Elimination of Local Abnormal Ventricular Activities: A New End Point for Substrate Modification in Patients With Scar-Related Ventricular Tachycardia
Does radiofrequency catheter ablation (RFCA) of local abnormal ventricular activity (LAVA) recorded during sinus rhythm (SR) prevent scar-related ventricular tachycardia (VT)?
Seventy patients (mean age 67 years) with sustained VT and ischemic or nonischemic cardiomyopathy underwent high-density mapping with a multi-arm mapping catheter during SR. LAVA was defined as high-frequency potentials during or after the far-field ventricular electrogram in SR. RFCA was performed to eliminate the LAVAs. Implantable cardioverter-defibrillator arrhythmia logs or Holter monitors were used to assess long-term efficacy.
Left ventricular endocardial mapping was performed in all patients and epicardial mapping was performed in 21/70 patients. LAVAs were found in 67/70 patients (96%). In 4 patients, the LAVAs were only epicardial. The median delay between the ventricular electrogram and the LAVA was 80 ms. RFCA successfully eliminated the LAVAs in 47/67 patients (70%). At a median follow-up of 22 months, recurrent VT or death occurred significantly more often in patients without LAVA elimination (75% and 20%, respectively) than in patients with LAVA elimination (32% and 19%, respectively). LAVA elimination was the only factor significantly associated with a lower risk of recurrent VT/death.
The authors concluded that LAVAs are present in almost all patients with scar-related VT, and their elimination by RFCA is associated with improved clinical outcomes.
Conventional mapping of scar-related VT is not feasible when the VT results in rapid hemodynamic deterioration. In such cases, either pace mapping, circumferential scar ablation, or ablation of a surrogate marker such as LAVAs or isolated diastolic potentials is necessary. LAVAs most likely are generated by surviving myocardial fibers that serve as a substrate for VT within areas of scar.
Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Heart Failure and Cardiac Biomarkers
Keywords: Follow-Up Studies, Hemodynamics, Tachycardia, Ventricular, Cicatrix, Biological Markers, Endocardium, Cardiomyopathies, Diastole, Catheter Ablation, Defibrillators, Implantable, Epicardial Mapping
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