Chrome congestive heart failure

Dobutamine-atropine stress echocardiography is used for the non-invasive diagnosis of coronary artery disease, but stress test results may be influenced by beta-blockers. The aim of this study was to assess if the addition of atropine can compensate for the presence of beta-blockers in dobutamine stress echocardiography. Twenty-six patients referred for evaluation of chest pain were studied twice, on and off metoprolol 100 mg b.i.d (in random order sequence) with a wash-out period of at least 48 h. Dobuta,nine stress echocardiography was performed using up to 40 μg. kg−1 min−1, followed, if necessary, by the addition of atropine to achieve 85% of the age-predicted maximal heart rate, unless symptoms or markers of ischaemia appeared. Atropine was given to patients on beta-blockers more often [ (22126)vs(6126) ] than to those off beta-blockers (P<0·001). Heart rate at every stage of the test was lower on beta-blockers. Chest pain occurred in patients on beta-blockers significantly less than in those off beta-blockers (8% vs 46%), and the addition of atropine made no significant difference (31% vs 46%). During dobuta stress, new wall motion abnormalities occurred in three patients on beta-blockers (12%); this number increased to 15 after the addition of atropine (57%). New or worsened wall motion abnormalities occurred in 12 patients (46%) off beta-blockers with dobutamine alone and in 14 patients after adding atropine (53%). We conclude that (1) beta-blockers decrease the chronotropic effect and reduce the incidence of myocardial ischaemia during dobutamine stress, (2) the addition of atropine to dobutamine increases heart rate and equalizes the detection of ischaemia in patients on and off beta-blockers.