Interatrial block and P terminal force in the general population - Longitudinal changes, risk factors and prognosis.

BACKGROUND: Partial and advanced interatrial block (IAB) and P terminal force (PTF) in lead V1 are markers of atrial remodeling and risk factors for atrial fibrillation (AF). There is a lack of information about constancy and possible factors influencing the development of these P-wave abnormalities. METHODS: The study sample consisted of 6058 Finnish participants (mean age 52.16 ± 14.60 years, 45.0% male) from the general population with an ECG taken in a health examination, and from 3224 of these participants, who had a re-examination 11 years later. Risk factors for incident partial and advanced IAB and PTF were studied using binomial logistic regression analysis, and the prognostic significance of these ECG changes for new AF was studied using time-varying Cox regression analysis. RESULTS: The rate of reversal to normal of the studied ECG parameters were 47.4% for partial IAB, 40.0% for advanced IAB and 79.3% for PTF. Age, male sex, hypertension, higher BMI, higher LDL cholesterol, ECG left ventricular hypertrophy, use of beta blocker, and use of angiotensin-converting enzyme inhibitor or angiotensin II receptor antagonist were independently associated with a risk to develop incident P-wave abnormality. Partial IAB was independently associated with increased AF risk (HR 1.28 [95% CI 1.04-1.58]), as was also advanced IAB (HR 1.72 [95% CI 1.07-2.75]). CONCLUSION: Traditional cardiovascular risk factors increase the risk of a new P-wave abnormality. Partial and advanced IAB are associated with increased AF risk. Surprisingly, P-wave abnormalities are often reversible during long-term follow-up in the general population.

The prognostic significance of T-wave inversion according to ECG lead group during long-term follow-up in the general population.

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.

The prevalence and prognostic significance of interatrial block in the general population.

Introduction: Partial and advanced interatrial block (IAB) in the electrocardiographic (ECG) represents inter-atrial conduction delay. IAB is associated with atrial fibrillation (AF) and stroke in the general population.Material and methods: A representative sample of Finnish subjects (n = 6354) aged over 30 years (mean: 52.2 years, standard deviation: 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.Results: The 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% confidence interval (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 ischaemic attack (TIA) independently of associated AF (HR: 2.22 (1.20-4.13)). Partial IAB was also associated with increased risk of being diagnosed with coronary heart disease (HR: 1.26 (1.01-1.58)).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 messagesBoth partial and advanced interatrial block are associated with increased risk of atrial fibrillation in the general population.Advanced interatrial block is an independent risk factor for stroke and transient ischaemic attack.The clinical significance of interatrial block is dependent on the subtype classification.

Long-term prognostic significance of the ST level and ST slope in the 12­lead ECG in the general population.

BACKGROUND: Even minor ST depression in the electrocardiogram (ECG) is associated with cardiovascular disease and increased mortality. There is limited data on the prognostic significance of ST-level changes in the general population. SUBJECTS AND METHODS: A random sample of Finnish subjects (n = 6354) aged over 30 years (56.1% women) underwent a health examination including a 12­lead ECG in the Health 2000 survey. The effects of relative ST level as a continuous variable and ST slope (upsloping, horizontal, downsloping) in three different lead groups were analyzed using a multi-adjusted Cox proportional hazard model separately for men and women with total mortality as endpoint. RESULTS: The follow-up lasted for 13.7 (SD 3.3) years for men and 13.9 (SD 3.1) years for women. Lower lateral ST levels were associated with all-cause mortality in multi-adjusted models in both genders (at J + 80 ms hazard ratio [HR] 0.64 for a change of 1.0 mm [95% confidence interval 0.49-0.84, p = 0.002] for men and HR 0.61 [0.48-0.78, p < 0.001] for women). Associated coronary heart disease had no major influence on the results. Exclusion of subjects with ECG signs of left ventricular hypertrophy from the analyses increased the mortality risk of lower lateral ST levels in men but decreased it in women. For the anterior and inferior lead groups, no statistically significant difference was seen after multivariate adjustment. ST slope was not an independent predictor of mortality after multivariate adjustment. CONCLUSION: Lower ST level in the lateral ECG leads is an independent prognostic factor to predict all-cause mortality in the general population.