U wave on ECG

U wave on ECG

U wave is a wave in the ECG (electrocardiogram) which occurs after the T wave and is usually seen in the mid precordial (chest) leads. In hypokalemia (low levels of potassium in blood), T wave becomes flattened and U wave becomes prominent. U wave can become in inverted when blood supply to the heart muscle is reduced, in certain cases (myocardial ischemia).