The most common causes of ventricular fibrillation are ischemic heart disease, such as coronary artery disease, acute infarction, especially in acute anterior interstitial infarction, or in acute extensive anterior wall infarction. There are also hypertrophic obstructive cardiomyopathies and arrhythmogenic right ventricular cardiomyopathies. There are also ion channelopathies such as long QT syndrome and Brugada syndrome that present with ventricular fibrillation. In addition ventricular fibrillation occurs in severe electrical shock injury, severe hypoxia, ischemia, and preexcitation syndromes combined with atrial fibrillation with very fast ventricular rate. Others are antiarrhythmic drugs, especially those that cause QT interval prolongation with tip reversal. Ventricular fibrillation also occurs when there are severe electrolyte disturbances, such as severe hypokalemia and hyperkalemia.