Assessment of atrial diastolic function in patients with hypertrophic cardiomyopathy by cine magnetic resonance imaging

Purpose: This study was conducted to assess the role of atrial function by cardiac magnetic resonance (CMR) for the evaluation of diastolic physiology in patients with hypertrophic cardiomyopathy (HCM) compared to healthy controls. Materials and methods: We enrolled 23 consecutive patients affected by HCM and 43 healthy subjects as age-matched control cases (CC). CMR was performed through acquisition of cine steady-state free precession sequences using a 1.5-T scanner. Image postprocessing was carried out using Tracking Tool software. Results: Atrial volumes were significantly higher in patients with HCM compared to CC: maximum atrial volume (p = 0.007) and minimum atrial volume (p = 0.01). A statistically significant difference was also observed in atrial ejection fraction in patients with HCM (p < 0.0001). The atrial volume curves defined as cavity volume over time (dV/t) showed significant differences: early atrial peak emptying rate (PERE) (maximum rate of emptying independent of atrial contraction) in HCM was −146 ± 53 ml/s versus −227 ± 86 ml/s in CC (p < 0.0001); active atrial peak emptying rate (PERA) (maximum rate of emptying secondary to atrial contraction) in HCM was −256 ± 80 ml/s versus −216 ± 104 ml/s in CC (p = 0.05); the atrial PER E/A ratio in HCM was 0.6 ± 0.2 versus 1.05 ± 0.5 in CC (p < 0.0001). Conclusions: This study demonstrated that in HCM patients with early diastolic dysfunction the parameters of left atrial function assessed by CMR are impaired before the ventricular diastolic indexes such as the early peak filling rate and the active peak filling rate.