Cardiac arrhythmias and atrioventricular block in a cohort of asymptomatic individuals without heart disease

Aims: To evaluate cardiac arrhythmias and rhythm disturbances on 24 h ambulatory electrocardiographic monitoring in a cohort of asymptomatic healthy individuals with normal clinical examination. Methods and Results: 625 asymptomatic healthy individuals, in the age range 15-83 (mean 42, SD 11.9) years; 276 (44.2%) men and 349 (55.8%) women were submitted to 24-hour ambulatory electrocardiographic monitoring. Statistical analysis was performed with likelihood ratio test and automatic backward logistic regression. The frequency of atrial arrhythmias (p < 0.0001; OR 1.059; 95% CI 1.050-1068) and of ventricular arrhythmias (p < 0.0001; OR 1.023; 95% CI 1.017-1.029) increased for each age increase of 1 year; neither atrial nor ventricular arrhythmias demonstrated a statistically significant difference relative to gender. Transient second-degree atrioventricular block ( Mobitz I) was observed in 14 (2.2%) individuals and was more frequent in individuals with resting heart rate < 60 bpm (p = 0.006; OR 6.7, 95% CI 1.7-25.5). Conclusion: The frequency of atrial and ventricular arrhythmias increasedwith age and did not demonstrate a significant difference relative to gender. Transient atrioventricular block was more frequent in individuals with lower resting heart rate. Copyright (c) 2007 S. Karger AG, Basel.