Left atrial minimum volume by real-time three-dimensional echocardiography as an indicator of diastolic dysfunction.

Background: Left atrial (LA) maximum volume is becoming a prognostic biomarker for left ventricular (LV) diastolic dysfunction. However, we assessed LV diastolic function by measuring LA phasic volumes using real-time threedimensional echocardiography (RT3DE) in patients with stable coronary artery disease (CAD).

Methods: Sixty-five stable CAD patients with normal LV ejection fraction (LVEF) were divided into three groups according to degree of coronary stenosis: control (n = 15) with <50% stenosis as control group, mildS (n = 25) with mild stenosis (50%-70%) and severeS (n = 25) with >70% stenosis. LA phasic volumes and function were evaluated and compared using RT3DE and two dimensional echocardiography (2DE). N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were examined. The correlations of RT3DE-derived parameters with other conventional indices were analyzed.

Results: Significant correlations between RT3DE and 2DE for LA volume measurements were: control, r = 0.93; mildS, r = 0.94; severeS, r = 0.90 (all P < 0.05). Patients with severe coronary stenosis presented higher NT-proBNP level, indices of LA minimum volume and volume before atrial contraction, but lower LA total emptying fraction (LAEF) and LAEFpassive. Significant correlations of RT3DE derived LA volume indices with E/E' (r = 0.695) and NF-proBNP (r = 0.630) level were found.

Conclusions: RT3DE derived, LA indices correlate well with NT-proBNP level and may be superior to 2DE measurements for the evaluation of LV diastolic dysfunction. Enlargement of LA minimum volume in stable CAD patients without systolic dysfunction appears earlier and may be better correlated with LV diastolic function than that of LA maximum volume.