Catheter Ablation of Ventricular Tachycardia in Patients With MitraClip Device: Preliminary Findings
Some patients with scar‐related VT have more than one and hemodynamically nontolerated arrhythmias, and therefore are only mappable in sinus rhythm requiring a substrate‐based ablation approach in order to overcome the shortcoming of activation and entrainment mapping.9 This approach consists of identification and elimination of distinct areas of late potentials (LPs), local abnormal ventricular activities, as well as conduction channel ablation, linear isthmus ablation, electric isolation of low‐voltage area, and scar homogenization. A high‐density 3‐dimensional (3‐D) electroanatomical map of the left ventricular (LV) chamber can be achieved either by a transseptal (anterograde), a transaortic (retrograde) or combined approach as per the operator's preference. The transseptal (anterograde) approach provides an improved catheter tip‐to‐tissue contact in the anterior, apical, and lateral segments of the left ventricle compared with the retrograde approach, while the retrograde approach provides increased forces for the basal segments. These findings were shown in studies analyzing the contact force via different approaches.16 Furthermore, the region of the LV outflow tract located anterosuperior to the aortic‐mitral continuity, also so‐called “the left ventricular summit,” can be ideally accessed with a transseptal (anterograde) approach using a reversed S‐curve on the ablation catheter.18 However, it is unknown whether the implanted MitraClip device might constitute a limitation to the transmitral catheter access after transseptal puncture especially when using large steerable sheaths and novel multipolar mapping catheters, i.e., PentaRay® (Biosense Webster, Diamond Bar, CA, USA) or OrionTM (Boston Scientific, Inc, Cambridge, MA, USA) and whether this maneuver might pose the patient at higher risk for complications. Therefore, catheter access is often restricted to a retrograde transaortic approach only.
The purpose of our study is to investigate the feasibility and safety of transmitral catheter access for a successful VT ablation using steerable sheaths and multipolar mapping catheters in patients with an implanted MitraClip device.