Management of PVC-Mediated Ventricular Fibrillation from RVOT Lateral Wall
This 71-year-old woman requires immediate ICD implantation for secondary prevention of sudden cardiac death, followed by catheter ablation of the triggering PVC from the RVOT lateral wall to prevent recurrent VF episodes and ICD shocks. 1
Immediate Life-Saving Intervention
ICD implantation is the mandatory first step with a Class I, Level B recommendation for all survivors of idiopathic VF, regardless of whether the triggering PVC can be eliminated. 1 This takes absolute priority because PVC-mediated VF carries high mortality risk and ablation alone—while highly effective—cannot guarantee complete prevention of future episodes.
Catheter Ablation Strategy
Primary Recommendation
Catheter ablation of the triggering PVC is strongly recommended (Class I, Level B) specifically for patients with PVC-triggered recurrent VF leading to ICD interventions or electrical storm. 1 The European Society of Cardiology explicitly states this indication for experienced operators, with long-term success rates of 82% (defined as absence of VF, polymorphic VT, or sudden cardiac death) after >5 years follow-up. 1
Critical Technical Considerations for RVOT Lateral Wall Location
High complication risk at this specific site: The RVOT free wall (lateral wall) carries a documented risk of RVOT rupture, though rare, making this location particularly hazardous compared to septal RVOT sites. 1
Mapping strategy: Begin with activation mapping and/or pace-mapping during electrophysiology study at the RVOT lateral wall site. 1 If the triggering PVC is not spontaneously present during the procedure, use stored ICD electrograms to analyze the morphology and timing of far- and near-field recordings to guide pace-mapping at likely trigger sites. 2
Success rates are excellent: Acute RVOT PVC/VT catheter ablation success rates exceed 95% when performed by experienced operators, though long-term follow-up data remain limited. 1
Procedural Timing and Prerequisites
Document the PVC morphology with pre-interventional 12-lead Holter ECG if spontaneous PVCs are not present during the procedure, as this guides ablation targeting. 1
The procedure relies on PVC presence during the electrophysiology study, ideally occurring after a VF episode or during VF storm when ectopy is most frequent. 1
Ablation should only be performed in highly experienced centers given the anatomical complexity and specific risks of lateral RVOT wall perforation. 1
Role of Antiarrhythmic Drugs
Limited Utility in This Context
Beta-blockers and Class III antiarrhythmics may reduce but rarely prevent recurrent VF episodes in patients with PVC-triggered VF. 1
For standard RVOT VT/PVC without VF, catheter ablation is recommended after failure of antiarrhythmic drug therapy (e.g., beta-blocker), but in your patient with established VF, the threshold for ablation is much lower given the life-threatening nature. 1
Sodium channel blockers (Class IC agents) are specifically recommended for LVOT/aortic cusp origins, not RVOT origins like your patient. 1
Critical Safety Measures
Power titration is essential at the lateral RVOT wall to minimize perforation risk, using conventional energy delivery. 1
Maintain stable catheter contact during ablation; very-high-power, very-short-duration (90W/4s) techniques show promise for RVOT PVCs with reduced tissue trauma and procedural time, though this remains investigational. 3
Common Pitfalls to Avoid
Do not delay ICD implantation waiting for ablation results—the ICD is mandatory regardless of ablation success. 1
Do not use calcium channel blockers as first-line therapy for wide-complex tachycardia of unknown origin in this setting, as they are potentially harmful. 4, 5
Do not assume the PVC origin is septal RVOT based on ECG alone—the lateral wall location requires specific mapping confirmation and carries different risks. 1
Avoid multiple VF inductions during the procedure when possible; use stored ICD electrograms and pace-mapping strategies to minimize dangerous VF episodes. 2