Mapping and Ablation of Premature Ventricular Complexes

Authors, Journal, Affiliations, Type, DOI

• Andres Enriquez MD, Daniele Muser MD, Timothy M. Markman MD, Fermin Garcia MD
• JACC: Clinical Electrophysiology, Vol. 10, No. 6, June 2024, pp. 1206–1222
• Section of Cardiac Electrophysiology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
• State-of-the-Art Review
• DOI: https://doi.org/10.1016/j.jacep.2024.02.008

Overview

This state-of-the-art review from the University of Pennsylvania EP group provides a comprehensive update on PVC catheter ablation indications, ECG localization, mapping techniques, ablation energy sources, and site-specific ablation strategies. Catheter ablation has become first-line therapy for symptomatic PVCs, PVC-induced cardiomyopathy, and PVC-triggered VF. Significant progress in mapping technology (multielectrode catheters, ECGI) and novel energy sources (PFA, stereotactic radioablation) has expanded ablation feasibility, including challenging intramural and LV summit substrates.

Keywords

Catheter ablation; mapping; premature ventricular complexes; ventricular arrhythmias

Key Takeaways

Indications for Catheter Ablation

• PVCs are common: prevalence 1% on 12-lead ECG, 40–75% on 24–48h Holter; usually benign without structural disease
• Symptomatic PVCs: HRS Class I for RVOT, tricuspid/mitral annulus, AMC, moderator band, papillary muscle PVCs; Class IIa for LVOT, LV summit, parahisian; ESC Class I for RVOT or fascicular PVCs, Class IIa for other locations
• PVC-induced cardiomyopathy: Most cases occur with PVC burden >10%; PVC burden >24% has ~80% sensitivity/specificity for LVEF reduction; risk factors include broad QRS (>150 ms), interpolated PVCs, epicardial origin, long exposure, lack of symptoms; ABC-VT risk score (Axis, Burden, Coupling interval, nonsustained VT) predicts adverse events
  • Ablation success rate 65–90%; LVEF normalises in 82% after ablation (Bogun et al.)
  • Class I/IIa recommendation; ablation reasonable if burden >20% in asymptomatic patients with preserved LVEF (Class IIb)
• PVC-triggered VF (short-coupled VF): Accounts for 6.6–7.8% of aborted cardiac arrest; coupling interval <350 ms; triggers from LV/RV Purkinje system in majority; ablation freedom from VF ~89% (Haïssaguerre multicenter, n=27); Class IIa
• CMR detects LGE in 16% of apparently idiopathic PVCs; associated with malignant arrhythmic events

ECG Localization of PVCs

• RBBB pattern → LV origin; LBBB pattern → RV or interventricular septum
• Narrow QRS → septal origin; wider QRS → free wall
• Inferior axis (positive II/III) → outflow tract or superior AV valves; superior axis → inferior ventricle
• Precordial transition: RBBB — later transition = more basal; LBBB — later transition = more toward RV free wall
• RVOT: LBBB, inferior axis, transition V3–V4 (septal) or V4–V5 (free wall); pulmonary artery PVCs have larger R in inferior leads and greater aVL/aVR ratio
• LV summit: RBBB or LBBB with early V2/V3 transition, taller R in III vs II, more negative aVL vs aVR, pseudo-delta wave or MDI >0.55; V2 pattern break (abrupt loss of R in V2 vs V1/V3) is characteristic
• Parahisian: LBBB, V2–V3 transition, R in I and aVL, narrow QRS, lead II more positive than III
• Moderator band: LBBB, left superior axis, late transition (>V4), possible inferior lead discordance
• LV Purkinje: Narrow QRS (<130 ms), rsR' in V1 (RBBB-like), initial Q in lead I; posterior fascicle = left superior axis; anterior fascicle = right inferior axis

