**2. Who should be considered to perform the epicardial approach?**

### **2.1 Contraindication for endocardial approach**

Generally, the endocardial approach was contraindicated in the following condition


In the patient with the presence of newly-identified mural thrombus, the strategy of endocardial ablation should be postponed. Previous report described the results of endocardial VT ablation in 8 patients with identified old thrombus [15]. Intracardiac echocardiography (ICE) seems to be more sensitive for the detection of LV thrombi compared to transthoracic echocardiography (TTE) and is helpful in real-time navigation of the mapping / ablation catheter. No procedural or periprocedural complications were observed in this retrospective study [15].

Mechanical prosthetic aortic and mitral valves preclude either a retrograde aortic or transseptal approach to the left ventricle (LV) endocardium. Several operators have reported previously on the use of unconventional techniques during VT ablation such as transventricular septal puncture, [16, 17] epicardial approach, [18] transmechanical valve approach, [19] transcoronary venous approach, [20] or transapical approach [21].

#### **2.2 Contraindication for percutaneous epicardial approach**

Intrapericardial access is usually obtained through a subxiphoidal pericardial puncture. This approach might not be possible in patients with pericardial adhesions caused by prior cardiac surgery, pericarditis, or prior epicardial ablation. (**Figures 1** and **2**) In such cases, a hybrid procedure involving surgical access to

*Epicardial Radiofrequency Ablation: Who, When, and How? DOI: http://dx.doi.org/10.5772/intechopen.99824*

#### **Figure 1.**

*Epicardial puncture in a patient with prior epicardial ablation. The figure showed the anterior–posterior view during epicardial puncture. The fluoroscopic view demonstrated the contrast stasis in the bottom of the epicardium due to prior ablation and severe adhesion. The wire could not advance further in the localized epicardial space.*

#### **Figure 2.**

*Epicardial puncture in a patient with prior coronary artery bypass grafting. The figure showed the anterior– posterior view during after an initial puncture. The fluoroscopic view demonstrated the contrast stasis in the bottom of the epicardium due to prior cardiac surgery severe adhesion. The wire could not advance further in the localized epicardial space (panel A). After several attempts, the ablation catheter was advanced to the limited epicardial space. Coronary angiography was done before the ablation to avoid coronary injury through the graft (panel B).*

a subxiphoid pericardial window or lateral thoracotomy might be a feasible and safe method of performing epicardial catheter ablation in the electrophysiology laboratory [4].

## **2.3 Endocardial approaches were more favorable than epicardial approach**
