QTc intervals in healthy weight stable obese subjects

ABSTRACT

115 healthy obese subjects [25 males and 90 females] were selected from outpatient clinics. QT intervals corrected for heart rate using Bazett and Framingham equations were measured. There was a nonsignificant correlation observed between absolute QT-interval duration and body mass index [BMI]. But significant correlations were found between Bazett-QTc [B-QTc] and Framingham-QTc [F-QTc] and BMI. The main change in obesity was a progressive shortening of the RR interval with increasing fatness, that is resting heart rate increased with increasing BMI. 18.5% of subjects had B-QTc >0.44 second, however, only 8% had F-QTc >0.44 second. These findings suggested that obesity may be one of the most common causes of prolonged QTc interval, although the actual cause is still unknown, but progressive shortening of RR duration with increasing BMI that may be due to decreased cardiac vagal activity in obese subjects could explain this prolongation of QTc but evaluation of the clinical significance of this observation may be a crucial task for further research