The incidence of notch on QRS wave in electrocardiogram and associated risk factors in the elderly

Objective To investigate the incidence of notch on QRS wave in electrocardiogram (ECG) and its associated risk factors in the elderly. Methods A total of 2 328 elderly subjects undergoing physical examination from January to December 2012 were grouped according to age, medical history and physical examination findings. The ECG leads of notch on QRS wave were classified, and its related risk factors were analyzed. Results The incidence of notch on QRS wave in ECG was 28.1% (655/2 328) in the elderly. There was a significant difference in the incidence of notch on QRS wave in ECG between people with and without the history of past diseases 〔32.2% (444/1 378) vs. 22.2% (211/950), P<0.01〕. The incidences of notch on QRS wave in ECG in aged 66-70, 71-75, 76-80 and over 80 years groups were 23.8% (241/1 012), 28.9% (257/890), 33.6% (109/324) and 47.1% (48/102), respectively. The incidence of notch on QRS wave in lateral, lateral-anterior, anterior leads were 68.1% (446/655), 14.5% (95/655) and 10.2% (67/655) . Coexistence of various diseases, hypertension, coronary heart disease and age were the risk factors for notch on QRS wave in ECG. Conclusions A higher incidence of notch on QRS wave in ECG are found in elderly people, and most of them occur in inferior leads. Both the age and the heart-related diseases are the important risk factors for the notch on QRS wave in ECG. Key words: Electrocardiography; Diabetes mellitus; Hypertension; Coronary disease