Ventricular Tachycardia Ablation With Pulsed-Field Ablation — Three-Case Series (2023)

Authors, Journal, Affiliations, Type, DOI

• Authors: Cristina Lozano-Granero, Jun Hirokami (joint first authors), Eduardo Franco, Shota Tohoku, Roberto Matía-Francés, Boris Schmidt, Antonio Hernández-Madrid, José Luis Zamorano Gómez, Javier Moreno, Julian Chun
• Journal: JACC: Clinical Electrophysiology 2023;9(9):1990–1994
• Affiliations: University Hospital Ramón y Cajal / CIBERCV, Madrid; Cardioangiologisches Centrum Bethanien (CCB), Frankfurt
• Type: Case series (3 patients, 2 centres), "Innovations in Clinical Electrophysiology" section
• DOI: 10.1016/j.jacep.2023.03.024

Overview

The first multicentre series of ventricular tachycardia ablation with a pulsed-field ablation catheter designed for atrial use — a 31-mm pentaspline Farawave catheter and Farastar generator delivering 2.0 kV bipolar applications. All three cases had structural heart disease and were ablated during tachycardia or over a mapped region of interest; the tachycardia terminated in two, a new dense bipolar scar appeared at every treated site, and no patient recurred over 4–6 months. The instructive failure is case 3: after twelve endocardial applications in arrhythmogenic cardiomyopathy created a dense but ineffective lesion, epicardial mapping still showed late potentials and mid-diastolic activity, and only epicardial radiofrequency terminated the arrhythmia — direct evidence that pentaspline PFA does not reliably reach an epicardial circuit even across the thin right ventricular wall. The series is hypothesis-generating only, but it set the agenda for every subsequent ventricular PFA study: whether depth, not energy, is the limiting factor.

Keywords

Pulsed-field ablation; ventricular tachycardia

Key Takeaways

Rationale for PFA in the ventricle

• Proximity-dependent rather than contact-dependent delivery may suit trabeculated and unstable sites such as papillary muscles.
• Absence of lesion scar contraction may avoid the ventricular impairment that follows extensive RF substrate homogenisation.
• Applications last seconds, which improves catheter stability and shortens the procedure; absence of coagulum or char may reduce thromboembolic complications.
• Preclinical swine work (Koruth; Im) had shown deep, homogeneous lesions with partial preservation of the endothelium, arterioles, nerve fascicles and pericardial connective tissue, and preserved effectiveness within and around infarcted substrate.
• A first-in-human scar-VT case had already been published (Ouss et al.).

Case 1 — mappable VT, small substrate

• 83-year-old man with non-obstructive coronary disease (prior circumflex PCI), preserved ejection fraction, RBBB-morphology superior-axis sustained monomorphic VT; ablation offered as an alternative to ICD implantation.
• LV voltage map showed preserved voltages with tiny isolated late potentials in the mid-apical lateral wall; pace map matched over a relatively large area; VT not inducible.
• 9 bipolar 2.0 kV applications (trains of four biphasic microsecond pulses), basket configuration. Local electrogram loss after the first application; loss of pace capture after the third.
• Post-ablation voltage map showed new dense scar (<0.5 mV) at the application sites. No complications; no recurrence at 6 months.

Case 2 — LV aneurysm, VT storm, bail-out

• 83-year-old woman with a large inferolateral apical LV aneurysm, VT storm (cycle length 520 ms) with multiple ICD therapies including degeneration to VF with ATP, on amiodarone and mexiletine, two prior futile 3D-mapping-guided ablations.
• Extensive late potentials in sinus rhythm and mid-diastolic potentials during VT across the aneurysm; pace map matched the clinical VT.
• 18 bipolar 2.0 kV applications in different configurations and rotations during VT; VT terminated after the fifth application and was rendered non-inducible. No complications; no recurrence at 5 months.

Case 3 — the instructive failure

• 69-year-old man with biventricular arrhythmogenic cardiomyopathy and electrical storm on sotalol (amiodarone previously not tolerated); incessant VT of suspected RV origin (negative QRS in all precordial leads).
• Endocardial RV voltage map showed low voltage (<1.5 mV) in the basal inferolateral free wall with concordant late potentials, so the planned epicardial approach was deferred.
• VT mechanically induced on advancing the catheter; a presystolic potential at −20 ms was found superiorly, and two applications there failed; two further applications slightly inferior terminated VT.
• 12 applications in total created a new dense scar (<0.1 mV) — but electrical stimulation reinduced the tachycardia.
• Epicardial mapping then showed late potentials opposite the endocardial target and mid-diastolic fragmented activity (the isthmus). A single 40 W RF application during VT terminated it; after extensive epicardial substrate elimination VT was non-inducible. No recurrence at 4 months.

Operative learning points

• Lesion depth is the binding constraint. In this series a basket PFA catheter achieved a maximal lesion depth of 6.0 ± 1.2 mm in scarred ventricular tissue; the authors attribute both the preserved electrogram amplitude and the failure to eliminate an epicardial circuit to absent transmurality.
• Electrogram attenuation is modest — mean bipolar amplitude fell 30% after the first application and 56% after a complete set (1.35 → 0.93 → 0.59 mV in sinus rhythm; 0.83 → 0.59 → 0.36 mV during VT) — consistent with a lesion that does not span the wall, leaving far-field signal.
• Repetition dependence: every case needed multiple applications either to eliminate late potentials and lose pace capture or to terminate tachycardia, supporting cumulative lesion growth with consecutive applications.
• Catheter handling inside the LV was limited but workable, with frequent ectopy while deploying to basket or flower configurations.
• VT termination during PFA may reflect direct capture of a large myocardial mass beyond the target, not elimination of the circuit — so termination alone is not proof of efficacy.

Limitations of the document

• Three patients, no control, no systematic follow-up. A case series in the "innovations" format; selection, operator technique and substrate vary between cases.
• Off-label use of an atrial catheter and waveform. The pentaspline 31-mm catheter and 2.0 kV bipolar dosing were designed for pulmonary vein isolation; nothing here validates a ventricular dose.
• Anecdotal endpoints. Freedom from recurrence over 4–6 months is too short and too few patients to estimate efficacy, and ICD interrogation is the only monitoring described.
• No imaging or histology of the ventricular lesions. Depth is inferred from electrogram behaviour and prior preclinical data.
• The favourable cases may reflect small substrates. Case 1 had preserved voltages and a tiny target; case 2 was a bail-out of an aneurysm that RF had already failed to control.

Key Concepts Mentioned

• concepts/Ventricular-PFA — the energy modality
• concepts/Ventricular-PFA — the ventricular application this series opened
• concepts/VT-Ablation — procedural context and endpoints
• concepts/Epicardial-VT-Ablation — the approach case 3 ultimately required
• concepts/VT-Ablation-Nonischemic-Cardiomyopathy — arrhythmogenic cardiomyopathy substrate
• entities/ARVC — case 3's underlying disease

Key Entities Mentioned

• Farawave pentaspline catheter and Farastar generator (Farapulse)
• PentaRay mapping catheter and Carto3 (Biosense Webster)
• Thermocool SmartTouch (Biosense Webster)
• University Hospital Ramón y Cajal, Madrid; Cardioangiologisches Centrum Bethanien, Frankfurt

Wiki Pages Updated

• Created: wiki/sources/pfa-vt-case-series-jacep-2023.md
• Updated: wiki/concepts/Ventricular-PFA.md
• Updated: wiki/concepts/Pulsed-Field-Ablation.md, wiki/concepts/Epicardial-VT-Ablation.md
• Updated: wiki/sourceindex.md, wiki/wikiindex.md, log.md