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Percutaneous epicardial mapping during ablation of difficult accessory pathways as an alternative to cardiac surgery
Miguel Valderrábano1, David A Cesario, Sen Ji
1UCLA Cardiac Arrhythmia Center, Division of Cardiology, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
Insights
Percutaneous epicardial mapping aids in successful ablation of accessory pathways (APs) when endocardial approaches fail. This combined technique offers an alternative to surgery for complex cases.
Area of Science:
- Cardiology
- Electrophysiology
- Minimally Invasive Procedures
Background:
- Radiofrequency (RF) catheter ablation for accessory pathway (AP)-mediated tachycardias can fail.
- Cardiac surgery is the only alternative for failed RF ablations.
- A combined epicardial-endocardial approach is investigated for refractory APs.
Purpose of the Study:
- To define the role of percutaneous epicardial mapping in ablating previously failed accessory pathways.
- To evaluate a combined percutaneous epicardial and endocardial approach for complex AP ablations.
Main Methods:
- Retrospective analysis of 6 cases with failed prior accessory pathway ablations.
- Utilized conventional endocardial mapping followed by percutaneous epicardial mapping via subxiphoid approach when needed.
- Compared epicardial and endocardial electrograms, applying RF energy to both sites as necessary.
- Assessed coronary artery proximity via arteriography.
Main Results:
- Epicardial mapping assisted in identifying successful ablation sites in all cases.
- Successful ablation was achieved with epicardial RF in 2 patients.
- Endocardial ablation was successful after epicardial mapping in 4 patients.
- These 6 patients represented 18% of referred cases with failed AP ablations.
Conclusions:
- A combined endocardial-epicardial approach facilitates successful endocardial ablation in most cases.
- Epicardial RF delivery is effective in selected cases of refractory accessory pathways.
- Percutaneous epicardial mapping is a viable alternative to cardiac surgery for failed AP ablations.
Objectives:
The aim of this study was to define the role of percutaneous epicardial mapping for the ablation of previous failed ablation of accessory pathways.
Background:
Cardiac surgery is the only curative option for failed radiofrequency (RF) catheter ablation of accessory pathway (AP)-mediated tachycardias. We investigated a combined percutaneous epicardial and endocardial approach for failed AP ablations.
Methods:
We present our experience in a series of 6 cases (7 APs) with previous failed attempts at catheter ablation (median 2 attempts, range 1-4) and persistent symptomatic tachycardias. Endocardial mapping of the APs was performed using conventional techniques. Sites with local electrograms suggestive of AP location were selected. When initial endocardial mapping was not successful for ablation of the pathway, percutaneous transthoracic pericardial puncture was performed via a subxiphoid approach, and an ablation catheter was positioned at the epicardial aspect of the putative AP location for epicardial-endocardial electrogram comparison. Endocardial RF energy was applied to locations considered appropriate. Epicardial RF applications were delivered when endocardial applications failed. Coronary arteriography was performed to assess the proximity of coronary arteries to the ablation catheter.
Results:
APs were located in the right free wall (4 patients, 5 APs) and the right (1 patient) and left (1 patient) posteroseptal regions. In all patients, epicardial mapping assisted in identifying successful ablation sites. In 3 patients, the earliest atrial activation during orthodromic tachycardia was present in an epicardial electrogram. Successful AP ablation was achieved with an epicardial RF application in 2 patients, either alone or with simultaneous endocardial-epicardial delivery. In the remaining 4 patients, APs were successfully ablated endocardially after epicardial mapping. These patients represent 18% of all cases referred to our institution for ablation of previously failed accessory pathways (6/32 patients).
Conclusions:
A combined endocardial-epicardial approach to mapping and RF ablation can facilitate successful endocardial ablation in most cases. In selected cases, APs can be ablated by epicardial delivery of RF. Epicardial mapping is an effective alternative to cardiac surgery for patients in whom prior attempts at AP ablation have failed.
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