状动脉血流储备的影响。对27例左前降支冠状动脉正常的患者（24例男性，平均年龄55±7岁）进行了研究。冠状动脉血流储备通过最大冠状动脉血管扩张时的平均流速与基线时的平均流速之比来计算。该研究包括两个部分。在第一部分中，将AV顺序起搏与相同频率的心房起搏进行比较；两种起搏模式下的冠状动脉血流储备无显著差异（14例患者，分别为4.85±1.88和5.47±1.55，P>0.05）。在第二部分中，对所有三种起搏方式进行了比较；与AV顺序起搏相比，心室起搏时的冠状动脉血流储备显著更高，但与心房起搏相比无显著差异（分别为3.69±1.42、2.90±0.86和3.11±0.89，P<0.05）。这种差异是由于心室起搏期间平均基线速度显著降低，而三种起搏模式下充血期间的平均速度相当。结论是，AV顺序起搏似乎对冠状动脉血流储备没有显著影响。然而，心室起搏可能会降低一些患者静息时的冠状动脉血流速度，而不影响最大冠状动脉血流速度，从而导致更高的冠状动脉血流储备。
