Substrate guided ablation of idiopathic right ventricular outflow tract premature ventricular contractions in patients with low arrhythmia burden during the procedure

Abstract Background Ablation of premature ventricular contractions (PVCs) is currently based on activation mapping. This strategy is impaired by the absence or paucity of PVCs on the day of the procedure. Frequently, isolated diastolic potentials (DP) are present at the successful ablation site in sinus rhythm (SR), although their meaning is still a matter of debate. Objective Evaluate the feasibility and results of a substrate-based approach for ablation of idiopathic right ventricular outflow tract (RVOT) PVCs, in patients that present with a low PVC burden during the procedure. Methods We included 12 consecutive patients referred for ablation of frequent (>10000/24 hours) idiopathic PVCs from the RVOT that present with less than 2 PVCs/min in the beginning of the procedure. The ablation was based on fast mapping of the RVOT in SR looking for DPs, defined as isolated small amplitude potentials occurring after the T wave of the surface ECG in SR (Figure). The area with DPs was marked and a reduced activation mapping of the PVCs was done in that area. We evaluated the procedure time, mapping, fluoroscopy and radiofrequency (RF) application times. The number of points used for the maps, the area of DPs, local activation time and success rate. Values are presented as median (Q1-Q3). Electroanatomical mapping of the RVOT in SR was also performed in a control group of 10 subjects that underwent ablation of supraventricular arrhythmias, to evaluate the prevalence of DPs in subjects without PVCs. Results The number of PVCs during the procedure was 1 (0.1–1.6)/min. Both groups did not differ in relation to age or gender. Median age 45 (34–65) years, 6 males in the PVC group and 40 (33–65) years, 6 males in the control group, p=0.821 and p=0.231 respectively. The number of points sampled per RVOT map in SR was 400 (193–500) in the PVC group and 330 (277–425) in the control group, p=0.539. All patients in the study group had DPs in the RVOT. None of the control group subjects had DPs in the RVOT. Ablation data is presented in the Table. The acute success rate was 100%. After a median follow-up time of 4 (3–6) months one patient had recurrence. Conclusion In these group of patients with very low PVC burden during the procedure, this approach partially based on substrate mapping, made ablation of the PVCs feasible, in a fast and efficient way. Funding Acknowledgement Type of funding source: None

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Prolonged right ventricular outflow tract endocardial activation duration and presence of deceleration zones in patients with idiopathic premature ventricular contractions. Association with low voltage areas

10.22541/au.161833576.61758153/v1 ◽

2021 ◽

Author(s):

Leonor Parreira ◽

Pedro Carmo ◽

Rita Marinheiro ◽

Dinis Mesquita ◽

José Farinha ◽

...

Keyword(s):

Sinus Rhythm ◽

Right Ventricular ◽

Low Voltage ◽

Right Ventricular Outflow Tract ◽

Ventricular Outflow Tract ◽

Outflow Tract ◽

Control Group ◽

Premature Ventricular Contractions ◽

The Right ◽

Endocardial Activation

Background and aims: Activation wavefront is rapid and uniform in normal myocardium. Fibrosis is associated with deceleration zones (DZ) and late activated zones. Our aim was to study the right ventricular outflow tract (RVOT) endocardial activation duration (EAD) in sinus rhythm, and assess the presence of DZs, in patients with PVCs and controls. Methods: We studied 29 patients with idiopathic PVCs from the outflow tract, subjected to catheter ablation and an activation and voltage map of the RVOT in sinus rhythm. A control group of 15 patients without PVCs that underwent ablation of supraventricular arrhythmias was also studied. The RVOT EAD and number of 10 ms isochrones were assessed. DZ were defined as a zone with>3 isochrones within 1 cm radius. Low voltage areas (LVA) defined as areas with local electrogram amplitude <1.5mV. Results: The two groups did not differ in relation to age, gender or number of points in the map. EAD and number of 10 ms isochrones were higher in the PVC group; 56 (41-66) ms vs 39 (35-41) ms, p=0.001 and 5 (4-8) vs 4 (4-5), p=0.001. Presence of DZs and LVAs were more frequent in the PVC group; 20 (69%) vs 0 (0%), p<0.0001 and 21 (72%) vs 0 (0%), p<0.0001. Patients with LVAs had longer EAD 60 (52-67) vs 36 (32-40) ms, p<0.0001. Conclusions: EAD was longer and DZs were more frequent in patients with PVCs and were associated with presence of LVAs.

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Prolonged Right Ventricular Outflow Tract Endocardial Activation Duration and Presence of Deceleration Zones in Patients With Idiopathic Premature Ventricular Contractions. Association With Low Voltage Areas

Frontiers in Physiology ◽

10.3389/fphys.2021.699559 ◽

2021 ◽

Vol 12 ◽

Author(s):

Leonor Parreira ◽

Pedro Carmo ◽

Rita Marinheiro ◽

Dinis Mesquita ◽

José Farinha ◽

...

