Characterization of left atrial geometry and function in patients with hypertrophic cardiomyopathy: a cardiac magnetic resonance imaging study.

OBJECTIVE: Left atrial (LA) remodelling is an interesting pathological aspect in hypertrophic cardiomyopathy (HCM) which has not been yet fully understood. Also, a comprehensive evaluation of LA alterations in HCM is still lacking. Cardiac magnetic resonance imaging (cMRI) can precisely characterize LA function and structure. We sought to thoroughly assess LA remodelling using cMRI in patients with HCM. PATIENTS AND METHODS: We enrolled 105 patients with HCM and 105 healthy controls. LA parameters determined by cMRI comprise LA volume (LAV), total ejection fraction (LATF), total strain LA- εt, passive ejection fraction (LAPF), passive strain LA-εe, active ejection fraction (LAAF), active strain LA-εa. LA sphericity index (LASI) and LA strain were also determined. Parameters of LV systolic and diastolic functions were also assessed. RESULTS: LAV and LASI were significantly increased, while LA phasic functions were decreased in patients with HCM (p<.001). LATF was inversely correlated with LV long-axis strain (r= -0.466, p<.0001) and mass (r= -0.515, p<.0001), and as well with filling pressures, described by E/E' (r= -0.424, p<.0001). LA volumes, phasic functions and geometry were negatively associated with LV measurements, whereas a positive correlation between the LATF and LA strain (r = 0.496, p<.0001) was found. In addition, LAV was closely related to diastolic dysfunction severity (p<.0001). CONCLUSIONS: In patients with HCM, all three LA phasic functions were impaired, being directly related to LA enlargement. LASI and LA strain predicted LA reservoir function impairment.