Ventricular tachycardia, as well as ventricular fibrillation, is a leading cause of sudden cardiac death worldwide. Most people who die suddenly are not experiencing acute myocardial infarction. In fact, only 20 percent of patients who experienced sudden death suffered from acute myocardial infarction. On the contrary, 80 percent of patients who experienced sudden death had coronary artery disease. Sudden death due to ventricular tachycardia and ventricular fibrillation may also occur in any patient with an abnormal cardiac substrate. This includes patients with dilated cardiomyopathy, hypertrophic cardiomyopathy, significant valvular disease (aortic stenosis, mitral stenosis, mitral regurgitation, and pulmonic stenosis), arrhythmogenic right ventricular cardiomyopathy/dysplasia, and primary electrical disorders (such as Brugada syndrome and long QT syndrome).
When a patient presents with ventricular tachycardia, it is important to determine the stability of his or her rhythm and apply basic and advanced cardiac life support. If the patient has an unstable rhythm, advanced cardiac life support including cardiopulmonary resuscitation and early defibrillation needs to be performed immediately. Once you’ve resuscitated the patient, it is important to rule out a myocardial infarction (by serial cardiac enzymes and ECGs). A ventricular tachycardia or ventricular fibrillation that occurs in the setting of a myocardial infarction is deemed as a transient and potentially reversible problem, and is not necessarily a primary indication for an implantable cardioverter-defibrillator (ICD).