Detecting the Elusive P-Wave: A New ECG Lead to Improve the Recording of Atrial Activity

Goal: In this study, we report on a lead selection method that was developed to detect the optimal bipolar electrode placement for recording of the P-wave. Methods: The study population consisted of 117 lead body surface potential maps recorded from 229 healthy subjects. The optimal bipolar lead was developed using the training set (172 subjects) then extracted from the testing dataset (57 subjects) and compared to other lead systems previously reported for improved recording of atrial activity. All leads were assessed in terms of P-wave, QRS, and STT root mean square (RMS). The P/QRST RMS ratio was also investigated to determine the atrioventricular RMS ratio. Finally, the effect of minor electrode misplacements on the P-lead was investigated. Results: The P-lead discovered in this study outperformed all other investigated leads in terms of P-wave RMS. The P-lead showed a significant improvement in median P-wave RMS (93 versus 72 μV, p <; 0.001) over the next best lead, Lead II. An improvement in QRS and STT RMS was also observed from the P-lead in comparison to lead II (668 versus 573 μV, p <; 0.001) and (327 versus 196 μV, p <; 0.001). Although P-wave RMS was reduced by incorrect electrode placement, significant improvement over Lead II was still evident. Conclusion: The P-lead improves P-wave RMS signal strength over all other investigated leads. Also the P-lead does not reduce QRS and STT RMS making it an appropriate choice for atrial arrhythmia monitoring. Significance: Given the improvement in signal-to-noise ratio, an improvement in algorithms that rely on P-wave analysis may be achieved.