MICROVOLT T WAVE ALTERNANS IS ASSOCIATED WITH LEFT VENTRICLE REMODELING AFTER MYOCARDIAL INFARCTION AHA 2002
Kaoru Tanno
Authors: Youichi Kobayashi; Mitsuharu Kawamura; Yoshino Minoura; Norikazu Watanabe; Kaoru Tanno; Akira Miyata
8:00 - 1:00

Clinical reports suggest that microvolt T-wave alternans (TWA) is useful to predict VT in patients with ischemic heart disease. Left ventricle (LV) after myocardial infarction (MI) leads to enlargement and partial hypertrophy, that is called ventricular remodeling. The aim of this study is to elucidate the relation between TWA and ventricular remodeling after MI. [Method] In 165 patients (62+/-10 years, M/F=147/18) who underwent emergent percutaneous coronary intervention because of acute myocardial infarction, TWA measurement using bicycle exercise and cardiac catheterization were performed 6 months after onset of MI. TWA was considered positive when the alternans voltage (Valt) was >1.9μV and the alternans ratio was >3 for more than 1 minute in VM, X, Y, Z, or two adjacent precordial leads (sustained alternans). [Results] TWA was positive (P) in 39 patients (24%), negative (N) in 102 patients (62%), and indeterminate in 24 patients (14%). LV end-systolic volume of P group was significantly higher than that of N group (59+/-24 vs. 42+/-17 ml, p<0.01), and LVEF of P group was significantly lower than that of N group (44+/-13 vs. 55+/-11%, p<0.01). In addition, brain natriuretic peptide was significantly higher in P group than N group (157+/-234 vs. 66+/-66 pg/ml, p<0.01). Although there is no significant difference of LV function at onset of MI between P and N groups, LVEF of P group was significantly decreased 6 months after MI (47.9+/-10.1 44.8+/-13.1 %, p<0.05), while LVEF of N group was significantly increased (50.6+/-12.1 54.6+/-11.3 %, p<0.05). [Conclusions] These results suggest that positive TWA might be closely associated with LV remodeling after MI.