Ventricular extrasystoles masquerading as aberrantly conducted atrial extrasystoles because of postectopic T wave...

This presentation reflects a case where broad and bizarre premature QRS complexes are preceded by sinus beats whose T wave is "abnormal," and seems to contain a premature P wave. A diagnosis of atrial extrasystoles with aberrancy thus could be entertained. The extrasystoles, however, are ventricular in origin. The pattern is explained on the basis of postectopic T wave change, that is, the change in configuration of the T wave that occurs in the sinus beat after an extrasystole.