Intraventicular Conduction Defect comment: The ECG is in sinus rhythm and the QRS is markedly widened with a QRS duration of 260ms. The QRS seems split and gives the impression of ventricular bigemini but note that the second QRS deflection that looks like a PVC is in fact 200 ms after the onset of the first part of the QRS and hence too early for a PVC. Of interest this patient has recurrent ventricular tachycardia which may relate to his grossly widened QRS. The progression of the block can be seen over a three year period. comment from the web: When presented as a puzzler the correct interpretation of this ECG was not received, only suggestions of ventricular bigemini where given.