Idiopathic Ventricular Arrhythmias

Idiopathic ventricular arrhythmias (VAs) occur with a mechanism that is unrelated to myocardial scar. Idiopathic VAs most commonly occur in patients without structural heart disease, but can occur in those with structural heart disease. Idiopathic VAs present as a sustained or a non-sustained ventricular tachycardia or premature ventricular contractions. Imaging examinations such as echocardiography, nuclear tests, and cardiac magnetic resonance imaging are helpful for excluding any association of an idiopathic VA occurrence with myocardial scar. For the past two decades, the sites of idiopathic VA origins, commonly endocardial but sometimes epicardial, have been increasingly recognized. Idiopathic VAs usually originate from specific anatomical structures and exhibit characteristic electrocardiograms based on their anatomical background. Idiopathic VAs are basically benign, but they require medical treatment or catheter ablation when idiopathic VAs are symptomatic, frequent, or cause tachycardia-induced cardiomyopathy. This book chapter describes the up-to-date information on the prevalence of idiopathic VA origins relevant to the anatomy, diagnosis, and treatment of idiopathic VAs

Pulmonary Vein Isolation with a Multielectrode Basket Catheter

Pulmonary vein (PV) isolation (PVI) techniques have evolved as a curative treatment of atrial fibrillation (AF) since PVI guided by circumferential mapping with a circular catheter was initially proposed. A multielectrode basket catheter (MBC) is also useful for PVI because of some advantages; (1) an MBC provides some information about the PV anatomy on the fluoroscopic image, (2) an MBC can utilize the non-fluoroscopic navigation system, (3) an MBC enables the direct three-dimensional mapping around the PV ostium and antrum, (4) the distal electrodes of the MBC can be used to monitor some activation changes within the PV in real time and thereby indicate the effects of ablation at the ostium and antrum as radiofrequency lesions are created. PVI with an MBC is an effective and safe procedure to cure AF by integrating the PV anatomy and electrophysiology in combination with a non-fluoroscopic three-dimensional navigation system for the ablation catheter