- Mitral isthmus ablation is an established technique used to treat perimitral atrial flutter. The classic approach involves creating an ablation line connecting the left inferior pulmonary vein (LIPV) to the lateral mitral annulus.1 Its feasibility was first prospectively studied by Jais et al,1 who reported a high rate of bidirectional block. However, subsequent studies by the same group, as well as others, have been less promising.2 This is important because failure to achieve bidirectional block with ablation has been shown to be proarrhythmic.
- A majority of patients with structural heart disease and scar-related ventricular tachycardia (VT) have fast, hemodynamically unstable VT.1 In fact, up to one-fifth of the patients have only unstable VT, which precludes detailed activation and entrainment mapping.2 In addition, even in those with well-tolerated VT, procedural success can be complicated by acute heart failure as a consequence of prolonged episodes of induced VT and intravascular volume expansion; and one consequence of this acute decompensated heart failure is a significant increase in the short-term morbidity and mortality of the procedure.
- Percutaneous epicardial access (Figs. 1A and 1B) has gained wide acceptance as an interventional technique to access the pericardial space. Since its initial description1 in targeting epicardial circuits of ventricular tachycardia (VT) in patients with Chagasic cardiomyopathy, percutaneous epicardial access and ablation has come to play an important role in interventional electrophysiology. This technique has been recognized as a vital addition to catheter ablation of certain cardiac arrhythmias and for the delivery of newer investigational devices such as epicardial suture ligation of the left atrial appendage.