Background: Microvolt T-wave alternans (MTWA) measures subtle beat-to-beat fluctuations in the T-wave amplitude. It was found to be associated with cardiac electrical instability in patients with ischemic and dilated cardiomyopathy.
Objectives: To investigate the reproducibility of the MTWA test results in patients with ischemic heart disease.
Methods: The study group comprised patients with ischemic heart disease who participated in a rehabilitation program at the Assaf Harofeh Medical Center. MTWA was measured during a bicycle exercise test at the first encounter and repeated after one week.
Results: Of the 40 study patients with coronary artery disease, 4 had an indeterminate result and were excluded from the data analysis; 5 had a positive MTWA in the first and second study (14%), 27 had a negative MTWA in the first and second study (75%), and 4 had a negative MTWA in the first study and a positive MTWA in the second study (11%). Overall, there was a correlation between the results of the first and the second study in 89% of the patients (kappa = 0.652, P = 0.0001).
Conclusions: MTWA measurements are reproducible in the short term in patients with coronary artery disease.