Abstract 1327: The Duration of QRS Complex in Electrocardiogram is Related to the Risk of Sudden Cardiac Death
Objectives: Some previous studies indicate that increased duration of QRS complex in electrocardiogram (ECG) is related to the risk of all-cause death. However, the association of QRS duration ant the risk of sudden cardiac death (SCD) is not well documented in population studies. Our aim was to examine the relation of QRS duration with SCD in a population based sample of men.
Methods: This prospective study was based on 2038 men 42 to 60 years of age without left bundle branch block in ECG. The duration of QRS complex was measured on the basis of ECG at baseline.
Results: During the 17-year follow-up, there were 127 SCDs. As a continuous variable, QRS duration was related to the risk of SCD, after adjustment for age. Men with QRS duration of over 45 ms had 1.72-fold risk for SCD (95 % CI 1.22 to 2.49, p=0.002), after adjustment for other conventional risk factors (age, smoking, alcohol consumption, systolic blood pressure, body mass index, serum LDL and HDL cholesterol, prevalent coronary heart disease, type II diabetes, physical fitness). Among men with the highest quartile of QRS duration (over 45 ms) had a 1.83-fold (95 % CI 1.04 to 3.23, p=0.038) as compared to those with the lowest quartile of QRS duration, after adjustment for other risk factors. In addition to QRS, age, smoking, prevalent coronary heart disease, type II diabetes, and cardiorespiratory fitness were independently associated to the risk of SCD. Abnormally long QRS duration (over 120 ms) is an uncommon finding in normal population.
Conclusions: The duration of QRS complex in ECG is a predictor of SCD beyond that predicted by other conventional risk factors. The measurement of QRS duration should be taken into account while estimated the risk of SCD in general population.