Feasibility Study On Real-time Triplane Strain Rate Imaging For Quantitative Assessment Of Left Atrial Function

Objective To evaluate the feasibility and clinical value of real-time triplane strain rate imaging for the quantitative assessment of left atrial function. Methods Totally 40 normal subjects and 30 patients with hypertrophic cardiomyopathy (HCM) were enrolled. Pre-atrial contraction left atrial volume, minimal left atrial volume and maximal left atrial volume were measured using real-time triplane volume imaging. Left atrial expansion index (LAEI), left atrial passive emptying fraction (LAPEF) and left atrial active emptying fraction (LAAEF) were calculated. Systolic peak strain rate, early diastolic peak strain rate and late diastolic peak strain rate were measured using real-time triplane strain rate imaging in left atrial lateral, septum, anterior, inferior and posterior walls. Mean systolic peak strain rate (MSRs), mean early diastolic peak strain rate (MSRe) and mean late diastolic peak strain rate (MSRa) were calculated. The results were compared. Results In normal subjects, MSRs correlated positively with LAEI (r=0.61, P<0.01), MSRe correlated inversely with LAPEF (r=-0.67, P<0.01), So did MSRa with LAAEF (r=-0.78, P<0.01). In patients with HCM, MSRs correlated positively with LAEI (r=0.62, P<0.01), MSRe correlated inversely with LAPEF (r=-0.68, P<0.01, So did MSRa with LAAEF (r=-0.74, P<0.01). The interventricular septum thicker in HCM patients than in normal subjects group(P<0.05), MSRs, MSRe and MSRa were significantly different between normal subjects and patients with HCM (P<0.05). Conclusion Real-time triplane strain rate imaging is feasible for the quantification of left atrial regional myocardial function. Left atrial local dysfunction is able to be detected by real-time triplane strain rate imaging in patients with HCM.