Abstract Introduction: T-wave amplitude variability (TAV) is a noninvasive index of beat-to-beat variations in ventricular repolarization. Aim of the study was to evaluate whether this parameter might reflect the changes in ventricular repolarization process induced by myocardial reperfusion, in the setting of acute myocardial ischemia. Methods and results: 97 patients with diagnosis of non-ST-elevation myocardial infarction (NSTE-MI) eligible for coronary revascularization were studied. In each patient, a 20 minute three pseudo-orthogonal lead recording was obtained at admission and within few hours from angiography. TAV was computed with SyneTVar 3.10a software (ELA medical, SORIN Group, Paris, France). Twenty patients were excluded for technical reason. The remaining 77 patients, aged 68 ± 12.2 years, had a preserved left ventricular ejection fraction (54 ± 10.9 %). In comparison to the first measurement, there was a significant increase in mean TAV (from 20.4 ± 6.7µV to 23.2 ± 9.4µV, P = 0.02) only in patients who underwent coronary revascularization. The increase was more easily detectable in patients with revascularization of left anterior descending coronary artery (from 19.2 ± 7.4µV to 24.3 ± 10.2µV, P = 0.01). No differences were instead observed in patients who were not revascularized for either the lack of critical coronary stenosis or anatomical reasons. Conclusions: Percutaneous coronary revascularization in NSTE-MI patients is associated with a significant increase in TAV, which is likely to reflect the alterations of cardiac electrical properties induced by myocardial tissue reperfusion.
Keywords: myocardial ischemia; reperfusion arrhythmias; T-wave variability; ventricular repolarization; Holter recording