BACKGROUND: The clinical, morphological, and electrocardiographical relevance of 
delayed enhancement (DE) in cardiac magnetic resonance (CMR) was studied in 
patients with hypertrophic cardiomyopathy (HCM).
METHODS AND RESULTS: A total of 56 patients underwent both gadolinium-enhanced 
CMR and 12-lead electrocardiogram. The CMR demonstrated DE at the left 
ventricular (LV) wall in 39 patients. The patients with DE included more cases 
with dilated phase of HCM, higher New York Heart Association (NYHA) classes and 
incidence of ventricular tachyarrhythmias (VT), lower LV ejection fraction 
(LVEF) and mean LV wall thickness (WT), and a larger ratio of maximum to minimum 
LVWT. The QRS duration was prolonged and the QRS axis deviated toward left with 
increases in the DE volume (r = 0.58 and r = 0.41, P < .01). Abnormal Q waves 
were present in 5 patients and the location coincided with the DE segments in 4 
patients, but the concordance was not significant. The amplitude of T waves 
correlated with the ratio of the apex to basal LVWT (r = 0.38, P < .01) and was 
more negative in cases with DE at the apex.
CONCLUSIONS: In HCM, the DE was associated with higher NYHA classes and 
prevalence of VT, impaired global LV function and asymmetrical hypertrophy, and 
conduction disturbance, abnormal Q waves, and giant negative T waves.