Lee J U, Kim K S, Kim J H, Lim H K, Lee B H, Lee C K
Department of Internal Medicine, College of Medicine, Hanyang University, Seoul, Korea.
Korean J Intern Med. 1995 Jul;10(2):137-42. doi: 10.3904/kjim.1995.10.2.137.
The PR interval on the electrocardiogram represents conduction time from the onset of atrial activation through His-Purkinje conduction system during a normal cardiac cycle. While its behavior at rest and during exposure to various cardioactive drugs is well documented, there exist few reports which describe PR interval variations during exercise in normal control and patient groups. In the present study, we examined the behavior of the PR intervals during various stages of exercise, and at the same time we observed whether the changes of PR interval during exercise could suggest that implanted cardiac pacemaker algorithms may be constructed to maximize hemodynamic benefits in patients requiring physiological cardiac pacemaker.
A retrospective analysis of the exercise treadmill test was performed on 148 healthy control group (148 males, mean age of 42.7 +/- 11.7) and 134 patient group (95 males & 39 females, mean age of 47.1 +/- 11.7) which had complained of non-specific chest symptoms but were identified as normal in the exercise treadmill test. During the test, we used the standard Bruce protocol. The results were expressed as mean +/- standard deviation, and differences in the mean value of each standard deviation, and differences in the mean value of each group were evaluated by the student's t-test. A P value of less than 0.05 was regarded as significant.
This study shows that PR interval changes corresponding to heart rate increments were linearly decreased. These changes of PR interval during exercise suggest that implanted cardiac pacemaker algorithms may be constructed to maximize hemodynamic benefits in patients requiring physiological cardiac pacemakers.
心电图上的PR间期代表在正常心动周期中从心房激动开始到希氏-浦肯野传导系统的传导时间。虽然其在静息状态及接触各种心脏活性药物时的表现已有充分记录，但很少有报告描述正常对照组和患者组在运动期间PR间期的变化。在本研究中，我们检查了运动各阶段PR间期的表现，同时观察运动期间PR间期的变化是否表明可以构建植入式心脏起搏器算法，以使需要生理性心脏起搏器的患者获得最大的血流动力学益处。
对148名健康对照组（148名男性，平均年龄42.7±11.7岁）和134名患者组（95名男性和39名女性，平均年龄47.1±11.7岁）进行运动平板试验的回顾性分析，这些患者曾抱怨有非特异性胸部症状，但在运动平板试验中被判定为正常。试验期间，我们采用标准布鲁斯方案。结果以平均值±标准差表示，通过学生t检验评估每个标准差平均值的差异以及每组平均值的差异。P值小于0.05被视为具有显著性。
1）对照组心率每增加10次/分钟，PR间期缩短率为6.9毫秒。2）整个患者组心率每增加10次/分钟，PR间期缩短率为5毫秒。3）男性患者组心率每增加10次/分钟，PR间期缩短率为5.2毫秒。4）女性患者组心率每增加10次/分钟，PR间期缩短率为4.3毫秒。5）在相同心率范围内，整个或男性患者组与对照组之间PR间期变化存在显著差异。
本研究表明，与心率增加相对应的PR间期变化呈线性下降。运动期间PR间期的这些变化表明，可以构建植入式心脏起搏器算法，以使需要生理性心脏起搏器的患者获得最大的血流动力学益处。