PVC Mapping

• Activation mapping (preferred when PVCs present): Earliest activation >30 ms pre-QRS onset predicts successful ablation; multielectrode catheters (PentaRay, OctaRay, HD Grid, IntellaMap Orion) allow rapid high-resolution mapping; limitations include requirement for frequent PVCs and far-field signal confusion
• Pace mapping (complementary, or sole strategy when PVC burden is low): 11/12 or 12/12 leads visual match = good pace map; automated algorithms (PASO on CARTO, Score Map on Ensite); spatial resolution 1.8 cm² vs 1.2 cm² for activation; achieves success in 79–80% when used exclusively; unreliable for fascicular PVCs due to far-field capture
• ECGI (CardioInsight): Noninvasive body-surface electrode vest + CT/CMR geometry; 96% accuracy for outflow tract VAs; distance from true site of origin ~22.6 mm in re-entrant VT; role in guiding stereotactic radioablation when catheter ablation fails
• Indicators of intramural origin: Earliest endo/epicardial activation <−20 ms pre-QRS; similar activation timing in different chambers (within 10 ms); diffuse early activation; earliest activation in septal coronary vein; suboptimal pace maps at sites of earliest activation; late or transient PVC suppression with recurrence

Ablation Energy Sources

• RF ablation: Standard; irrigated tip preferred; strategies for deep/intramural substrate: modified irrigation (half-normal saline or 5% dextrose), simultaneous unipolar ablation, bipolar ablation, retractable needle catheter, impedance modulation with repositioned dispersive patch
• Cryoablation: Preferred for parahisian PVCs (reversible cryomapping at −30°C); enhanced catheter stability for papillary muscle PVCs (ice adherence); minimal thrombus formation; initial −30°C for 20 s, then −75°C for 4 min if PVC suppression without AV block
• Retrograde coronary venous ethanol ablation: For LV summit and intramural septal PVCs inaccessible to catheter; balloon occlusion of septal vein branch; preferred over transarterial approach (avoids arterial cannulation risks); 1 mL ethanol per injection over 1–2 min
• Stereotactic radioablation: ECGI-guided; for PVCs refractory to catheter ablation, high procedural risk, or inaccessible sites (e.g., mechanical valve prostheses)
• Pulsed field ablation (PFA): Nonthermal electroporation; tissue-selective (cardiomyocyte-specific); minimal heat generation; robust evidence in AF but ventricular PFA experience is still limited

PVC Sites of Origin

RVOT and Pulmonary Artery

• ~70% of idiopathic VAs arise from RVOT + LVOT; LVOT proportion is increasing in recent series
• Septal RVOT more common than free wall; ICE reveals many RVOT-morphology PVCs arising from pulmonary artery myocardial sleeves
• Retroflexed catheter approach; deflectable sheath recommended; irrigated catheter 20–35 W; coronary angiogram if ablating above left pulmonary cusp (proximity to left main/LAD)

LV Ostium (Aortic Cusps, Subaortic LVOT, Mitral Annulus, AMC)

• RBBB with positive precordial concordance; multiphasic QRS in V1 = LCC; qR in V1 = AMC; monomorphic R in V1 = anterolateral mitral annulus
• Retrograde aortic access with long femoral sheath (SL1 or SR0); trans-septal if significant aortic calcification or mechanical aortic valve (Agilis sheath); pace mapping less reliable in LV ostium
• Irrigated catheter 20–45 W; extended RF (>2 min, up to 5 min) for intramural cases; coronary angiogram mandatory for cusp or venous ablation

LV Summit

• Anatomically bounded by LAD and LCx; accessible region (inferior/lateral, RBBB, ablatable via coronary veins or endocardium) vs inaccessible region (superior/septal, LBBB with V2–V3 transition)
• If endocardium-to-earliest-epicardial distance <14 mm → endocardial ablation preferred; >14 mm → coronary venous ablation first
• Comprehensive mapping required: GCV/AIV (epicardial), septal perforator veins (intramural), endocardial LVOT; retrograde ethanol as escalation; percutaneous epicardial only in accessible region

LV Papillary Muscles

• Posteromedial PM: RBBB, left or right superior axis, V3–V5 transition
• Anterolateral PM: RBBB, right inferior axis, V3–V5 transition, possible inferior lead discordance
• Retrograde aortic or transseptal access; activation mapping preferred; Purkinje potential at successful ablation site; cryoablation as RF bailout (enhanced catheter stability)

