Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia.
Cardiology Division, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, Virginia.
J Cardiovasc Electrophysiol. 2019 Oct;30(10):1952-1959. doi: 10.1111/jce.14067. Epub 2019 Aug 1.
Frequent premature ventricular contractions (PVCs) can cause cardiomyopathy (CM). Postextrasystolic potentiation (PESP) and irregularity have been in implicated as triggers of PVC-CM. Because both phenomena can also be found in premature atrial contractions (PACs), it is speculated that frequent PACs have similar consequences.
A single-center, retrospective study included all consecutive patients undergoing a 14-day Holter monitors (November 2014 to October 2016). Patients were divided into four groups by ectopy burden group 1 (<1%) and remaining by tertiles (group 2-4). Echocardiographic and arrhythmic data were compared between PAC and PVC burdens. In addition, a translational PAC animal model was used to assess the chronic effects of frequent PACs. A total 846 patients were reviewed. In contrast to PVCs, we found no difference in left ventricular ejection fraction (LVEF), end-systolic and end-diastolic dimensions and presence of CM (LVEF <50%) between different PAC groups. Multivariate regression analysis demonstrated that only PVC burden predicted low EF (odds ratio, 1.1; confidence interval, 1.03-1.13; P = .001). While there was a weak correlation between PAC burden and supraventricular tachycardia (SVT) episodes and atrial fibrillation (AF) burden (r = 0.19; P < .001), there was no correlation between PAC burden and LVEF or CM. Finally, atrial bigeminy in our animal model did not significantly decrease LVEF after 3 months.
PAC burden is associated with increased AF and SVT episodes. In contrast to a high PVC burden, a high PAC burden is not associated with CM. Our findings suggest that heart rate irregularity and/or PESP may play a minimal role in the pathophysiology of PVC-CM.
频发的室性早搏（PVC）可导致心肌病（CM）。继发收缩后增强（PESP）和不规则性被认为是 PVC-CM 的触发因素。由于这两种现象也可在房性早搏（PAC）中发现，因此推测频发的 PAC 具有相似的后果。
一项单中心回顾性研究纳入了所有连续接受 14 天动态心电图监测的患者（2014 年 11 月至 2016 年 10 月）。患者根据异位搏动负担分为 1 组（<1%）和其余组（2-4 组）。比较 PAC 和 PVC 负荷之间的超声心动图和心律失常数据。此外，还使用翻译 PAC 动物模型评估频繁 PAC 的慢性影响。共回顾 846 例患者。与 PVC 不同，我们在不同 PAC 组之间未发现左心室射血分数（LVEF）、收缩末期和舒张末期直径以及 CM（LVEF<50%）存在差异。多变量回归分析表明，只有 PVC 负荷预测 EF 降低（比值比，1.1；置信区间，1.03-1.13；P=0.001）。虽然 PAC 负荷与室上性心动过速（SVT）发作和心房颤动（AF）负荷之间存在弱相关性（r=0.19；P<0.001），但 PAC 负荷与 LVEF 或 CM 之间无相关性。最后，我们的动物模型中房性二联律在 3 个月后并未显著降低 LVEF。
PAC 负荷与 AF 和 SVT 发作增加相关。与高 PVC 负荷相比，高 PAC 负荷与 CM 无关。我们的研究结果表明，心率不规则和/或 PESP 在 PVC-CM 的病理生理学中可能发挥最小作用。
