The aim of the present study was to determine the predictors of adequate intraprocedural premature ventricular complex (PVC) frequency for successful mapping and ablation of idiopathic PVCs.

A total of 101 consecutive patients (45 men; age: 47.9 ± 14.2 years) who had undergone idiopathic PVC ablation between 01 November 2018 and 24 June 2020 constituted our study population. Clinical and demographic data, procedural details and 24 h rhythm recordings that had been recorded before the procedure were retrospectively evaluated. Total PVC burden and diurnal variability assessed by the ratio of night time (22:00–06:00) over day time (06:00–22:00) PVC burden was calculated. Patients were classified into three groups based on the relationship between hourly PVC number and HR. If there was a significant positive correlation between hourly PVC number and corresponding hourly HR, patients were classified into the fast HR-PVC group. If there was a significant negative correlation between hourly PVC number and corresponding hourly HR, patients were classified into the slow HR-PVC group. Patients were classified into the independent HR-PVC group if there was no significant correlation between hourly PVC number and corresponding hourly HR. Clinical characteristics and Holter parameters were compared between groups with and without adequate intraprocedural frequency of PVCs that permitted activation mapping.

In all, 74 patients had frequent intraprocedural PVC that permitted activation mapping (Group 1) and 27 patients (26.7%) had infrequent intraprocedural PVCs which necessitated isoproterenol infusion or cancellation of ablation procedure (Group 2). PVC burden was significantly higher in the group with frequent intraprocedural PVCs (26.1 ± 9.4% vs 21.2 ± 10.3%; p: 0.026). There were no significant differences between groups regarding the relationship between hourly PVC number and heart rate (Fast HR-PVC 42 (56.8%) vs 18 (66.6%); slow HR-PVC  4(5.4%) vs 3 (11.1%); independent HR PVC 28 (37.8%) vs 6 (22.2%) in the respective order for group 1 and group 2; p: 0.26) or the ratio of night/day PVC burden (median 0.99 (IQR 0.4) vs median 0.83 (IQR 0.54) in the respective for group 1 and group 2 ; p: 0.53). Binary logistic regression analysis revealed the 24 h Holter PVC burden as the sole parameter that is significant predictor of frequent intraprocedural PVCs permitting activation mapping. A Holter PVC burden ≥ 19.43% had 72% sensitivity and 60% specificity for the prediction of sufficient intraprocedural PVCs that permitted activation mapping and ablation (area under the curve: 0.65; p: 0.02)

The 24 h PVC burden was the only predictor of adequate intraprocedural PVC frequency permitting activation mapping during idiopathic PVC ablation.