Transient regional ischemia during PTCA induced T-wave alternans in 33.7% of patients, with the highest prevalence (51.7%) during left anterior descending artery occlusion.
Observational (n=95)
Does transient regional ischemia during PTCA induce T-wave alternans in patients?
Transient regional ischemia during PTCA induces T-wave alternans in about one-third of patients, particularly those with LAD occlusion, highlighting the regional nature of ischemia-induced repolarization changes.
T-wave alternans (TWA) has been linked to increased vulnerability to ventricular fibrillation in different settings including myocardial ischemia. In this study, we propose a methodology for the characterization of TWA induced by transient, regional ischemia. We studied the prevalence, magnitude and spatio-temporal relationship between TWA and ischemia in 95 patients undergoing percutaneous transluminal coronary angioplasty (PTCA). Two electrocardiogram records of each patient, a control recording before PTCA and the PTCA record, were analyzed using a robust, recently proposed method for TWA analysis. The detected episodes were characterized in terms of their time-course, lead distribution and alternans waveform. One third of the patients (33.7%) showed TWA episodes during PTCA. The highest prevalence (51.7%) and amplitude were found in patients with left anterior descendent artery occlusion. The onset of TWA was detected after the first 1-2 min of occlusion, suggesting that some level of ischemia must be attained before TWA arises, while disappearance of TWA following reperfusion was much more rapid. The TWA lead distributions and waveforms showed distinct distributions according to the occluded artery reflecting the regional nature of the TWA phenomenon.
Martínez et al. (2006) conducted an observational in Myocardial ischemia (n=95). Transient regional ischemia during PTCA vs. Control recording before PTCA was evaluated on Prevalence of T-wave alternans (TWA) episodes. Transient regional ischemia during PTCA induced T-wave alternans in 33.7% of patients, with the highest prevalence (51.7%) during left anterior descending artery occlusion.