Q waves and ventricular extrasystoles in resting electrocardiograms. A 16 year follow up in Busselton study

Area of Science:

• Cardiology
• Epidemiology
• Preventive Medicine

Background:

• Resting electrocardiograms (ECG) are crucial for cardiovascular risk assessment.
• Isolated ECG abnormalities in asymptomatic individuals require further investigation regarding prognostic value.
• Long-term mortality data can elucidate the clinical significance of subtle ECG findings.

Purpose of the Study:

• To investigate the relationship between isolated resting electrocardiogram (ECG) abnormalities and long-term mortality.
• To identify specific ECG findings predictive of coronary heart disease, cardiovascular disease, and all-cause mortality.
• To analyze these associations in a large, population-based cohort without prior cardiac history.

Main Methods:

• Analysis of resting ECGs from 1546 individuals in Busselton with no history of angina or myocardial infarction.
• 16-year follow-up for mortality data.
• Multivariate discriminant analysis to assess independent relationships between ECG abnormalities and mortality outcomes.

Main Results:

• In men, Q waves were independently associated with coronary heart disease mortality.
• In men, ventricular extrasystoles were independently associated with cardiovascular disease mortality.
• In women, ventricular extrasystoles were significantly related to total mortality and coronary heart disease mortality.
• Both men and women with frequent ventricular extrasystoles exhibited higher mortality trends compared to those with infrequent extrasystoles.

Conclusions:

• Isolated Q waves and ventricular extrasystoles on resting ECGs are significant predictors of mortality in individuals without known heart disease.
• Ventricular extrasystoles, particularly when frequent, indicate an elevated risk for cardiovascular and total mortality in both sexes.
• These findings highlight the prognostic importance of routine ECG screening for identifying at-risk populations.