COR LOE Recommendations I B-NR In patients with symptomatic outflow tract VA in an otherwise normal heart for whom antiarrhythmic medications are ineffective, not tolerated, or not the patient s preference, catheter ablation is useful.S8.1-1 S8.1-3 I B-NR In patients with symptomatic outflow tract VT in an otherwise normal heart, a beta blocker or a calcium channel blocker is CLINICAL STATEMENTS AND GUIDELINES Recommendation-Specific Supportive Text 1. In 1 RCT, catheter ablation was superior to anti- arrhythmic medications at suppressing frequent PVCs arising from the RVOT.S8.1-4 Observational studies have shown that radiofrequency cath- eter ablation is effective in the treatment of idio- pathic VA arising from the RVOT and LV outflow Thesiteofablationmaybebelow or above the pulmonic valve in the RVOT.S8.1-9,S8.1-13 Although most RVOT VA can be ablated within the RV, 10% may require ablation within the pulmonic Serious complications are infre- quent. For LV outflow tract VA, the site of ablation below the aortic valve,S8.1-2,S8.1-6 at the aorto-mitral or on the epicardial surface of the LV summit.S8.1-3,S8.1-17,S8.1-18 The mitral and tricus- pid annulae are less common sites of idiopathic VA, but these VA can also be effectively treated with Approximately 10% of idiopathic VA may arise from the summit of the LV. Some can be ablated from the great cardiac vein or the epicardial surface, but others arise from an inaccessible region in close proximity to the left coronary artery precluding effective ablation.S8.1-14 Intramural sites of origin are infrequent but may require ablation on both the endocardial and epi- cardial surfaces of the LV ostium.S8.1-3 Complications from ablation of outflow tract VA are infrequent, but bleeding complications related to arterial and venous access, pericardial tamponade, and dam- age to the coronary arteries can occur. 2. 