Background: Diastolic dysfunction is common in patients with overt hypertrophic cardiomyopathy (HCM). Steady-state cine magnetic resonance imaging (MRI) enables measurement of the diastolic function of the left ventricle (LV), and late gadolinium enhanced MRI can delineate the presence and extent of fibrosis in HCM. The purpose of this study was to determine the relationship between the extent of myocardial fibrosis demonstrated by late gadolinium-enhanced MRI and diastolic dysfunction.
Methods and results: Seventeen patients (13 men, mean age 57.7+/-9.8 years) with HCM were studied. The severity index of late gadolinium enhancement was determined by scoring the extent of enhanced tissue in 30 myocardial segments. The peak filling rate (PFR), LV ejection fraction and LV mass were determined by cine MRI. Contrast-enhanced MRI demonstrated late gadolinium enhancement in 97 of 510 segments (19%) and 13 of the 17 patients (77%). The severity index of late gadolinium enhancement demonstrated a significant negative correlation with PFR (r= -0.86, p<0.01) and with the LV ejection fraction (r= -0.59, p<0.05). No significant correlation was observed between the severity index of late gadolinium enhancement and LV mass (r=0.23, p=0.30).
Conclusion: The extent of myocardial fibrosis revealed by late gadolinium-enhanced MRI has a strong relationship to diastolic dysfunction in patients with HCM.