3056Orthogonal P wave morphology, traditional P wave indices, and the risk of atrial fibrillation in the general population

• Published in: European heart journal 2019-10, Vol.40 (Supplement_1)
• Main Authors: Eranti, A, Carlson, J, Kentta, T V, Holmqvist, F, Holkeri, A, Haukilahti, M A, Kerola, T, Aro, A L, Rissanen, H, Noponen, K, Seppanen, T, Knekt, P, Huikuri, H V, Junttila, M J, Platonov, P G
• Format: Article
• Language: English
• ISSN: 0195-668X; 1522-9645
• DOI: 10.1093/eurheartj/ehz745.0023

Abstract Background A substantial portion of the risk of atrial fibrillation (AF) remains unexplained by the established risk markers. However, accurate assessment of AF risk would be beneficial, especially among stroke patients and subjects with symptoms attributable to arrhythmia. Purpose To study the associations of P-wave indices with AF risk in the general population. Methods Electrocardiograms, including orthogonal leads, of 7217 Finnish subjects aged over 30 years who took part in the baseline examinations of the Mini-Finland Health Survey in 1978–80, were digitized. P-wave duration, third-degree interatrial block (IAB), and P terminal force (PTF) were assessed manually. PTF was considered abnormal when the amplitude of the negative terminal part of the P wave in lead V1 was ≥0.1mV and duration ≥40ms. Third-degree IAB was defined as P-wave duration ≥120ms and the presence of ≥2 +/− biphasic P-waves in the inferior leads. Orthogonal P-wave morphology, which is related to left atrial breakthrough site and affected by atrial fibrosis (1 being considered benign, 2 borderline, and 3 shown to be associated with adverse events), was assessed with an automated algorithm, and ascertained manually. Subjects were followed 10 years for AF hospitalization and mortality. The risk of AF associated with P wave parameters was assessed using Cox proportional hazards models. Model discrimination improvement was quantified by the change in C index, integrated discrimination improvement (IDI), and continuous net reclassification improvement (cNRI). Results There were 5489 subjects (47.8% male, mean age 50.5 years) with a readable ECG, sinus rhythm, no missing data, and a predefined orthogonal P-wave morphology. Type 3 orthogonal P morphology (n=216, multivariate adjusted HR [maHR] 3.01, 95% confidence interval [CI] 1.66–5.45, p