Left atrial mechanical functions in patients with anterior myocardial infarction: a velocity vector imaging-based study.

BACKGROUND The contribution of the left atrium (LA) to left ventricular (LV) function increases in myocardial infarction (MI). AIM To evaluate LA function by using volume measurements and a novel strain imaging method, namely velocity vector imaging (VVI), in patients with acute anterior MI. METHODS Twenty-four patients with previous anterior MI (aged 63.8 ± 4.2 years, 56% men) and 30 healthy controls (aged 60.7 ± 5.3 years, 60% men) were enrolled. LA volume measurements and VVI-derived LA peak systolic strain (S), strain rate (SRs), early diastolic (ESRd) and late diastolic strain rate (LSRd) were measured. LV diastolic function was analysed by pulsed wave-Doppler and tissue velocity ımaging. RESULTS LA maximum volume index was increased in patients compared to controls (28.83 ± 7.2 vs. 19.72 ± 6.27 mL/m²,p = 0.0001). As LA active emptying volume index and fraction were increased (6.16 ± 0.7 vs. 5.46 ± 0.99 mL/m², p = 0.009 and 22.16 ± 3.07 vs. 16.78 ± 2.93%, p = 0.0001, respectively), passive emptying volume index and fraction were decreased in the patient group (6.09 ± 0.57 vs. 7.57 ± 0.61 mL/m², p = 0.0001 and 45.76 ± 6.86 vs. 56.45 ± 5.36%, p = 0.0001, respectively). However, total emptying volume index of the LA was similar between the two groups. VVI-derived LA peak systolic S, SRs and ESRd were impaired in the patient group. LA LSRd was similar between the groups. LA active emptying fraction was positively correlated with LV diastolic dysfunction and negatively correlated with LV systolic dysfunction. CONCLUSIONS We demonstrated increased LA booster function and decreased LA conduit and reservoir functions in patients with prior anterior MI. Improvement in LA booster function correlated with the degree of LV systolic and diastolic dysfunction, suggesting a compensatory response of the LA.