The ‘double transition’: a novel electrocardiogram sign to discriminate posteroseptal accessory pathways ablated from the right endocardium from those requiring a left-sided or epicardial coronary venous approach

ConclusionThe combination of a q wave in V1 with a double QRS transition pattern in the precordial leads is highly specific of a right endocardial AP and rules out the need for CS or left-sided mapping.
Source: Europace - Category: Cardiology Source Type: research