Keyword(s):

Right Ventricular ◽

Low Voltage ◽

Right Ventricular Outflow Tract ◽

Propagation Speed ◽

Ventricular Outflow Tract ◽

Outflow Tract ◽

Control Group ◽

Premature Ventricular Contractions ◽

Wavefront Propagation ◽

Endocardial Activation

Background and AimsThe wavefront propagation velocity in the myocardium with fibrosis is characterized by the presence of deceleration zones and late activated zones, that are absent in the normal myocardium. Our aim was to study the right ventricular outflow tract (RVOT) endocardial activation duration in sinus rhythm, and assess the presence of deceleration zones, in patients with premature ventricular contractions (PVCs) and in controls.MethodsWe studied 29 patients with idiopathic PVCs from the outflow tract, subjected to catheter ablation that had an activation and voltage map of the RVOT in sinus rhythm. A control group of 15 patients without PVCs that underwent ablation of supraventricular arrhythmias was also studied. RVOT endocardial activation duration and number of 10 ms isochrones across the RVOT were assessed. Propagation speed was calculated at the zone with the higher number of isochrones per cm radius. Deceleration zones were defined as zones with >3 isochrones within 1 cm radius. Low voltage areas were defined as areas with local electrogram with amplitude <1.5 mV.ResultsThe two groups did not differ in relation to age, gender or number of points in the map. RVOT endocardial activation duration and number of 10 ms isochrones were higher in the PVC group; 56 (41–66) ms vs. 39 (35–41) ms, p = 0.001 and 5 (4–8) vs. 4 (4–5), p = 0.001. Presence of deceleration zones and low voltage areas were more frequent in the PVC group; 20 (69%) vs. 0 (0%), p < 0.0001 and 21 (72%) vs. 0 (0%), p < 0.0001. The wavefront propagation speed was significantly lower in patients with PVCs than in the control group, 0.35 (0.27–0.40) vs. 0.63 (0.56–0.66) m/s, p < 0.0001. Patients with low voltage areas had longer activation duration 60 (52–67) vs. 36 (32–40) ms, p < 0.0001, more deceleration zones, 20 (95%) vs. 0 (0%), p < 0.0001, and lower wavefront propagation speed, 0.30 (0.26–0.36) vs. 0.54 (0.36–0.66) m/s, p = 0.002, than patients without low voltage areas.ConclusionRight ventricular outflow tract endocardial activation duration was longer, propagation speed was lower and deceleration zones were more frequent in patients with PVCs than in controls and were associated with the presence of low voltage areas.

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P5702Non-invasive epicardial and endocardial mapping in patients with idiopathic right ventricular outflow tract premature ventricular contractions: new insights into arrhythmia substrate

European Heart Journal ◽

10.1093/eurheartj/ehz746.0644 ◽

2019 ◽

Vol 40 (Supplement_1) ◽

Author(s):

A L Parreira ◽

P Carmo ◽

P Adragao ◽

J Pinho ◽

R Jeronimo ◽

...

Keyword(s):

Right Ventricular ◽

Right Ventricular Outflow Tract ◽

Ventricular Outflow Tract ◽

Outflow Tract ◽

Control Group ◽

P Value ◽

Premature Ventricular Contractions ◽

Non Invasive ◽

Endocardial Mapping ◽

Unipolar Electrograms

Abstract Background It has been accepted for years that idiopathic premature ventricular contractions (PVCs) with origin in the right ventricular outflow tract (RVOT) are benign. They are thought to result from triggered activity and most studies do not describe abnormal findings during electroanatomical mapping Dispersion of ventricular repolarization is associated with the susceptibility to ventricular arrhythmias and may indicate the presence of diseased myocardium. The activation recovery interval (ARI) has been used as a surrogate measure of ventricular action potential duration and refractory period. Purpose The aim of this study was to use the new non-invasive epicardial and endocardial mapping system (NEES) to study patients with RVOT PVCs in order to evaluate the ARI in the epicardium of RVOT during sinus rhythm (SR). Methods Non-invasive mapping was performed with the NEES, based on body surface electrocardiograms of a maximum of 224 electrodes and computed tomography imaging data. Unipolar electrograms were reconstructed on the epicardial and endocardial surfaces. Patients were excluded if they had structural heart disease, previous ablation or conduction abnormalities. ARI was defined as the interval between times of minimum derivative of the QRS and the maximum derivative of the T wave in the unipolar electrograms. We evaluated the ARI map in patients with RVOT PVCs and in a control group of patients without PVCs (Figure). We assessed the maximum value of ARI (Max ARI), the minimum value of ARI (Min ARI) and the difference between the Max ARI and the Min ARI (Diff ARI). Results We studied 8 patients with RVOT PVCs and 8 patients without PVCs. The results are presented in the table. Demographic and NEES data RVOT PVCs (n=8) Control (n=8) P value* Demographic data Age in years, median (IQR) 53 (48–65) 59 (52–67) 0.536 Male gender, n (%) 4 (50) 6 (75) 0.608 NEES data Max ARI in msec, median (IQR) 285 (236–331) 228 (197–298) 0.195 Min ARI in msec, median (IQR) 176 (138–192) 216 (185–255) 0.161 ARI diff in msec, median (IQR) 111 (83–147) 15 (4–34) <0.0001 NEES map Conclusion In this group of patients we found a significantly higher dispersion of the ARI measurements through the epicardium of the RVOT in patients with PVCs in comparison with patients without PVCs.

