Background: Full diastolic pathway recording has been associated with a high rate of VT termination during radiofrequency ablation. The role of diastolic pathway mapping on VT recurrence has yet to be clearly elucidated.
Objective: Explore the role of diastolic pathway activation mapping on VT recurrence.
Methods: Patients who underwent VT ablation guided by high-density mapping (EnSite, Advisor HD Grid) were enrolled. During activation mapping, the presence of electrical activity in all segments of diastole defined the evidence of having recorded the full diastolic interval. Patients were categorized as having recorded the full diastolic pathway, partial diastolic pathway, or no map. Recurrences of VT were defined as appropriate ICD therapies or ECG-documented arrhythmia.
Results: 67 patients were included. The complete recording of the diastolic pathway was achieved in 29/67 patients. A partial recording of the diastolic pathway was achieved in 21/67 patients. No activation map was recorded in 17/67. At 18 months, freedom from VT recurrence after the last ablation procedure was 62% in the overall cohort. At 18 months, freedom from VT recurrence was 89%, 42%, and 49% in patients who had full diastolic activity recorded, partial diastolic activity recorded or underwent substrate modification, respectively; the difference between the groups was statistically significant (p=0.01).
Conclusion: Mapping the full diastolic pathway was associated with higher freedom from VT recurrence as compared to partial pathway recording and substrate modification. Targeted mapping of diastolic activity may help predict VTs employing layered circuits and further optimize ablation strategies.