Early atropine is safer than conventional atropine administration in the elderly undergoing dobutamine stress...

Early injection of atropine during dobutamine stress echocardiography has been demonstrated in retrospective analyses to reduce the duration and dose of dobutamine infusion, while preserving a similar diagnostic accuracy with a lower incidence of adverse effects.

In our prospective study, we sought to explore the safety of the early atropine-dobutamine stress echocardiography protocol compared to the conventional protocol in elderly patients.

We enrolled 100 consecutive elderly patients who had been referred to our echocardiography laboratory for evaluation of myocardial ischemia. Once eligible, patients were randomly assigned to undergo either the conventional protocol (Group 1, 50 patients) or early atropine protocol (Group 2, 50 patients) where atropine was started at dobutamine infusion rate of 20 microg/kg/min if the heart rate was < 100 beats/min, and at 30 microg/kg/min if the heart rate was < 120 beats/min, (max 2.0 mg). Test duration and total dobutamine dose were calculated.

The mean age of the whole study cohort was 69.8 +/- 2.8 years, 54 (54%) being males. Patients in Group 1 received a higher total dose of dobutamine (15.7 +/- 0.8 vs 12.2 +/- 1.5 mg) and had a longer test duration (14.3 +/- 3.5 vs 11.5 +/- 1.3 min) as compared to Group 2 (p < 0.01 for both). The two groups received a similar total dose of atropine (NS). Group 1 patients had a higher incidence of ventricular extra-systoles, non-sustained ventricular tachycardia, atrial fibrillation, and hypotension.

In elderly patients undergoing dobutamine stress echocardiography, adopting the early atropine protocol offers a shorter test duration and a lower dobutamine dose, with consequently fewer adverse effects.