title: Comparison between accelerated and conventional dobutamine stress protocols for myocardial perfusion scintigraphy.
abstract: The conventional dobutamine (Dob) stress protocol for myocardial perfusion scintigraphy (MPS) is long, with frequent adverse effects, and generally requires atropine injection to reach target heart rate. Atropine is usually administered at the end of the protocol, when adverse effects are more frequent. Earlier atropine injection may be useful to shorten the stress protocol and reduce adverse effects. We sought to compare a Dob stress protocol with early atropine injection to a conventional Dob stress protocol in the same patients undergoing MPS. 30 patients underwent Dob-MPS with a conventional protocol (steps of 10, 20, 30 and 40 mcg/kg/min at 3 min intervals, adding atropine to the maximal Dob dose if necessary to achieve 85% of the age-corrected maximal predicted heart rate) and with an accelerated protocol with early atropine injection (at the end of the first stage). We compared stress duration, maximal heart rate (HR), percentage of maximal predicted HR, rate-pressure product, ST changes, MPS scores and the incidence of adverse effects between the 2 protocols. The accelerated protocol was shorter than the conventional protocol (7.1 ± 3.4 min vs. 11.8 ± 1.3 min; P < 0.0001), had the same efficacy to achieve hemodynamic parameters, without increasing adverse effects. The summed stress scores obtained by automatic analysis were similar in both protocols (6.3 ± 6.3 vs. 6.8 ± 6.3; P = NS) as well as the summed difference scores (2.5 ± 3.6 vs. 2.7 ± 3.4; P = NS). Early atropine injection during dobutamine stress protocol shortens stress duration. Our results suggest that patient safety and accuracy of MPS are unaltered, when compared to the conventional protocol, but further, larger studies are still necessary.
authors.affiliation: Cardiology Division, Department of Internal Medicine, Federal University of Rio de Janeiro, Rua Rui Vaz Pinto, 220/301 Rio de Janeiro, RJ 21931390, Brazil.
authors.forename: Aurora
authors.initials: A
authors.lastname: Issa
authors.forename: Andrea
authors.initials: A
authors.lastname: De Lorenzo
authors.forename: Bernardo
authors.initials: B
authors.lastname: Oliveira
authors.forename: Marcos
authors.initials: M
authors.lastname: Pellini
authors.forename: Ronaldo
authors.initials: R
authors.lastname: Lima
mesh_terms: D058665:Adrenergic beta-1 Receptor Agonists; D000368:Aged; D001285:Atropine; D001794:Blood Pressure; D016009:Chi-Square Distribution; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004280:Dobutamine; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D018727:Muscarinic Antagonists; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D058665:Adrenergic beta-1 Receptor Agonists; D018727:Muscarinic Antagonists; D004280:Dobutamine; D001285:Atropine