QT corrected for heart rate and qtc dispersion in Gujarati type 2 diabetics predominantly using preventive pharmacotherapy and with very low electrocardiogram left ventricular hypertrophy

Abstract

Background: There is a rising trend in the incidence of type 2 diabetes mellitus, and hyperglycaemia is known to cause cardiac dysautonomia, which may lead to life-threatening arrhythmias. It can be screened by simple electrocardiogram (ECG)-based QTc (QT corrected for heart rate) and QTd (QTc dispersion) indicating cardiac repolarisation abnormality. We studied QTc and QTd intervals in treated type 2 diabetics (T2D), testing the effect of age, gender, duration and control of disease. Materials and Methods: We conducted a cross-sectional study in a tertiary care teaching hospital of Gujarat, India, on 199 T2D (67 males and 132 females). Standard 12-lead ECG was recorded to derive QTc by Bazett's formula, QTd and ECG left ventricular hypertrophy (LVH). QTc >0.43 s in male and >0.45 s in female, QTd >80 msec were considered abnormal. Results: T2D (mean age 56 years, duration 6 years, coexisting hypertension 69%, glycaemic control 32% and use of β-blockers 56%) had QTc and QTd abnormality prevalence 15% and 20% respectively with ECG LVH prevailing in 3%. Male gender, poor glycaemic control and increased duration had negative impact on QT parameters with statistical significance only for first two and not for all results. Conclusion: Our study showed low-to-moderate prevalence of prolonged QTc and QTd, qualitatively more than quantitatively, in T2D with very low LVH and high prevalence of preventive pharmacotherapy, associated with male gender and glycaemic control. It underscores high risk of repolarisation abnormality, though moderate, that can be further primarily prevented by early screening and strict disease control.