LV Purkinje System

• ~4% of idiopathic PVCs; most common trigger of idiopathic VF; mechanism: abnormal automaticity or triggered activity (not re-entry, unlike fascicular VT)
• Earliest fascicular potential (FP) is the mapping target — not earliest ventricular electrogram; FP-V interval shorter than sinus rhythm = electrode proximal to or in a different fascicular branch
• Retrograde aortic approach; map left-sided His, LBB, LAF, LPF with multipolar catheter; monitor AV conduction and QRS width during RF; solid tip catheter 30–50 W usually sufficient

Cardiac Crux and Inferoseptal LV

• Basal crux: LBBB, left superior axis, V2 transition, QS in inferior leads, MDI >0.55
• Inferoseptal LV: RBBB, initial R in inferior leads, narrow QRS, MDI <0.55
• Map middle cardiac vein (MCV); irrigated catheter 10–30 W; coronary angiogram always required; percutaneous epicardial access if no early activation in MCV or endocardium

Parahisian Region

• Earliest activation within 10 mm of His electrogram; risk of AV block with RF
• Systematic mapping of RV septum, RCC/NCC, LV septum, RA; target earliest bipolar activation ≥5 mm from largest His potential
• RF at 10–20 W uptitrated to 30–35 W; immediate termination if AH prolongation, junctional rhythm, RBBB, or transient heart block; cryoablation preferred if optimal site has visible His potential

Tricuspid Valve

• 8–9% of idiopathic VAs; always LBBB; septal sites (early transition, narrow QRS, QS in V1) vs free wall (late transition, wide QRS, rS in V1)
• Catheter stability challenging; deflectable sheath essential; retroflexed or superior vena cava approach

Moderator Band and RV Papillary Muscles

• MB PVCs are a common source of malignant PVCs triggering VF; LBBB, left superior axis, late transition >V4
• Purkinje potential at successful ablation site; ablation often requires multiple points along MB/papillary muscle
• Cryoablation advantageous: better stability, reduced ablation-induced ectopy

Intramural PVCs

• ~20% of LVOT PVCs; ~45% of suspected LV summit PVCs; no pathognomonic ECG features
• Diagnosis made at EP study; map septal perforator veins to confirm intraseptal origin
• Stepwise escalation: extended RF → modified irrigation → impedance modulation → simultaneous unipolar → bipolar ablation → needle catheter → ethanol → stereotactic radioablation

Outcomes of PVC Ablation

• Large multicenter series (n=1,185, 8 centers, 2004–2013): 84% acute success; 71% long-term freedom from PVCs without AADs, 85% with AADs; major complications 2.4% (groin 1.3%, cardiac tamponade 0.8%, AV block 0.1%)
• Single-center series (n=682 outflow tract VAs, 16 years): 86% acute success, 10% required repeat ablation; complications 2.3%
• RVOT origin = only independent predictor of success; epicardial origin + multifocal PVCs = predictors of failure

Limitations of the Document

• State-of-the-art review; reflects single-center (U Penn) technique preferences, not a systematic review
• Outcomes data from registry series; no RCTs comparing ablation strategies by PVC site
• Ventricular PFA data limited; ECGI accuracy for non-outflow-tract PVCs not well established
• Limited prospective outcome data for intramural strategies (ethanol, stereotactic radioablation)

Key Concepts Mentioned

• concepts/PVC-Induced-Cardiomyopathy — central indication; ABC-VT risk score; reversibility with ablation
• concepts/PVC-Mapping-Ablation — comprehensive mapping and ablation technique review
• concepts/Pulsed-Field-Ablation — emerging PFA modality for ventricular arrhythmias
• concepts/Late-Gadolinium-Enhancement — CMR detects concealed structural disease in 16% of apparently idiopathic PVCs
• concepts/Electrical-Storm — PVC-triggered VF (short-coupled VF) context

Key Entities Mentioned

• entities/ARVC — epicardial PVCs as marker; intramural substrate context
• entities/DCM — PVC-induced cardiomyopathy as reversible DCM mimic

Wiki Pages Updated

• wiki/sources/PVC-ablation-jaccep-2024.md — created
• wiki/sourceindex.md — updated
• wiki/wikiindex.md — updated
• wiki/concepts/PVC-Induced-Cardiomyopathy.md — created
• wiki/concepts/PVC-Mapping-Ablation.md — created
• wiki/concepts/Pulsed-Field-Ablation.md — updated