Prevalence and prognosis of ECG abnormalities in normotensive and hypertensive individuals.

OBJECTIVE: To define the prevalence and prognosis of ECG abnormalities in hypertensive individuals.

METHODS: ECG, blood pressure and other cardiovascular risk factors were recorded in a nationwide population sample of 5800 Finns. The presence of 15 ECG abnormalities was evaluated. Participants were divided into categories by blood pressure and followed for coronary heart (CHD) and cardiovascular disease (CVD) events.

RESULTS: Mean follow-up was 10.4 ± 2.2 years. The age- and sex-adjusted prevalence rates of ECG abnormalities were generally higher in the hypertensive participants than in normotensive individuals. In multivariable-adjusted Cox models, the following ECG abnormalities predicted CHD in hypertensive participants: left ventricular hypertrophy (LVH) by Sokolow-Lyon criteria [hazard ratio, 1.47; 95% confidence interval (CI), 1.07-2.01; P = 0.02], LVH with ST-depression and negative T wave (ST/T changes) (hazard ratio, 2.31; 95% CI, 1.20-4.43, P = 0.01), ST/T changes (hazard ratio, 2.12; 95% CI, 1.34-3.36; P = 0.001), positive T wave in lead aVR (AVRT+) (hazard ratio, 1.74; 95% CI, 1.15-2.64; P = 0.009) and poor R-wave progression (hazard ratio, 2.02; 95% CI, 1.27-3.22; P = 0.003). These ECG abnormalities were also significant predictors of CVD in hypertensive participants (P ≤ 0.03 for all). Nonspecific intraventricular conduction delay predicted CVD in the whole population (hazard ratio, 1.50; 95% CI, 1.06-2.13; P = 0.02). Prolonged QT interval, abnormal P-wave indices, left axis deviation and early repolarization pattern were not associated with CHD or CVD.

CONCLUSION: ECG abnormalities are highly prevalent in hypertensive individuals. LVH is still the cornerstone of cardiovascular risk assessment in hypertensive patients. The additional assessment of ST/T changes, AVRT+ and poor R-wave progression in ECGs could improve risk prediction in hypertensive patients.