RESUMO
The purpose of this study was to establish the safety of high-dose dobutamine-atropine stress echocardiography in patients with suspected or proven coronary artery disease. Six hundred fifty consecutive examinations were completed. Mean age of patients was 61 years; 300 had a previous myocardial infarction. Heart rate increased from 73 to 129 beats/min during stress testing, blood pressure did not change significantly (from 140/81 to 150/80 mm Hg). Atropine was added to dobutamine in 239 patients when no ischemia was induced with dobutamine alone and the peak heart rate was < 85% of the theoretical maximal heart rate. Atropine was more frequently administered to patients taking beta blockers (77 vs 27%, p < 0.001). New wall motion abnormalities developed in 243 patients (37%). Significant or symptomatic cardiac tachyarrhythmias, or both, developed during 24 examinations: 1 patient developed ventricular fibrillation, 3 patients developed sustained ventricular tachycardia, 12 patients experienced nonsustained ventricular tachycardia (< 10 beats) and 8 patients had paroxysmal atrial fibrillation. Cardiac arrhythmias were more frequent in patients with a history of ventricular arrhythmias (ventricular tachycardia and fibrillation) (odds ratio 9.9, 2.0 to 45) or left ventricular dysfunction at rest (wall motion score > 1.12) (odds ratio 2.9, 1.1-7.6), but not associated with atropine addition. No death or myocardial infarction occurred. The full dose was not given to 13 patients despite absence of signs or markers of ischemia for limiting side effect, yielding an overall feasibility of the stress test of 98%.(ABSTRACT TRUNCATED AT 250 WORDS)
