normal wave:
positive with amplitude of +0.2mV..
abnormalities:
may be absent,negative or biphasic.
cause:
normal wave is due to repolarisation of apex & outer surface of ventricleahead of the intraventricular surfaces.. so an abnormal T-wave indicates that there is a defect in normal mode of repolarisation..
diseased states associated with abnormal T-wave:
mild ischemia is the most common cause..Ischemia causes shortening of depolarisation of cardiac muscle and this causes a incresed current flow through potassium channels to be recorded as an abnormal T-wave..ischemia results from chronic,progressive coronary occlusion; acute coronary occlusion;or relative coronary insufficiency that occurs during exercise.digitalis toxicity can also cause an abnormal T-wave.
other procedures done:
when a T-wave abnormality is seen in an ECG ,recording is done during exercise this recording shows a biphasic or inverted T-wave.. this is an indication of narrowing of the lumen of coronary artery.. preferably an angiography is done to determine the extent of narrowing and to decide the medications..
-posted for my respected teacher Mrs.Jacquelin