Faerestrand S, Ohm O J
Pacing Clin Electrophysiol. 1985 Nov;8(6):838-48. doi: 10.1111/j.1540-8159.1985.tb05903.x.
We have used Doppler echocardiography to estimate the stroke volume (SV) in a study of 13 patients equipped with DDD pacemakers. SV was measured both during DDD and VVI pacing after observation times of 1,3,6, and 12 months of DDD pacing. SV was also measured at seven atrioventricular (AV) intervals (75-250 ms) in the search for optimal AV intervals. Mitral flow velocity was investigated to see if DDD pacing resulted in synchronous atrial contraction, and if mitral insufficiency existed at any of the pacing modes. Compared with the VVI mode, DDD pacing resulted in a mean increase in SV of 21 +/- 2% for the four observation periods. Two patients with severe left ventricular failure had no significant increase in SV during DDD vs VVI pacing. In each patient, an optimal AV interval ranging between 100-250 ms for the SV was found. Velocity profiles of mitral flow showed synchronous atrial contraction during DDD pacing, but not during VVI pacing. Mitral insufficiency was not seen in any pacing mode. DDD pacing resulted in a reduction in SV during the first 6 months, and was constant thereafter. Doppler echocardiography can be used repeatedly to evaluate the hemodynamic response of DDD pacing vs VVI pacing, and to find which AV interval gives the highest SV in the individual patient. Our study further shows that the hemodynamic benefit of DDD pacing is present after short-term as well as after long-term DDD pacing.
我们在一项针对13例植入DDD起搏器患者的研究中，使用多普勒超声心动图来估算每搏输出量（SV）。在DDD起搏1、3、6和12个月的观察期后，分别测量了DDD起搏和VVI起搏期间的SV。还在7个房室（AV）间期（75 - 250毫秒）测量了SV，以寻找最佳AV间期。研究二尖瓣血流速度，以观察DDD起搏是否导致心房同步收缩，以及在任何起搏模式下是否存在二尖瓣关闭不全。与VVI模式相比，在四个观察期内，DDD起搏使SV平均增加了21±2%。两名严重左心室衰竭患者在DDD起搏与VVI起搏期间SV无显著增加。在每位患者中，发现使SV最佳的AV间期在100 - 250毫秒之间。二尖瓣血流速度曲线显示，DDD起搏期间心房同步收缩，而VVI起搏期间则不然。在任何起搏模式下均未发现二尖瓣关闭不全。DDD起搏在最初6个月使SV降低，此后保持稳定。多普勒超声心动图可反复用于评估DDD起搏与VVI起搏的血流动力学反应，并找出个体患者中使SV最高的AV间期。我们的研究进一步表明，短期和长期DDD起搏后均存在DDD起搏的血流动力学益处。
