Premature ventricular contractions (PVCs) are usually benign and do not cause a significant problem. Treatment is aimed at symptoms reduction (although most people with frequent PVCs are actually asymptomatic, unlike out patient). Beta-blockers or non-dihydropyridine calcium channel blockers (diltiazem or verapamil) can be used to suppress the PVCs. Rarely are antiarrhythmic drugs such as mexilitine needed. Lastly, PVCs can be ablated, however this procedure is not always simple. Some electrophysiologists believe that there is a subset of patients in whom frequent PVCs (such as ventricular bigeminy lasting for months) can cause a cardiomyopathy resulting in systolic congestive heart failure, thus aggressive treatment should be undertaken. PVCs can occur after myocardial infarction, however it was shown int he CAST trial that suppressing them with antiarrhythmic drugs actually increased mortality and thus once again, they are thought to be benign.