LEE Sang-Chol, CHANG Shin Yi, KIM Mi Hyun, CHANG Sung A, PARK Sung Ji, PARK Seung Woo, CHOE Yeon Hyeon, OH Jae K.

Sang-Chol LEE, Shin Yi CHANG, Mi Hyun KIM, Sung A CHANG, Sung Ji PARK, Seung Woo PARK, Yeon Hyeon CHOE, Jae K. OH

Cardiovascular Imaging Center, Samsung Medical Center/Sungkyunkwan University School of Medicine, Korea

キーワード :

Background: Hypertrophic cardiomyopathy （HCM） is a disease that affects the myocardium and results in irregular alignment of the thickened myocardial fibers and mutilation that can lead to internal scarring and fibrosis. Echocardiography has been the method of choice for diagnosing and assessing the severity of HCM, and diastolic dysfunction has been thought to be one of the hallmarks in HCM. Cardiac magnetic resonance imaging （CMR） has been proven to be useful in depicting myocardial fibrosis, and previous reports have suggested that diastolic dysfunction is related to myocardial fibrosis. We sought to find out if this is actually the case.
Methods: Two hundred and thirty-three consecutive patients with HCM diagnosed by echocardiography received CMR on the same day of the echocardiogram. Clinical characteristics, echocardiographic variables, and CMR variables including the presence and degree of delayed enhancement （DE） were evaluated and analyzed comparatively.
Results: Mean age of the subjects was 54.4±12.2 years and the gender ratio was M:F = 181:52. There were 82 subjects showing a septal type of HCM, 64 apical type, 30 concentric type, and 57 mixed type. DE on CMR was found in 215 subjects （92.3％）. On univariate analysis, Presence of DE was associated with various echocardiographic parameters such as increased LV mass index, wall thickness ratio, and septal wall thickness. None of the diastolic parameters such as E or A velocity, E/A ratio, IVRT, e’ velocity, E/e’ ratio or left atrial volume index were associated with presence of delayed enhancement. Multivariate analysis revealed only the LV mass index to be independently associated with DE on CMR.
Conclusion: Myocardial fibrosis depicted by delayed enhancement on cardiac MRI does not seem to reflect diastolic dysfunction or increased LV end-diastolic pressure. The relationship of LV wall thickness and LV mass with myocardial fibrosis may explain the long-term risk of hypertrophy in HCM patients.