RESUMO
BACKGROUND: Increased left atrial (LA) size has been proposed as a predictor of multiple adverse cardiovascular events including stroke. LA dysfunction can occur in the absence of increased LA size. However, the relationship between stroke and changes in LA function is not well known. METHODS: Patients with acute ischemic stroke and healthy controls were enrolled prospectively. Stroke patients received standard work-ups to determine the etiology of their strokes. Those patients with significant cardiac arrhythmia and heart failure were excluded. All participants received echocardiography examination. Conventional echocardiographic parameters were calculated and cardiac contractile characteristics of the left atrium and left ventricle were analyzed using vector velocity imaging (VVI) technique. RESULTS: In total, 87 patients with acute ischemic stroke and 20 controls were recruited. The mitral inflow E-wave velocities were lower and A-wave velocities were higher in stroke patients (0.76 ± 0.19 vs. 0.84 ± 0.16, p = 0.048; and 0.97 ± 0.20 vs. 0.76 ± 0.11, p < 0.001 respectively). Stroke patients had a higher active emptying percent of total LA emptying (60.5 ± 19.0%) compared with that in controls (33.5 ± 11.7%, p < 0.001). The minimal LA volume was larger in stroke patients (15.0 ± 10.5 mL) than that in controls (9.9 ± 4.2 mL, p = 0.021), whereas there was no difference in maximal LA volume between stroke patients (37.3 ± 16.5 mL) and controls (33.3 ± 9.9 ml, p = 0.366). The diastolic emptying index of the LA was significantly lower in stroke patients compared with that in controls (61.4 ± 14.6% vs. 70.2 ± 11.0%, p = 0.016). The mitral A-wave velocity and active emptying percent of total LA emptying were significantly higher in all stroke subtypes than those in controls. CONCLUSION: Acute ischemic stroke patients had altered mitral inflow velocities and emptying function of the left atrium. VVI is convenient for quantitative assessment of left atrial volumes and contractile characteristics. Functional changes of LA may occur without significant structural changes. Therefore, the clinical implications of LA functional indexes require further study.
