Characterization of the electroanatomic substrate in a case of noncompaction left ventricle.

An apparently healthy 43-year-old man was submitted to cardiological evaluation for sport activity. Two-dimensional echocardiography led to suspicion of noncompaction deformity, later confirmed by magnetic resonance imaging (MRI), left ventricular catheterization and endomyocardial biopsies. To exclude life-threatening arrhythmias, the patient was submitted to an electrophysiological study and to a real-time three-dimensional electroanatomic reconstruction of left ventricle. The electroanatomic map revealed extensive area of electrical abnormalities. Extent and localization of scar areas mostly corresponded to the areas of enhancement observed at MRI. The present report is the first on electroanatomic substrate evaluation in a noncompaction left ventricle. Our findings show that ventricular noncompaction is characterized by electrical abnormalities including low voltage and scar areas, mainly related to the presence and extent of myocardial fibrosis rather than noncompacted myocardium. Electroanatomic mapping may contribute to detect and quantify fibrotic areas in patients presenting this rare cardiomyopathy.