When the delta wave is negative, it may simulate the abnormal Q waves caused by a myocardial infarction. The table shown here illustrates that when the ventricles are pre-excited by an impulses traveling down a left lateral bypass tract, the delta wave may be negative in leads I and aVL, simulating a lateral wall infarction. When the bypass tract is in a left posterior or posterior-septal location, the delta wave will be negative in leads III and aVF, simulating an inferior wall infarction.