{'fraction_non_alphanumeric': 0.03219034289713086, 'fraction_numerical': 0.02589223233030091, 'mean_word_length': 4.958333333333333, 'pattern_counts': {'":': 0, '<': 2, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Correlation of Signal‐Averaged P Wave with Electrophysiological Testing for Atrial Vulnerability in Strokes of Unexplained Etiology

Atrial fibrillation is considered the main cause of cardioembolic strokes. After detailed investigations, about 30% of ischemic strokes remain unexplained. A percentage of these ischemic attacks may result from asymptomatic episodes of paroxysmal atrial fibrillation (PAF). Previous studies have demonstrated that electrophysiological testing and signal‐averaged P wave (SAPW) ECG are useful to detect patients with PAF. Methods and Results: Twenty patients with unexplained ischemic strokes had electrophysiological studies (EPS) to determine atrial vulnerability and SAPW recordings. At EPS, patients were classified in group I (10 patients) if they had a latent atrial vulnerability index < 2 and/or more than 1 minute of sustained atrial arrhythmia. Otherwise they were classified in group II (10 patients). In group I, the filtered P wave duration was greater: 142 versus 120 msec (P = 0.03) and RMS 30 tended to he lower: 2.54 versus 4.13 μV (P = O.11) than in group II. A filtered P wave duration > 125 msec associated with a RMS 30 < 3 μV had a positive predictive value of 78% and a negative predictive value of 88% for the detection of patients with abnormal atrial vulnerability at EPS. Conclusions: SAPW may be useful to identify patients at risk of PAF who may be candidates for EPS.