Soliman Elsayed Z, Rautaharju Pentti M
Division of Public Health Sciences, Department of Epidemiology and Prevention, Epidemiological Cardiology Research Center (EPICARE),Wake Forest University School of Medicine, Winston Salem, NC, USA.
J Electrocardiol. 2012 Jan-Feb;45(1):66-9. doi: 10.1016/j.jelectrocard.2011.06.003. Epub 2011 Jul 23.
Prolonged PR interval has been associated with adverse cardiac events. Consequently, the scientific community and regulatory agencies have become concerned about PR interval prolongation induced by cardioactive agents. We evaluated PR dependence on heart rate (HR) in 5757 men and women aged 40 years and older from the US third National Health and Nutrition Survey with the objective to determine if rate adjustment for the PR interval is warranted as is the case with QT interval. Electrocardiograms were computer-processed in a central electrocardiogram laboratory. There was a statistically significant negative correlation between PR and HR (r = -0.15; P < .001); notably weaker than that between QT and HR (r = -0.76; P < .001). Evaluation of subgroups stratified by sex, race, and age revealed a significant interaction between PR and HR with age (P = .006). A subsequent search for optimal rate-adjusted PR (PRa) formula that eliminates PR dependence on HR within each age group produced the formula: PRa = PR + 0.26 (HR - 70) for age group younger than 60 years and PRa = PR + 0.42 (HR - 70) for age group 60 years or older. The application of this formula in the study population effectively made the PR interval rate-invariant (residual slope of regression, -0.0054; 95% confidence interval, -0.064 to 0.053; P = .86). Based on the distribution of PRa, the 98th percentile limit of 220 milliseconds would be a reasonable overall threshold for defining first-degree AV block, with the 95th percentile limit of 205 as a threshold for borderline PR prolongation. In conclusion, the association between PR and HR is age- and rate-dependent and a separate rate-adjustment formula is needed for adults in younger and older age groups. The prognostic significance of the rate-adjusted PR needs to be investigated.
PR间期延长与不良心脏事件相关。因此，科学界和监管机构已开始关注心脏活性药物引起的PR间期延长。我们在美国第三次国家健康与营养调查中，对5757名年龄在40岁及以上的男性和女性进行了PR间期对心率（HR）依赖性的评估，目的是确定是否像QT间期那样有必要对PR间期进行心率校正。心电图在中央心电图实验室进行计算机处理。PR间期与心率之间存在显著的负相关（r = -0.15；P < 0.001）；明显弱于QT间期与心率之间的相关性（r = -0.76；P < 0.001）。按性别、种族和年龄分层的亚组评估显示，PR间期与心率之间存在显著的年龄交互作用（P = 0.006）。随后对最佳心率校正PR（PRa）公式进行搜索，该公式可消除各年龄组内PR间期对心率的依赖性，得出公式：年龄小于60岁的组，PRa = PR + 0.26（HR - 70）；年龄60岁及以上的组，PRa = PR + 0.42（HR - 70）。该公式在研究人群中的应用有效地使PR间期心率不变（回归残差斜率，-0.0054；95%置信区间，-0.064至0.053；P = 0.86）。根据PRa的分布，220毫秒的第98百分位数限值将是定义一度房室传导阻滞的合理总体阈值，205毫秒的第95百分位数限值作为PR间期临界延长的阈值。总之，PR间期与心率之间的关联具有年龄和心率依赖性，年轻和老年成人需要单独的心率校正公式。心率校正PR间期的预后意义有待研究。
