Poster 006: Endocardial and Epicardial Ventricular Tachycardia Storm Ablation in the setting of BIVAD -Supported Cardiogenic Shock with Pulsed Field and Radiofrequency Ablation

Background: Endocardial and epicardial scar-related ventricular tachycardia (VT) ablation is reserved for select patients with refractory ventricular arrhythmias. Pulsed field ablation (PFA) is an emerging alternative robust ablation therapy typically used to treat atrial arrhythmias. PFA has selectively been utilized for ventricular arrhythmias when radiofrequency (RF) ablation yields suboptimal ablation results. However, to our knowledge, there has been no documented cases of PFA being used for ventricular arrhythmias with simultaneous biventricular mechanical circulatory support (BiV-MCS). Additionally, epicardial radiofrequency ablation in this setting has also been rarely described and is an uncommon but important manifestation of ischemic ventricular tachycardia. We present a case of successfully staged endocardial RF/PFA VT ablation combined with RF epicardial VT ablation in the setting of BIVAD-supported cardiogenic shock.

Methods: A 63-year-old man with ischemic cardiomyopathy and prior myocardial infarction presented as a life flight transfer to our center with VT storm despite antiarrhythmic therapies. The patient was brought from the helipad directly to our electrophysiology (EP) lab directly for an endocardial VT ablation which demonstrated extensive septal and apical scar. Despite immediate post-procedural success, the patient developed recurrence of VT in the advanced heart failure ICU. The patient had multivessel coronary artery disease and resultant cardiogenic shock which required biventricular mechanical support with an Impella 5.5 device and a right ventricular assist device.

Given the recurrent VT storm, the patient underwent repeat endocardial VT ablation using both radiofrequency and pulsed-field ablation techniques with excellent immediate post procedural success. However, within 48 hours, the patient developed recurrent and incessant hemodynamically significant VT. Given persistent arrhythmia burden, the decision was made to pursue combined epicardial VT ablation while supported on BIVAD. Extensive epicardial mapping identified a VT circuit originating from the left ventricular apical epicardium, and targeted radiofrequency ablation was performed with burn termination of the critical isthmus.

Outcome: In the EP laboratory, the patient exhibited recurrent, hemodynamically unstable ischemic VT consistent with prior morphologies originating from the mid-to-apical left ventricular septum and apex. Electroanatomic mapping demonstrated extensive septal and apical scar with delayed and mid-diastolic potentials, with evidence of an epicardial exit site at the left ventricular apex. Targeted PFA and RF ablation from the endocardial surface and subsequent RF ablation of the epicardial surface resulted in VT termination and subsequent non-inducibility despite aggressive programmed stimulation. Following epicardial ablation, no further sustained clinical VT occurred.

Conclusion:

Ultimately, in the setting of previous endocardial PFA/RF attempts, it was the epicardial RF VT ablation that resulted in freedom from VT storm and a successful clinical outcome that allowed for de-escalation of BiV-MCS support in the setting of cardiogenic shock. Notably, although there was concern that pulsed-field ablation energies could disrupt BIVAD function or ICD performance, PFA was delivered effectively without adverse interaction with either system.