- 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.
- Advances in cardiac care of the young have given rise to a growing and aging population of patients with congenital heart disease. Despite remarkable improvements in overall survival, sudden cardiac death remains the most common cause of late mortality. As a result, implantable cardioverter-defibrillators (ICDs) are increasingly used in this heterogeneous patient population. Tetralogy of Fallot and transposition of the great arteries are the most prevalent subtypes of congenital heart disease in ICD recipients.
- Tetralogy of Fallot is the most common form of cyanotic heart disease, accounting for approximately 10% of congenital heart defects. Corrective surgery involves atrial and/or ventricular incisions and patches that, when combined with altered hemodynamics, predispose to the late onset of arrhythmias.1,2 In a multicenter cohort followed up for 35 years after corrective surgery, sustained atrial and ventricular tachyarrhythmias occurred in 10% and 12% of patients, respectively.1 Macroreentrant right atrial tachycardia is the most common atrial arrhythmia.
- In this two-part series, we discuss the anatomical basis for arrhythmias arising above the semilunar valves. In this part (part I), we describe the relevant anatomy and technique for mapping and ablation of ventricular arrhythmias arising above either the pulmonic or the aortic valve. After an initial discussion of the underlying anatomy and characteristics of the substrate targeted for ablation above the semilunar valve, an approach for safe and effective ablation of supravalvar ventricular arrhythmias is presented.
- Electroanatomic mapping refers to the acquisition and display of electrical information combined with spatial localization. Technologies presently available include both contact and noncontact electroanatomic mapping. This review focuses on the creation and proper interpretation of contact electroanatomic maps, which involves the sequential recording of unipolar or bipolar electrograms with a catheter in contact with the endocardium or epicardium and display of this information on a three-dimensional navigation system.