Incessant non-sustained ventricular tachycardia immediately after MitraClip placement: a case report.

Background: MitraClip therapy has become an alternative therapy for primary and secondary mitral regurgitation (MR) in patients at high surgical risk. However, this procedure is associated with several complications.

Case summary: The patient was a 93-year-old male with severe MR caused by prolapse of the mid-posterior mitral leaflet (P2) and atrial enlargement. His heart failure (HF) continued to worsen, requiring hospitalization. Considering his high surgical risk, the heart team chose MitraClip treatment. After one clip was placed in the centre of the mitral valve (P2 lateral side), MR severity was reduced from severe to trivial. However, immediately after grasping, incessant non-sustained ventricular tachycardia (VT) with a heart rate of 150 beats/min occurred. Since there were no significant ST-T changes on electrocardiogram and no left ventricular (LV) wall motion abnormalities on echocardiography, ischaemic heart disease was ruled out, and pacing with a temporary pacemaker, potassium level correction, and intravenous amiodarone administration were performed. The frequency of VT decreased but it did not disappear. Diuretics were administered for HF, and VT disappeared within a few hours, with no recurrence, probably due to a decrease in the LV chamber size after diuresis.

Discussion: The VT waveform showed a right bundle branch block pattern with a superior axis. Furthermore, a negative lead I and a transition zone with an abrupt change from V4 to V5 indicated that PVC/VT arose from the posterior papillary muscle area. The probable cause was mechanical extension of the posterior medial papillary muscle as a result of leaflet grasping, with resolution following appropriate volume management.