Flat T wave

A decreased-amplitude ventricular repolarization wave on the ECG, in which the T wave appears low due to abnormal ventricular repolarization. Possible causes are myocardial ischemia, electrolyte disturbance (hypokalemia, hypomagnesemia, hypocalcemia), medications (diuretics, tricyclic antidepressants, digoxin), myocardial hypertrophy, myocarditis, hypothyroidism, and pericardial effusion.