Arrhythmia substrates accessible from the aortic root and immediate sub-aortic areas: Mapping and ablation

The aortic root overlies the left ventricular ostium and the interatrial septum. Muscle sleeves supporting the aortic sinuses and extensions to the inter-leaflet triangle are sources for outflow tract arrhythmias. The sinuses of Valsalva, in addition, provide access to the inter-atrial septum and left ventricular infra-aortic regions, where substrates for arrhythmias reside in both idiopathic arrhythmias and structural heart disease. This review summarizes the anatomical relationship of the aortic root to the various arrhythmic substrates and discusses approaches to ablation.