[Arrhythmias with normal heart rate]

Arrhythmias with ventricular rate between 60-100/min are discussed. Premature ventricular complex is considered to be a risk factor for sudden cardiac death and sustained ventricular tachycardia under some particular conditions, especially after myocardial infarction. To improve the prognosis of patients with ventricular arrhythmias, many trial were performed. Ventricular arrhythmia hypothesis was based on the thought that the patients' prognosis would be improved by suppression of ventricular arrhythmias with antiarrhythmic agents. However, CAST study showed unexpected results. Recently, some investigators suggest that antiectopic action and antifibrillatory action are different and empiric therapy with amiodarone is reported. Other arrhythmias with normal heart rate are considered to have little risk for survival. Then antiarrhythmic therapy should be based on quality of life.