HeartMate 3- Raising New Challenges in Ablation

Aim: To describe our experience of ventricular tachycardia (VT) ablation in patients with HeartMate 3 (HM3).

Methods: Four patients with HM3 and recurrent VT that were unresponsive to medical therapy underwent 5 ablation procedures for scar related VT via trans-atrial septal approach. Prior to catheter insertion to the left ventricle (LV), an LV map was created with intracardiac echocardiography (ICE). Voltage maps were then created during sinus rhythm and inducible sustained monomorphic VTs targeted for ablation.

Results: Severe electromagnetic interference was present in the surface ECG, but not on endocardial electrograms. Hence, VT localization required analysis of intracardiac signals. Real time imaging with ICE and fluoroscopy integrated into the electroanatomic mapping system were utilized to visualize the inflow cannula, which was undistinguishable from the large pump house in LAO fluoroscopic view. Ten VTs were targeted and ablated. Six VTs were successfully mapped and targeted to the apex adjacent to the cannula. Three were mapped to mid septum and 1 was lateral basal. One patient needed 2 procedures to abolish all inducible VTs. All 4 remained arrhythmia VT free during follow up of 1-7 months.

Conclusions: VT ablation with HM3 is challenging due to significant electrical noise in the ECG. Additional imaging modalities with electro anatomical mapping was useful and avoided catheter entry into the inflow cannula. Ablation is feasible in eliminating scar related VTs in HM3 patients.