Voltage combined with pace mapping is simple and effective for ablation of noninducible premature ventricular contractions originating from the right ventricular outflow tract

Abstract

Background Premature ventricular contractions (PVCs) from the right ventricular outflow tract (RVOT) can resist conventional mapping strategies. Studies regarding optimal mapping and ablation methods for patients with noninducible RVOT‐PVCs are limited. We retrospectively evaluated the efficacy and safety of a novel mapping strategy for these cases: voltage mapping combined with pace mapping. Hypothesis Methods We retrospectively included symptomatic patients (n = 148; 76 males; age, 44.5 ± 1.4 years) with drug‐refractory PVCs originating from the RVOT, who underwent radiofrequency catheter ablation (RFCA), and stratified them as Group 1 and Group 2. Group 1 patients had noninducible RVOT‐PVCs, determined after programmed stimulation, burst pacing, and isoproterenol infusion (n = 21; 12 males; age, 39.5 ± 10.8 years). Group 2 patients had inducible PVCs. Group 1 patients were subjected to voltage mapping combined with pace mapping; Group 2 underwent conventional mapping. In all patients prior to RFCA, detailed 3‐dimensional electroanatomic voltage maps of the RVOT were obtained during sinus rhythm using the CARTO system. Results Patients from both groups had similar success and complication rates associated with the RFCA. In Group 2, 89% (113/127) experienced the earliest and the successful ablation points in the voltage transitional zone. During the follow‐up (36 ± 8 months), patients from both groups suffered similar rates of PVC relapse (2/21 and 7/127, respectively; P = 0.826). Conclusions Voltage mapping combined with pace mapping is effective and safe for patients with noninducible RVOT‐PVCs determined by conventional methods.

Right ventricular outflow tract low‐voltage areas identify the site of origin of idiopathic ventricular arrhythmias: A high‐density mapping study

“…Second, a relatively small number of patients with low‐arrhythmia burden has been included for analysis. Third, abnormal local bipolar electrograms during sinus rhythm were defined as those displaying an amplitude of less than 1 mV, which is different from previous studies . However, we do believe that these thresholds are dependent on the electrode size and spacing.…”

“…Previous studies have addressed whether low bipolar voltage areas represent potential targets for ablation in patients with idiopathic RVOT VAs. Sampling 104 ± 11 points for RVOT electronatomical mapping, Wang et al have shown that the SOO is located in low‐voltage areas (amplitude < 0.5 mV) in 3% of patients, in transitional voltage zone (amplitude between 0.5 and 1.5 mV) in 89% of patients, and in high‐voltage areas (amplitude > 1.5 mV) in 8% of patients. Yamashina et al have demonstrated that the majority of idiopathic RVOT VAs are successfully ablated in the transitional voltage zone (amplitude between 0.5 and 1.5 mV) and 4.2% in the low‐voltage zone (<0.5 mV) .…”

“…However, c‐MRI may lack sensitivity in identifying substrate abnormalities in the right ventricle . Data regarding electronatomical abnormalities in successful ablation sites of idiopathic RVOT VAs are limited and based on low resolution mapping . We hypothesized that high‐density endocardial bipolar voltage mapping during sinus rhythm may detect minimal electrical abnormalities within the RVOT that possibly represent the arrhythmogenic substrate and therefore targets for successful catheter ablation.…”

Electrophysiological characteristics of the earliest activation site in idiopathic right ventricular outflow tract arrhythmias under mini‐electrode mapping

“…Studies have demonstrated that the origins of RVOT VAs are located in the voltage transition zone . Even in the patients with sparse clinical VAs during the EP examination, transition voltage mapping combined with pacing mapping could achieve considerable ablation success .…”

“…RVOT VAs often originate from the transitional‐voltage zone beneath the pulmonary valve or the myocardial extensions of PSCs . At times, the low‐amplitude local near‐field origin potential could be obscured by large far‐field potentials of the surrounding myocardium.…”