Tip to identify prolong QT interval on EKG
The QT interval is measured from the onset of the Q wave until the termination of the T wave. Various drugs can cause QT Prolongation like antiarrhythmic drugs, tricyclic antidepressants or electrolytes abnormalities such as hypokalemia, hypocalcemia or hypomagnesemia. Some clinical conditions like stroke, seizure, coma, intracerebral or brainstem bleeding, bundle branch block, infarction, and ischemia may also cause QT prolongation.
One easy way to determine QT prolongation on EKG is to find - if it clearly measures more than half the R-R interval (see diagram below)
Note: This tip may not be reliable if heart rate is more than 100 beats/minute
