Khảo sát đặc điểm hình ảnh bắt thuốc thì muộn trên cộng hưởng từ của bệnh cơ tim phì đại

SUMMARY

Objective: To describe the characteristics of hypertrophic cardiomyopathy on Magnetic resonance imaging; to evaluate the loacation, pattern and extent of late gadolinium enhancement (LGE); to evaluate the relationship among left ventricular function, end diastolic wall thickness and LGE about pattern and extent.

Materials and Methods: Cine imaging and delayed enhancement imaging were performed in 27 patients with HCM on a 3 Tesla MRI unit (Siemens Verio) at the University Medical Center Hospital between January 2016 and June 2020. Global left ventricular function was quantified, using a Argus function software of Siemens Healthineers. The location, pattern, and extent of DE were evaluated.

Results: Global left ventricular function and mass calculations yielded a mean ± SD for ejection fraction of 64.8 ± 11.7%, an end-diastolic volume of 111.5 ±27.2ml, and a left ventricular mass of 181.4 ± 96.2g. Diffuse hypertrophy was present in 12 patients (44.5%), asymmetric septal hypertrophy in 11 patients (40.7%), and apical hypertrophy in 4 patients (14.8%). LGE occurred in 24 patients (88.9%) and in 164 segments (33.7%), most commonly in the anteroseptal and inferoseptal segments. LGE was detected in an ill-defined patchy pattern in 61.6% and in a focal nodular pattern in 38.4% enhanced segments. LGE with an extent ≥ 50% was observed in 61 segments (37.2%), and that with an extent < 50% was observed in 103 segments (62.8%). There were significant difference in EF between the LGE-positive patients and the LGE-negative patients (p = 0.03). The myocardial wall was thicker in the enhanced segments than in the non-enhanced segments (p < 0.001). No significant difference was found in wall thicker of segments between ill-defined patchy pattern and focal nodular pattern in our study. The enhanced segments with the transmural extent ≥ 50% were thicker than non-enhanced segments and the enhanced segments with an extent < 50% were thicker than nonenhanced segments at end-diastole and at end-systole (p < 0.01).

Conclusion: Cardiac MR imaging is beneficial in making a diagnosis and determining the phenotype of HCM because it can observe the cardiac morphology clearly and evaluate its function comprehensively. It is possible to accurately measure the wall thickness, detect high-risk phenotypes and determine myocardial fibrosis based on late myocardial enhancement. Therefore, it is necessary to perform cardiac MR imaging in patients with HCM or suspected HCM on clinical examination.

Keywords: Hypertrophic cardiomyopathy, late gadolinium enhancement