An obese 43 year old man was to receive intravenous chemotherapy for lymphoma. A Hickmann line was inserted via his right internal jugular vein in preparation for this. Ten days later he presented with symptomatic sustained broad QRS complex tachycardia (panel A). After treatment with intravenous amiodarone he reverted to sinus tachycardia (panel B). Subsequently he continued to have very frequent intermittent episodes of identical tachycardia occurring several times per hour, despite continued treatment with amiodarone. Coronary and left ventricular angiography demonstrated normal coronary arteries and left ventricular function. The tip of the Hickmann line could clearly be seen to be wedged in the right ventricular cavity (panel C: to view video footage go to http://www.heartjnl.com/supplemental). The catheter was removed and there were no further episodes of tachycardia despite discontinuation of amiodarone. A 24 hour Holter monitor showed sinus rhythm throughout. The similarity of the heart rates during catheter induced ventricular tachycardia and the underlying sinus tachycardia led to variable degrees of QRS fusion and this explains the changing QRS morphology of the broad QRS tachycardia (panel A).