Dzikowicz DJ, et al. - In this secondary data analysis, researchers evaluated the links between obesity, hypertension, and the interplay between them on QRS duration (QRSd). Participants were firefighters (n=77) without documented cardiovascular disease in normal sinus rhythm, with most (89.4%) being overweight or obese. Mean QRSd was measured by twelve-lead 24-hr electrocardiogram Holter monitors. They measured as well as classified body mass index (BMI) and resting blood pressure (BP). They used BMI, BP, and the interaction between BMI and BP as factors related to QRSd, to generate univariate linear regression models. Findings revealed independent associations of increased BMI and of interaction between BMI and systolic BP, with prolongation of the QRS complex.