Prevalence of T Wave Alternans in Diabetic Subjects

Purpose:

Microvolt T Wave Alternans (MTWA) is an important noninvasive prognostic tool for prediction of arrhythmic events in patients with structural heart diseases. In subjects without heart diseases presence of MTWA is reported about 1-2%. No data are available about MTWA in patients with type II diabete, a population at high risk of cardiovascular disease. Aim of this study is to verify the prevalence of MTWA in patients with type II diabete.

Methods:

MTWA was assessed during bicycle stress test using HearTwave System - Cambridge Heart - in 45 diabetics volunteers without previous diagnosis of heart disease, with normal ECG, <10 premature ventricular beats/hr and normal exercise test. Mean age was 66±5 years (49-75); males were 35 (77%).

Results:

In no patient was observed MTWA at rest; only 2 (4.4%) subjects presented indeterminate test. Sustained MTWA at an onset heart rate <110 bpm, considered positive MTWA, was observed in 9 (20%) patients.

Conclusions:

Prevalence of positive MTWA in diabetics type II is high and seems confirm the high cardiovascular risk of this population. Probably a larger group of patients with a long follow up could help to better understand the prognostic value of this test respect to ventricular arrhythmias and total mortality.