Despite accumulating data regarding the safety of dobutamine stress testing, the possible induction of tachyarrhythmias during the test remains a major concern for physicians, particularly in patients with extensive coronary artery disease (CAD) or left ventricular dysfunction. The aim of this study is to evaluate the clinical, echocardiographic, and angiographic predictors of arrhythmias during dobutamine stress testing. Dobutamine (up to 40 microg/kg/min)-atropine (up to 1 mg) stress echocardiography was performed in 286 patients (age 58 +/- 11 years, 200 men) with suspected myocardial ischemia who underwent coronary angiography within 3 months of the test. Wall motion score index was derived using a 16 segment/4 grade score model where 1 = normal and 4 = dyskinesia. No myocardial infarction or death occurred during the test. Ventricular and supraventricular tachycardia occurred in 16 (6%) and 21 (7%) patients, respectively. Systolic blood pressure decrease > or = 40 mm Hg occurred in 7 patients (2%). Significant CAD was detected in 220 patients (77%). There was no significant difference between patients with and without tachyarrhythmias with regard to the prevalence of CAD (78% vs 77%) or the mean number of diseased coronary arteries (1.51 +/- 0.7 vs 1.45 +/- 0.8). Independent predictors of tachyarrhythmias by multivariate analysis of clinical, angiographic, and echocardiographic characteristics were a higher resting wall motion score index (p <0.01) and mole gender (p <0.05). Independent predictors of systolic blood pressure decrease > or = 40 mm Hg were a higher baseline systolic blood pressure (p <0.0001), a history of myocardial infarction (p <0.0001), and a higher resting wall motion score index (p <0.01). It is concluded that tachyarrhythmias during dobutamine stress testing are predicted by the extent of left ventricular dysfunction but not by the presence or the extent of CAD.