- 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.
- This article describes our current practice, clinical outcomes, and future directions for the use of balloon cryoablation for the treatment of atrial fibrillation.
- 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.
- Electrophysiology laboratories commonly use closely spaced bipolar recordings for mapping. However, unipolar recordings have some useful features that can provide additional complimentary information, provided the limitations of these recordings and the particular recording techniques are recognized.
- Radiofrequency catheter ablation has become the treatment of choice for patients with symptomatic Wolff-Parkinson-White syndrome (WPW). The QRS complex morphology present on the 12-lead electrocardiogram (ECG) in WPW patients depends on the location of the accessory pathway(s) (AP) and the degree of fusion over the normal atrioventricular (AV) conduction. Accordingly, it is determined by the site of ventricular insertion of the accessory pathway, AV node conduction time, and atrial conduction.
- Percutaneous atrial fibrillation (AF) ablation using catheter-delivered radiofrequency energy continues to improve in safety and effectiveness. Nonetheless, the potential risk of esophageal injury often limits the ability to fully ablate the posterior portion of the left atrium to achieve optimal procedural success without complications. We present a comprehensive approach that addresses this challenge. Our ablative strategies include (1) identifying the esophagus to minimize ablative energy, when possible, in the proximity of the esophagus, (2) maximize the ability of the esophagus to remove heat and to heal from potential thermal injury, and (3) optimizing energy delivery to avoid deep tissue injury while maintaining procedural efficacy.
- With the rapid evolution of atrial fibrillation ablation procedures, electrophysiologists have necessarily strived for simple and anatomic-based approaches. In all except the most straightforward procedures, however, questions regarding the significance of various potentials recorded on mapping and ablation catheters arise.1,2 Other articles in this series have described in detail the various approaches to atrial fibrillation ablation. In this article, the anatomic and electrophysiologic bases for pacing maneuvers used with a variety of ablation approaches are reviewed.