Left atrial size during dobutamine stress echocardiography

Left atrial (LA) size may be an expression of left sided hemodynamics. The changes in LA size during Dobutamine Stress Echocardiography (DSE) have not been reported. We measured left atrial area (LAA) in apical 4-chamber view at rest and at peak DSE in 3 groups of patients (pts); Group I, 29 pts with normal LV at rest and at peak DSE; Group II, 21 pts with positive DSE, 17 of 21 pts had abnormal resting LV function; Group III, 18 pts with abnormal LV function, mild to moderate mitral regurgitation (MR) at rest and positive DSE, Age and sex of pts in 3 groups were similar. Group I had higher peak DSE heart rate (bpm) 132 compared to 117 in Group II and 118 in Group III (p<0.001). Mean ± SD LV ejection fraction (LVEF) and LAA were: LVEF(%) LAA(cm²) Group Rest DSE Rest DSE P I 58.6±3.8 * 72.3±4.8 * 9.2±1.6 8.1±1.4 <0.01 II 51.4±10 62.6±10 9.3±1.4 8.6±1.9 NS III 46.7±9.2 59.4±10 12.4±2.0 ** 9.8+2.0 <0.001 * P <0.001 compared to II/III ** p<0.001 compared to I/II LAA decreased from rest to peak DSE in all Group I pts and in 17 of 21 Group III pts. In group II, LAA decreased slightly or remained unchanged in 12 pts and increased in 9 pts. The reductions in peak DSE LAA in group I and II were significant when compared to Group II (P<0.05). The lack of change in left atrial size, in pts without mitral regurgitation, abnormal left ventricular function and positive DSE, may be reflection of adverse hemodynamics.