Assessment of left atrial function and diastolic dysfunction in patients with Becker muscular dystrophy

Abstract Background Becker muscular dystrophy (BMD) is frequently characterized by myocardial involvement1 but little is known about the prevalence of left ventricular (LV) diastolic dysfunction (DD) in these patients, particularly when using more recently proposed measure of left atrial (LA) function. Purpose Purpose of our study was to assess LVDD in patients with BMD using the currently recommended echocardiographic multiparametric approach and adding LA reservoir strain as advanced measure of LVDD. Methods A total of 33 BMD patients (38±13 years) were analyzed including standard and advanced echocardiography at the time of their first visit and at 24 months follow-up. A control group consisted of 20 age- and gender-matched healthy subjects. Results 18% of BMD patients showed an e'lateral <10, 0% an E/e' >14, 22% a LAVI >34ml/m2 and 11% a tricuspid velocity >2.8m/s. When applying the currently recommended multiparametric approach, 83% of BMD patients showed normal DD and 17% showed indeterminate LV diastolic dysfunction (50% positive parameters); no BMD patient had >50% positive DD parameters for confirmed DD. LA reservoir strain was significantly lower in BMD patients as compared to controls (28±10% vs. 42±11%; p<0.001) (Figure), while LA indexed volume (LAVI) was not (26±19 ml/m2 vs. 21±6 ml/m2; p=0.142). When using the reported median value of LA reservoir strain (47%) for normal subjects with comparable age2, 31 (94%) BMD patients had impaired LA strain, but when using the cut-off value of <19% for increased LV filling pressure, 6 (18%) patients showed affected LA reservoir strain. Patients with more impaired six minute walk test (6MWT), defined as in the 1st tertile (1st tertile 0–309m; 2nd tertile 310–523m; 3rd tertile >523m) had significantly lower LA reservoir strain (1st tertile, 22±6% vs. 2nd tertile, 29±14% vs. 3rd tertile, 33±5%; p=0.022). LA reservoir strain tended to deteriorate at 1 year follow-up but not significantly (from 29±10% to 26±12%; p=0.200). Conclusions LVDD is not highly prevalent in BMD patients but LA dysfunction as assessed by LA reservoir strain is reduced and may improve detection of myocardial involvement in these patients, also over time. Funding Acknowledgement Type of funding sources: None.