Parameters of left atrial during stress in patients with asymptomatic primary mitral regurgitation

Abstract

Abstract Introduction Progressive volume overload caused by chronic mitral regurgitation (MR) leads to left atrium (LA) and left ventricle (LV) remodeling. Despite these structural changes, most of MR patients may remain asymptomatic for a long time. LA enlargement and reduced LA deformation parameters in asymptomatic MR patients predict a worse prognosis and may provide additional information to guide for earlier surgery. Purpose The aim of the study was to evaluate changes of LA size and deformation parameters in patients with asymptomatic primary MR during stress. Methods 84 asymptomatic patients (age 59.87±13.47 years) with sinus rhythm and preserved left ventricle (LV) ejection fraction (EF) (>50%) at rest were included in the study. Resting and stress (veloergometry as per protocol 25 + 25 W every 3 minutes) echocardiography and speckle tracking off-line analyses were performed to 52 (61.9%) patients with moderate MR (MR group) and 32 (38.1%) patients without significant heart valves disease (control group). Statistical analyses were performed using the SPSS 20.0 software. The value of p<0.05 was considered as statistically significant. Results Volume index of LA was significantly higher in subjects with MR (picture 1). LA area was similar in MR and control groups at rest. However, during stress LA area became significantly larger in MR group (picture 1). LA myocardial deformation parameters were calculated during 3 phases of LA cycle: reservoir phase strain (LASr), conduit phase strain (LAScd), contraction phase strain (LASct). At rest, during peak stress and at recovery phase all of them were higher in controls but difference was not significant. During initial stress (25 W) LAScd was significantly higher in MR group (−16.86±−8.06% vs. −11.33 ±−6.26% p=0.034), while healthy subjects had a tendency to lower LASr (20.32±10.53% vs. 22.7±10.89%, p=0.535) (picture 1). Better LV EF at rest was related to smaller LA area (p=0.003, r – 0.390) and volume index (p=0.020, r – 0.308) during peak stress. Conclusions Stress provokes significant increase of LA size (volume and area) and LAScd in patients with primary mitral regurgitation. Other myocardial deformation parameters of LA were not significantly related to MR. LV EF at rest correlates with LA parameters during peak stress. Changes of LA parameters during stress Funding Acknowledgement Type of funding source: None