Department of Internal Medicine and Cardiology, University Hospital Brno, Faculty of Medicine, Masaryk University, Jihlavská 20, 625 00, Brno, Czech Republic.
National Heart and Lung Institute, Imperial College, 72 Du Cane Rd, Shepherd's Bush, London, W12 0NN, England.
Sci Rep. 2020 Feb 13;10(1):2551. doi: 10.1038/s41598-020-59480-8.
On standard electrocardiogram (ECG) PQ interval is known to be moderately heart rate dependent, but no physiologic details of this dependency have been established. At the same time, PQ dynamics is a clear candidate for non-invasive assessment of atrial abnormalities including the risk of atrial fibrillation. We studied PQ heart rate dependency in 599 healthy subjects (aged 33.5 ± 9.3 years, 288 females) in whom drug-free day-time 12-lead ECG Holters were available. Of these, 752,517 ECG samples were selected (1256 ± 244 per subject) to measure PQ and QT intervals and P wave durations. For each measured ECG sample, 5-minute history of preceding cardiac cycles was also obtained. Although less rate dependent than the QT intervals (36 ± 19% of linear slopes), PQ intervals were found to be dependent on underlying cycle length in a highly curvilinear fashion with the dependency significantly more curved in females compared to males. The PQ interval also responded to the heart rate changes with a delay which was highly sex dependent (95% adaptation in females and males after 114.9 ± 81.1 vs 65.4 ± 64.3 seconds, respectively, p < 0.00001). P wave duration was even less rate dependent than the PQ interval (9 ± 10% of linear QT/RR slopes). Rate corrected P wave duration was marginally but significantly shorter in females than in males (106.8 ± 8.4 vs 110.2 ± 7.9 ms, p < 0.00001). In addition to establishing physiologic standards, the study suggests that the curvatures and adaptation delay of the PQ/cycle-length dependency should be included in future non-invasive studies of atrial depolarizations.
在标准心电图（ECG）中，PQ 间期已知与心率中度相关，但尚未确定这种依赖性的生理细节。同时，PQ 动力学是评估心房异常（包括心房颤动风险）的非侵入性候选指标。我们研究了 599 名健康受试者（年龄 33.5±9.3 岁，288 名女性）的 PQ 心率依赖性，这些受试者均有日间 12 导联 ECG 动态 Holter 记录。在这些受试者中，选择了 752,517 个 ECG 样本（每个受试者 1256±244 个）来测量 PQ 和 QT 间期以及 P 波持续时间。对于每个测量的 ECG 样本，还获取了之前 5 分钟的心脏周期历史记录。尽管 PQ 间期的心率依赖性不如 QT 间期（线性斜率的 36±19%），但 PQ 间期与潜在的心动周期长度呈高度曲线相关，女性的依赖性比男性更明显。PQ 间期也随着心率变化而延迟，这种延迟高度依赖于性别（女性和男性分别在 114.9±81.1 和 65.4±64.3 秒后适应 95%，p<0.00001）。P 波持续时间的心率依赖性甚至低于 PQ 间期（线性 QT/RR 斜率的 9±10%）。校正心率后的 P 波持续时间女性比男性略短但有显著差异（106.8±8.4 与 110.2±7.9 毫秒，p<0.00001）。除了建立生理标准外，该研究还表明，在未来的心房除极非侵入性研究中，应包括 PQ/心动周期长度依赖性的曲率和适应延迟。
