Abstract

Isolated ventricular noncompaction (IVNC) is a primary cardiomyopathy characterized by a specific morphologic pattern. Patients with IVNC may suffer from various arrhythmic complications such as life-threatening ventricular arrhythmias, as well as heart failure or systemic embolic events. The present study was designed to comprehensively analyze the ECG pattern at the time of initial diagnosis in patients with IVNC, and to investigate their correlation with clinical features and echocardiographic findings. ECGs from the time of initial diagnosis of IVNC were available in 78 patients between March 1995 and November 2008. The most common findings were intraventricular conduction delay (especially left bundle branch block), voltage signs of left ventricular (LV) hypertrophy, and repolarisation abnormalities. An entirely normal ECG was only present in 10 subjects (13%). However, no ECG findings or patterns specific for IVNC were found. A striking overlap was observed between the presence of intraventricular conduction delay (left bundle branch block, in particular), atrial conduction delay (PR interval prolongation or AV-block), and prolongation of the QTc on the one hand, and reduced systolic LV function and LV / left atrial dilation on the other. Moreover, patients with electrocardiographic voltage signs of LV hypertrophy more often presented with or had a history of systemic embolic events. In conclusion, our study provides a comprehensive analysis of ECG findings of patients newly diagnosed with IVNC; while intraventricular conduction delay, repolarisation abnormalities and LV hypertrophy are frequently present, no ECG patterns are specific for IVNC at the time of first presentation with the disease. Whether these findings indeed have prognostic implications needs to be investigated in long-term controlled studies.