Introduction Partial and advanced interatrial block (IAB) in the ECG represents inter-atrial conduction delay. IAB is associated with atrial fibrillation (AF) and stroke in the general population. Material and methodsA representative sample of Finnish subjects (n=6 354) aged over 30 years (mean 52.2 years, SD 14.6) underwent a health examination including a 12-lead ECG. Five different IAB groups based on automatic measurements were compared to normal P waves using multivariate-adjusted Cox proportional hazard model. Follow-up lasted up to 15 years. ResultsThe prevalence of advanced and partial IAB was 1.0% and 9.7%, respectively. In the multivariate model, both advanced (hazard ratio [HR] 1.63 [95% CI 1.00 -2.65]) and partial IAB (HR 1.39 [1.09 -1.77]) were associated with increased risk of AF. Advanced IAB was associated with increased risk of stroke or transient ischemic attack (TIA) independently of associated AF ). Partial IAB was also associated with increased risk of being diagnosed with coronary heart disease ).Discussion IAB is a rather frequent finding in the general population. IAB is a risk factor for AF and is associated with an increased risk of stroke or TIA independently of associated AF. Key messages1. Both partial and advanced interatrial block are associated with increased risk of atrial fibrillation in the general population.2. Advanced interatrial block is an independent risk factor for stroke and transient ischemic attack.3. The clinical significance of interatrial block is dependent on the subtype classification.

Background Inverted T waves in the electrocardiogram (ECG) have been associated with coronary heart disease (CHD) and mortality. The pathophysiology and prognostic significance of T‐wave inversion may differ between different anatomical lead groups, but scientific data related to this issue is scarce. Methods A representative sample of Finnish subjects (n = 6,354) aged over 30 years underwent a health examination including a 12‐lead ECG in the Health 2000 survey. ECGs with T‐wave inversions were divided into three anatomical lead groups (anterior, lateral, and inferior) and were compared to ECGs with no pathological T‐wave inversions in multivariable‐adjusted Fine–Gray and Cox regression hazard models using CHD and mortality as endpoints. Results The follow‐up for both CHD and mortality lasted approximately fifteen years (median value with interquartile ranges between 14.9 and 15.3). In multivariate‐adjusted models, anterior and lateral (but not inferior) T‐wave inversions associated with increased risk of CHD (HR: 2.37 [95% confidence interval 1.20–4.68] and 1.65 [1.27–2.15], respectively). In multivariable analyses, only lateral T‐wave inversions associated with increased risk of mortality in the entire study population (HR 1.51 [1.26–1.81]) as well as among individuals with no CHD at baseline (HR 1.59 [1.29–1.96]). Conclusions The prognostic information of inverted T waves differs between anatomical lead groups. T‐wave inversion in the anterior and lateral lead groups is independently associated with the risk of CHD, and lateral T‐wave inversion is also associated with increased risk of mortality. Inverted T wave in the inferior lead group proved to be a benign phenomenon.

No abstract