['To evaluate the angiographic, myocardial perfusion, and wall motion abnormalities in patients with severe compared with mild worsening of regional function during dobutamine stress echocardiography (DSE) for evaluation of myocardial ischaemia.', '147 patients with significant coronary artery disease and new or worsening wall motion abnormalities during DSE were enrolled. Left ventricular function was evaluated using a 16 segment/4 grade score model where 1 = normal and 4 = dyskinesis. Simultaneous sestamibi SPECT myocardial perfusion imaging was performed in all patients.', 'Severe worsening of regional function (an increase in wall motion score of two grades or more in >/= 1 segment) was detected in 37 patients, while 110 patients had mild worsening (an increase in wall motion score of no more than one grade in >/= 1 segment). Patients with severe worsening of regional function had more stenotic coronary arteries (2.31 (0.8) v 1.97 (0. 8) (mean (SD)) (p <0.05), a higher prevalence of left anterior descending coronary artery disease (95% v 73%) (p < 0.05), a higher resting wall motion score index (1.71 (0.42) v 1.51 (0.40) (p = 0. 01), and more stress perfusion defects (3.8 (1.5) v 2.8 (1.5) (p < 0.001) compared with patients with mild worsening. Multivariate analysis identified the number of stress perfusion defects (p < 0. 005, chi(2) = 8.8) and the number of ischaemic segments on echocardiography (p < 0.05, chi(2) = 4.3) as independent variables associated with severe worsening of regional function.'] Does the grade of worsening of regional function during dobutamine stress echocardiography predict the extent of myocardial perfusion abnormalities?