Idiopathic malignant premature ventricular contractions.

The presence of premature ventricular contractions (PVCs) in patients with structurally normal hearts was once considered a benign phenomenon. However, in susceptible patients, these "benign" or idiopathic PVCs may develop malignant potential and trigger ventricular fibrillation and result in sudden cardiac death. Alternatively, idiopathic PVCs can also induce cardiomyopathy. Clinical recognition of these entities can lead to effective targeted therapy. In the first instance, treatment consists of ablating the PVC source and implanting a defibrillator, whereas in the second scenario, ablating the PVC origin can normalize left ventricular function.