Loewe Axel, Krueger Martin W, Holmqvist Fredrik, Dössel Olaf, Seemann Gunnar, Platonov Pyotr G
Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76128, Karlsruhe, Germany
Institute of Biomedical Engineering, Karlsruhe Institute of Technology (KIT), Kaiserstr. 12, 76128, Karlsruhe, Germany.
Europace. 2016 Dec;18(suppl 4):iv35-iv43. doi: 10.1093/europace/euw349.
P-wave morphology correlates with the risk for atrial fibrillation (AF). Left atrial (LA) enlargement could explain both the higher risk for AF and higher P-wave terminal force (PTF) in lead V. However, PTF-V has been shown to correlate poorly with LA size. We hypothesize that PTF-V is also affected by the earliest activated site (EAS) in the right atrium and its proximity to inter-atrial connections (IAC), which both show tremendous variability.
Atrial excitation was triggered from seven different EAS in a cohort of eight anatomically personalized computational models. The posterior IACs were non-conductive in a second set of simulations. Body surface ECGs were computed and separated by left and right atrial contributions. Mid-septal EAS yielded the highest PTF-V. More anterior/superior and more inferior EAS yielded lower absolute PTF-V values deviating by a factor of up to 2.0 for adjacent EAS. Earliest right-to-left activation was conducted via Bachmann's Bundle (BB) for anterior/superior EAS and shifted towards posterior IACs for more inferior EAS. Non-conducting posterior IACs increased PTF-V by up to 150% compared to intact posterior IACs for inferior EAS. LA contribution to the P-wave integral was 24% on average.
The electrical contributor's site of earliest activation and intactness of posterior IACs affect PTF-V significantly by changing LA breakthrough sites independent from LA size. This should be considered for interpretation of electrocardiographical signs of LA abnormality and LA enlargement.
P波形态与心房颤动（AF）风险相关。左心房（LA）扩大可解释AF风险增加以及V导联中较高的P波终末电势（PTF）。然而，PTF-V已被证明与LA大小相关性较差。我们推测PTF-V也受右心房最早激动部位（EAS）及其与房间连接（IAC）的接近程度影响，这两者均表现出极大变异性。
在一组8个解剖学个性化计算模型中，从7个不同的EAS触发心房激动。在第二组模拟中，后IAC不导电。计算体表心电图并按左、右心房贡献分开。中隔EAS产生最高的PTF-V。更靠前/靠上和更靠下的EAS产生较低的绝对PTF-V值，相邻EAS的偏差高达2.0倍。对于靠前/靠上的EAS，最早的右向左激动通过Bachmann束（BB）传导，对于更靠下的EAS则向后IAC转移。与完整后IAC相比，对于靠下的EAS，不导电的后IAC使PTF-V增加高达150%。LA对P波积分的贡献平均为24%。
最早激动的电激动部位和后IAC的完整性通过改变LA突破部位而显著影响PTF-V，与LA大小无关。在解释LA异常和LA扩大的心电图征象时应考虑这一点。
