Idiopathic premature ventricular complexes originating from the ventricular outflow tract: evaluation, prognosis and management The prognosis of ventricular premature complexes (VPC) in the absence of heart disease is considered benign. VPC usually originate from the right or, less commonly, left ventricular outflow tract. QRS complexes therefore usually assume a left bundle branch block and inferior axis morphology. These VPC, particularly if very frequent (> 20,000 per day), may adversely affect left ventricular function and their suppression can restore normal function. Moreover, there is a clinical overlap with arrhythmogenic right ventricular dysplasia and this diagnosis should be considered when facing a left bundle branch block shaped VPC. However, the prognosis of outflow tract VPC is good for appropriately selected patients with normal left ventricular function, absence of syncope or ventricular tachycardia, and no evidence of cardiac disease.