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Clin. Cardiol. 24, 141–145 (2001)
David Lu, M.D., Michael D. Greenberg, M.D.,* Raymond Little, M.D., Qudsia Malik, M.D., Daniel J. Fernicola, M.D., Neil J. Weissman, M.D.†
Washington V.A. Medical Center, *Martinsburg Veterans Affairs Medical Center, and †The Cardiovascular Research Institute, Washington Hospital Center, Washington, D.C., USA
Summary
Background: Dobutamine pharmodynamics require approximately 10 min to reach steady state. Despite this, standard dobutamine stress echo typically uses 3-min stages of advancing dobutamine doses because of safety concerns.
Hypothesis: In patients with a high pretest probability of coronary artery disease (CAD), a continuous infusion of high-dose dobutamine is a feasible and safe method for performing a dobutamine stress test.
Methods: Forty-seven consecutive patients (mean age 64 ± 11 years) with 3.0 ± 1.4 cardiac risk factors underwent dobutamine stress testing utilizing a single, high-dose (40 mcg/kg/min), continuous dobutamine infusion. The 40 mcg/kg/min infusion was continued for up to 10 min or until a test endpoint had been reached. If a test endpoint was not achieved, atropine (up to 1.0 mg) was added.
Results: Heart rate rose from 71 ± 12 to 137 ± 18 beats/min at peak (p<0.0001) with a concomitant change in systolic blood pressure (143 ± 35 vs. 167 ± 38 mmHg; p = 0.001) but no change in diastolic blood pressure (74 ± 19 vs. 75 ± 18 mmHg; p = NS). Target heart rate was achieved in 20 of 47 (43%) patients with accelerated dobutamine alone and in 34 of 47 (72%) with the addition of atropine. An average of 11.6 ± 3.7 min was required to obtain target heart rate. Subjective sensations from the dobutamine occurred in 49% of patients (palpitations 21%, nausea 6%, chest pain 6%, headache 6%, dizziness 13%), mild arrhythmia in 48% of patients (ventricular premature beats 38%, supraventricular tachycardia 10%), and one patient had nonsustained ventricular tachycardia.
Conclusion: A single, high-dose (40 mcg/kg/min) dobutamine-atropine protocol provides an efficient means of performing dobutamine stress echocardiography with a similar symptom profile as conventional dobutamine infusion protocols in patients with a high pretest probability of CAD. Randomized, controlled studies will be necessary to assess the sensitivity and specificity of this accelerated dobutamine echo protocol.
Key words: pharmacologic stress testing, atherosclerosis, echocardiography, dobutamine, stress echocardiography
Address for reprints:
Neil J. Weissman, M.D.
Cardiovascular Research Institute
Washington Hospital Center
110 Irving Street, NW, Suite 4B-1
Washington, DC 20010, USA
Received: December 22, 1999
Accepted with revision: March 29, 2000