Correlation between left ventricular myocardial fibrosis and left atrial dysfunction in patients with non-obstructive hypertrophic cardiomyopathy.

This study aimed to investigate the impact of left ventricular myocardial fibrosis on left atrial function in patients with non-obstructive hypertrophic cardiomyopathy (NOHCM). A total of 103 NOHCM patients and 28 healthy controls (HC) were included retrospectively. Patients were stratified based on late gadolinium enhancement (LGE) into the following groups: NOHCM LGE (-) group, mild LGE% (+) group (LGE% < 7%), moderate LGE% (+) group (7% ≤ LGE% < 15%), and severe LGE% (+) group (LGE% ≥ 15%). CMR-FT strain analysis assessed left atrial strain and strain rate across different cardiac phases. Statistical analyses for clinical and imaging parameters, and Spearman correlation analysis for assessing correlations between left ventricular myocardial fibrosis and left atrial volume and function. There were no significant differences in left atrial function and volume parameters between the LGE (-) group and the mild LGE% (+) group. However, εs, εe, SRs, and SRe showed gradual decreases across mild, moderate, and severe LGE% (+) groups, with significant differences observed among the three groups. εa and SRa in the moderate and severe LGE% (+) groups were significantly lower than those in the mild LGE% (+) group. There are strong correlations between the degree of left ventricular myocardial fibrosis and LAEF, LAEDV, LAESV, εs, εe, εa, SRs, SRe, and SRa. As left ventricular myocardial fibrosis progressed, left atrial function deteriorated further, highlighting an interaction between left ventricular myocardial structure and left atrial function that promotes NOHCM progression. Complement the guidelines（2020 AHA/ACC Guideline for the Diagnosis and Treatment of Patients With Hypertrophic Cardiomyopathy）.