Catheter Ablation of Arrhythmias Originating From the Left Ventricular Outflow Tract.

The left ventricular outflow tract (LVOT) is a frequent source of arrhythmias in patients with and without structural heart disease. An understanding of the anatomic relationship between the aortic valvar leaflets and their supporting sinuses, coronary vessels, pulmonary arterial root, right ventricular outflow tract, and LVOT is essential for successful treatment of arrhythmias arising from this region. The juxtaposition of aortic valvar leaflet insertion into the aortic root and the crescents of myocardial tissue incorporated within the aortic sinuses of Valsalva has implications for mapping and ablation above and below the aortic valve leaflets. The presence of epicardial fat, coronary arteries, and prominent myocardium in the anteroseptal aspect of the LVOT can present unique challenges for targeting LV summit and intramural ventricular arrhythmias. Advances in ablation techniques that achieve deeper transmural lesions, combined with the knowledge of the complex LVOT anatomy and its adjoining structures, have increased success rates in targeting challenging LVOT arrhythmias.