PP.16.12

Abstract

Objective: The transitional zone (clockwise/ counterclockwise rotation) in an electrocardiogram (ECG) during sinus rhythm is a simple, distinct, and common finding. No prospective study has examined the association between transitional zones and incident cardiovascular diseases (CVDs) in general population. We assessed the hypothesis that, compared to normal rotation, counterclockwise and clockwise rotation is associated with poor and good risk of CVDs, respectively. Design and method: We evaluated the 5,331 study participants (30–83 years; 47% men) without prior CVDs in a prospective cohort of the Japanese urban population. In a resting 12- lead ECG, the transitional zone was classified as counterclockwise, normal, or clockwise rotation. Cox regression analyses were performed to estimate the hazard ratios (HRs) of CVDs after adjusting for other cardiovascular risk factors. Results: During 13.1 years of follow-up, 410 CVDs and 175 coronary heart diseases were observed. Among men, the prevalence of hypertension in the counterclockwise, normal, or clockwise rotation group was 28, 34, and 40%, respectively (p < 0.01). Among women, the prevalence of hypertension in the counterclockwise, normal, or clockwise rotation group was 23, 29, and 35%, respectively (p < 0.01). Compared with normal rotation, counterclockwise rotation was significantly associated with decreased risk of CVDs incidences in women (HR (95% confidence interval [CI]): 0.64 (0.42–0.97)). In the stratified analyses, counterclockwise rotation was significantly related with decreased risks of CVDs incidences in women with lower cardiovascular risks, the relatively younger participants, never cigarette smokers, never alcohol drinkers and those without hypertension, hypercholesterolemia or abdominal obesity. Meanwhile, in the stratified analyses of men, clockwise rotation was significantly related with elevated risks of CVDs incidences in the never-smokers, but related with decreased risk of CVDs in the ever-smokers (HRs (95% CI): 2.64 (1.16–6.02) and 0.65 (0.43–0.98), respectively, Interaction p = 0.01). Conclusions: Counterclockwise rotation in 12-lead ECG was associated with decreased risks of CVDs in the urban Japanese women. Clockwise rotation was significantly related with elevated risks of CVDs incidences in the never-smoking men. This is the first prospective cohort study that the transitional zones in ECG could be useful to estimate elevated or decreased risks of CVDs incidences.