Related Experiment Video
Updated: May 6, 2026
Robotic Ablation of Atrial Fibrillation
Published on: May 29, 2015
Stepwise Anatomical Approach to Ablation of Intramural Outflow Tract Ventricular Arrhythmias Guided by Septal
Andres Enriquez1, Haran Yogasundaram1, Victor Neira2
1Section of Cardiac Electrophysiology, Hospital of the University of Pennsylvania, Philadelphia, PA (A.E., H.Y., G.G., T.M., P.S., M.H., B.H., D.L., R.S., G.S., S.D., R.D., S.N., R.K., M.R., A.E.E., V.S., E.Z., D.C., D.F., F.M., F.G.).
Insights
A stepwise ablation approach effectively treats intramural outflow tract premature ventricular complexes (PVCs). This strategy, guided by coronary venous mapping, achieves high success rates with endocardial ablation, supplemented by ethanol infusion or bipolar ablation when necessary.
Area of Science:
- Cardiac Electrophysiology
- Interventional Cardiology
- Arrhythmology
Background:
- Intramural origin of ventricular arrhythmias is a key factor in ablation failure.
- Optimal ablation strategies for intramural outflow tract (OT) premature ventricular complexes (PVCs) remain unclear.
- This study addresses the need for effective treatment of these challenging PVCs.
Purpose of the Study:
- To investigate the efficacy of a stepwise ablation approach for intramural OT PVCs.
- To utilize mapping of the septal coronary venous system to guide ablation.
- To determine the success rate of this strategy in eliminating PVCs.
Main Methods:
- Patients with confirmed intramural OT PVCs underwent mapping of septal coronary veins.
- Radiofrequency ablation was performed from the closest endocardial site (LVOT/RVOT).
- Stepwise approach included retrograde transvenous ethanol infusion or bipolar ablation if endocardial ablation failed.
Main Results:
- Sixty patients (78% male, mean age 61 years) were included.
- Successful acute PVC suppression was achieved in all patients.
- 87% of PVCs were eliminated by endocardial ablation; ethanol infusion or bipolar ablation succeeded in the remainder.
- Long-term success (≥80% burden reduction) was 88% at 17±24 months follow-up.
- One complication of pericardial effusion occurred during venous mapping.
Conclusions:
- Most intramural OT PVCs can be successfully eliminated using endocardial ablation.
- A stepwise approach guided by intramural activation mapping yields high success rates.
- Bailout strategies like ethanol infusion are effective in a minority of cases.
Background:
The intramural site of origin is a major cause of ablation failure of ventricular arrhythmias, and the optimal strategy is unclear. This study investigated the efficacy of a stepwise ablation approach for intramural outflow tract (OT) premature ventricular complexes (PVCs) guided by mapping of the septal coronary venous system.
Methods:
Consecutive patients with OT PVCs were included, in whom an intramural origin was confirmed by demonstration of earliest activation in a septal coronary vein. Radiofrequency ablation was performed from the closest endocardial site in the left ventricular OT or right ventricular OT independent of the local activation time. If there was no suppression by endocardial ablation, then retrograde transvenous ethanol infusion with a single- or double-balloon technique was performed, targeting the earliest septal coronary vein. If venous anatomy was not suitable for ethanol ablation or if this failed, then bipolar ablation was performed.
Results:
Sixty patients (age 61±12 years; 78% men) were included. The mean QRS duration of the PVC was 150.8±17.6 ms with a maximum deflection index of 0.51±0.11, and the most common ECG pattern was a left bundle branch block with inferior axis and V3 transition (63%), followed by a right bundle branch block with inferior axis and no transition (27%). Earliest ventricular activation (28.6±11.2 ms before QRS) was recorded in the left ventricular annular vein in 15 cases and a septal perforator vein in 45 cases. Acute PVC suppression at the end of the procedure was achieved in all cases. In 87% of cases (n=52), endocardial ablation from the endocardial left ventricular OT, right ventricular OT, or both was successful in eliminating the PVC. In the remaining 8 patients, the PVC was eliminated with ethanol infusion (n=7) and bipolar ablation (n=1). Complications included one case of pericardial effusion related to venous mapping. During follow-up (17±24 months), the PVC burden was reduced from 28±12% to 2.3±4.7%, and long-term success (≥80% burden reduction) was 88%.
Conclusions:
Most intramural OT PVCs can be successfully eliminated with endocardial ablation adjacent to the earliest intramural activation site. A high success rate is achieved when following a stepwise approach, with bailout ablation strategies required in a minority of cases.
More Related Videos
06:57Ablation of Ischemic Ventricular Tachycardia Using a Multipolar Catheter and 3-dimensional Mapping System for High-density Electro-anatomical Reconstruction
Published on: January 31, 2019
10:17Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
Published on: April 11, 2025
Related Concept Videos
01:16Heart Valves
The AV valves prevent the backflow of blood from the ventricles to the atria during ventricular contraction. These valves function with the assistance of the chordae tendineae and papillary muscles. When the ventricles are relaxed, the chordae tendineae are slack, allowing blood to flow from the atria into the...
01:29Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
01:26Imbalances in Cardiac Output
CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send...