Ventricular Arrhythmias

Ventricular arrhythmias are common in all forms of heart disease and are an important cause of cardiac arrest and sudden death. Many ventricular arrhythmias are benign but may serve as a marker for underlying disease or its severity. Others are life threatening. The significance of an arrhythmia is determined by the specific characteristics of the arrhythmia and the associated heart disease, and these features guide evaluation and therapy. This review discusses various mechanisms and types of ventricular arrhythmias and management based on clinical presentation (including patients with symptomatic arrhythmia and increased risk of sudden death without arrhythmia symptoms). Genetic arrhythmia syndromes, such as abnormalities of repolarization and the QT interval, catecholaminergic polymorphic ventricular tachycardia (VT), and inherited cardiomyopathies, are discussed in depth. Under the rubric of management of ventricular arrhythmias, drug therapy for ventricular arrhythmias, implantable cardioverter-defibrillators (ICDs), and catheter ablation for VT are also covered. Tables chart out guideline recommendations for ICD therapy, drugs for the management of ventricular arrhythmias, and indications and contraindications for catheter ablation of ventricular arrhythmias. Electrocardiograms are provided, as well as management algorithms for ventricular arrhythmias based on patient presentation, and an algorithm for identifying patients with systolic heart failure and left ventricular ejection less than or equal to 35% who are candidates for consideration of an ICD for primary prevention of sudden cardiac death. This review contains 5 figures, 8 tables, and 61 references. Keywords: Ventricular arrhythmias, implanted cardioverter-defibrillator (ICD), Ventricular tachycardia (VT), Premature Ventricular Contractions (PVC), Myocardial Infarction (MI), Brugada syndrome, Arrhythmogenic right ventricular cardiomyopathy (ARVC), electrocardiographic (ECG)