RESUMO
Monomorphic premature ventricular contractions (PVCs) are a benign phenomenon in patients without structural heart disease. The focal source is usually localised in the right ventricular outflow tract and more rarely in the left ventricular outflow tract. We report two cases of frequent isolated PVCs treated with radiofrequency catheter ablation. Ventricular dysfunction was documented in one patient and the potential contribution of arrhythmia to ventricular dysfunction was suspected. In both patients electroanatomic mapping of the right and left ventricular outflow tracts was performed, which allowed identification of the earliest ventricular activation during PVCs. The site of the earliest ventricular activation was documented in both cases at the left coronary cusp of the aortic valve. Aortography was performed to disclose the relationship between the ablation catheter and the anatomic structure of the aortic root. PVCs were successfully eliminated with radiofrequency application in both patients.