Isolated ventricular noncompaction (IVNC) is a primary cardiomyopathy characterized by
a specific morphologic pattern. Patients with IVNC can develop 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
electrocardiographic (ECG) pattern at the initial diagnosis in patients with IVNC and to
investigate their correlation with the clinical features and echocardiographic findings.
Electrocardiograms from the initial diagnosis of IVNC were available for 78 patients from
March 1995 to November 2008. The most common findings were intraventricular conduction
delay (especially left bundle branch block), voltage signs of left ventricular (LV)
hypertrophy, and repolarization abnormalities. An entirely normal electrocardiogram was
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 atrioventricular block), and prolongation of the QTc and reduced systolic LV
function and LV/left atrial dilation. Moreover, patients with ECG voltage signs of LV
hypertrophy more often presented with, or had a history of, systemic embolic events. In
conclusion, our results have provided a comprehensive analysis of ECG findings of patients
newly diagnosed with IVNC. Although intraventricular conduction delay, repolarization
abnormalities, and LV hypertrophy are frequently present, no ECG patterns specific for
IVNC at the first presentation with the disease were found. Whether these findings have
prognostic implications needs to be investigated in long-term controlled studies. © 2009
Elsevier Inc. All rights reserved. (Am J Cardiol 2009;104:984 –989)