Table 7.
Rationale of hybrid ablation of atrial fibrillation
| Creation of completed lines |
|---|
| 1. Surgical approach may be more complete in making transmural ablation lines |
| (a) Ablation tools are designed for making lines |
| (b) Smooth epicardial surface ideal for surgical tools |
| (c) Visual imaging reveals the atrial surface, ablation lines, and gaps in lesions |
| 2. Catheter ablation may be most effective in targeting specific lesions |
| (a) Catheter ablation is designed to create point lesions |
| (b) Catheter ablation can slip off endocardial ridges, or trabeculations, thus breaking up lines |
| (c) Even with ultrasound imaging, assessing continuing of endocardial lesions may be difficult |
| Complementary nature of epicardial and endocardial ablation |
| 1. Epicardial ablation |
| (a) Heat sink of the circulating blood in the atrial chamber limits depth |
| (b) Epicardial lesions may be limited by fat |
| (c) Depth of ablation lesions may be insufficient |
| (d) May fail to penetrate the endocardium |
| 2. Endocardial ablation |
| (a) Creating transmural lesions may be difficult |
| (b) Endocardial ablation may result in collateral damage to anatomic structures |
| Together these techniques complement each other! |
| Role of mapping |
| 1. Epicardial mapping may be limited |
| (a) Constrained by pericardial reflections |
| (b) Absence of sophisticated tools and mapping systems designed for epicardial use |
| (c) Epicardial fat may limit mapping |
| 2. Endocardial mapping |
| (a) Extensive experience in mapping |
| (b) Large range of tools and technology |
| (c) Formally trained |
| (d) Mature enabling technology |
| Together these techniques complement each other! |
| 2. Unique targets |
| (a) Surgical epicardial ablation |
| (i) Full division of ligament of Marshall |
| (ii) LAA removal division |
| (iii) Targeted ganglionic plexi ablation |
| (iv) Safer superior vena cava isolation |
| (b) Transcatheter endocardial ablation |
| (i) More effective cavotricuspid isthmus line |
| (ii) Atrial flutter and atrial tachycardia ablation |
| (iii) Coronary sinus ablation |
| (iv) Map for flutter |
| (v) Mapping techniques, such as FIRM and CFAE |
| Together these techniques complement each other! |
CFAE indicates complex fractionated atrial electrograms; FIRM focal impulse and rotor modulation; and LAA left atrial appendage
Reproduced from reference (61) with permission