Introduction: The P-wave analysis of the ECG signal provides detailed insights into the atrial electrical impulse path, detecting potential anomalies indicative of atrial arrhythmias. Recent scientific evidence prompts a new paradigm for the relationship between atrial fibrillation (AF) and stroke according to which post-stroke pathophysiology is complex and can lead to atrial cardiomyopathy causing AF. Therefore, identifying predictive factors within the P-wave becomes crucial for better risk stratification of post-stroke AF, ultimately optimizing patient treatment and management. Traditionally, given the low SNR associated with the P-wave, the analysis of the P-wave features has been performed on the averaged P-wave template technique. Alternatively, approaches focusing on maximizing P-wave amplitude in ECG leads were explored. Technological advancement enables high-resolution ECG (with LSB < 0.1uV) allowing beat-by-beat P-wave analysis, even for single-lead ECG. This paper aimed to analyze the potential of single-lead ECG P-wave analysis in indicating atrial substrate modification correlated with post-stroke pathophysiology.
Methods:66 patients with ischemic stroke were recruited and initiated EKG continuous monitoring immediately after stroke onset for 7 days. On day 2, a 5-minute-long EKG trace was recorded for each patient using a single-lead high-resolution acquisition system. The extracted P-waves were analyzed for duration (Pdur), fragmentation (Pfrag), change of polarity (PCP), and beat-to-beat variability (Pvar). The study population was divided into AF-detected and control groups, with statistical significance assessed using the Mann-Whitney unpaired t-test.
Results: AF was detected in 15 patients. All P-wave parameters resulted to be higher in patients with AF in the control group (Pdur: 104,5+/-23,3 ms vs. 133,3+/-6,4 ms, p<0,01, Pfrag: 2,28+/-1,4 vs 3,8+/-1,7, p<0,05, PCP 0,68+/-0,6 vs 1,3+/-0,5, p<0,05, Pvar 0,22+/-0,09 vs 0,29 +/- 0,09, p<0,05).
Conclusions: This study showed for the first time the potential link between single-lead ECG P-wave analysis and the electrophysiological changes of the atria in post-stroke patients.