QT dispersion increases with aging.

BACKGROUND: Age-related changes in cardiovascular system are well-known. Arrhythmias in elderly patients constitute most of the urgencies, consultations, or hospitalizations. QT dispersion (QTd) is a simple noninvasive arrhythmogenic marker to demonstrate the electrical instability of the heart. The aim of this study was to investigate how QTd changes with increasing age by calculating the QTd in the elderly and younger subjects.

METHODS: One hundred and forty-six consecutive subjects (62 males and 84 females; age range: 18-82 years) were enrolled in the study. Sixty-seven of the subjects were 65 years and over (mean age, 70 +/- 4), 79 were younger than 65 (mean age, 37 +/- 11). A 12-lead ECG was recorded. The longest and the shortest QT intervals were measured manually on these ECG recordings. QTd was calculated from the formula, QTd = QTmax - QTmin.

RESULTS: Demographic features were similar between the two groups. QTd of the elderly group was found to be significantly higher than the younger group (35.6 +/- 15.6 in elderly, 24.2 +/- 12.4 in younger group, P < 0.001). A positive relationship was found between QTd and age (r = 0.415, P < 0.001). QTd was greater in female than in male (31.9 +/- 16.7 ms vs 26.0 +/- 11.3 ms, respectively, P = 0.018).

CONCLUSIONS: Our study shows that QTd increases with advancing age. We think that long-term follow-up of these patients would be useful to show if there is any relationship between the clinical outcomes and the increase in QTd.