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Investigating Origins of Ventricular Arrhythmia Arising from Right Ventricular Outflow Tract and Comparing Initial Ablation Strategies

10.22541/au.162119273.39478712/v1 ◽

2021 ◽

Author(s):

Zhi Jiang ◽

LIU Qifang ◽

Ye Tian ◽

Yidong Zhao ◽

Wei Liu ◽

...

Keyword(s):

Right Ventricular ◽

Success Rate ◽

Right Ventricular Outflow Tract ◽

Ventricular Outflow Tract ◽

Outflow Tract ◽

Limited Data ◽

Clinical Trial Registry ◽

Qualitative Interaction ◽

Curve Method ◽

Activation Mapping

Background The origin distribution of right-ventricular-outflow-tract (RVOT) ventricular arrhythmias (VAs) remains unclear. There is limited data on the ablation effectiveness of the reversed U-curve method compared with the antegrade method. Objectives To investigate the origin distribution of RVOT-type VAs and compare the ablation effectiveness of the two methods. Method Consecutive patients who had idiopathic RVOT-type VAs were prospectively enrolled. After activation mapping, patients were randomly assigned to supravalvular strategy using the reversed U-curve or subvalvular strategy using the antegrade method. The primary outcome was initial ablation (IA) success, defining as the successful ablation within the first three attempts. Results 61 patients were enrolled from November 2018 to June 2020. Activation mapping revealed 34/61 (55.7%) of the earliest ventricular activating (EVA) sites were above the pulmonary valves (PVs). The IA success rate was 25/33(75.8%) in the patients assigned to supravalvular strategy as compared with 16/28(57.1%) in those assigned to subvalvular strategy (P=0.172). Logistic regression revealed a substantial and qualitative interaction between the EVA sites and IA strategies (Pinteraction<0.001). For multiple-comparison, either strategy had a remarkably higher IA success rate in treating its ipsilateral EVA sites than contralateral ones (P<0.0083). Conclusion Of the idiopathic RVOT-type VA origins, half were located above the PV. The two strategies did not differ in the primary outcomes. However, they complement locating the EVA sites and facilitate ipsilateral ablation, which produces a significantly higher IA success rate. (Chinese Clinical Trial Registry number, ChiCTR2000029331)

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Investigating Origins of Ventricular Arrhythmia Arising From Right Ventricular Outflow Tract and Comparing Initial Ablation Strategies

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.727546 ◽

2021 ◽

Vol 8 ◽

Author(s):

Zhi Jiang ◽

Qifang Liu ◽

Ye Tian ◽

Yidong Zhao ◽

Wei Liu ◽

...

Keyword(s):

Clinical Trial ◽

Right Ventricular ◽

Success Rate ◽

Right Ventricular Outflow Tract ◽

Ventricular Outflow Tract ◽

Outflow Tract ◽

Clinical Trial Registry ◽

Clinical Trial Registration ◽

Qualitative Interaction ◽

Activation Mapping

Background: The origin distribution in right ventricular outflow tract (RVOT) ventricular arrhythmias (VAs), as well as the initial ablation effectiveness of reversed U-curve method and antegrade method, remains unclear.Objectives: To investigate the origin distribution of RVOT-type VAs and compare the initial ablation effectiveness of the two methods.Method: Consecutive patients who had idiopathic RVOT-type VAs were prospectively enrolled. After activation mapping, patients were randomly assigned to supravalvular strategy using the reversed U-curve or subvalvular strategy using the antegrade method. The primary outcome was initial ablation (IA) success, defined as the successful ablation within the first three attempts.Results: Sixty-one patients were enrolled from November 2018 to June 2020. Activation mapping revealed that 34/61 (55.7%) of the earliest ventricular activating (EVA) sites were above the pulmonary valves (PVs). The IA success rate was 25/33 (75.8%) in the patients assigned to supravalvular strategy as compared with 16/28 (57.1%) in those assigned to subvalvular strategy (p = 0.172). Multivariate analysis revealed a substantial and qualitative interaction between the EVA sites and IA strategies (pinteraction < 0.001). Either strategy had a remarkably higher IA success rate in treating its ipsilateral EVA sites than contralateral ones (p < 0.0083).Conclusion: Of the idiopathic RVOT-type VA origins, half were located above the PV. The supravalvular and subvalvular strategies did not differ in IA success rates. However, they were complementary to reveal the EVA sites and facilitate ipsilateral ablation, which produces a significantly higher IA success rate.Clinical Trial Registration: Chinese Clinical Trial Registry number, https://www.chictr.org.cn/showproj.aspx?proj=45623, ChiCTR2000029331.

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