Safety of dobutamine stress echocardiography : A 24 h Holter monitoring study

Dobutamine-atropine stress echocardiography is an efficient method in the evaluation of patients with coronary artery disease. However, because high-dose dobutamine is potentially arrhythmogenic, the safety of this stress modality has been questioned. We performed a 24 h Holter monitoring, before and immediately after this test, in 73 consecutive patients (60 men and 13 women), mean age 60 +/- 12 years. Twenty-eight patients had had a recent myocardial infarction, 25 had stable chronic angina, 10 chronic ischaemic cardiomyopathy and 10 idiopathic dilated cardiomyopathy. Dobutamine was progressively increased (5-40 micrograms.kg-1.min-1) and atropine was injected in 30 patients. Arrhythmias and ST-segment deviation before and after the stress test were evaluated. The mean peak dobutamine dose was 32 +/- 11 micrograms.kg-1.min-1. The heart rate at rest and at peak dose was, respectively, 69 +/- 16 and 110 +/- 28 beats.min-1. Side effects during the injection of dobutamine were mainly ventricular (n = 14) or atrial (n = 4) premature contractions. Three patients had non-sustained ventricular tachycardia and five had hypotension during the test. No sustained episode of supraventricular or ventricular tachycardia was observed during the study. Non-sustained supraventricular and ventricular tachycardias were detected in 8 and 21 patients before and in 11 and 16 patients after dobutamine stress echocardiography (P = ns). Asymptomatic ST-segment deviation was observed in two patients before and four after dobutamine stress echocardiography. An increase in total ischaemic time (20 vs 102 mn) was observed after the test, but only five patients had ST modifications. A separate analysis of patients with and without beta-blocker did not alter these results. In addition, when the occurrence of significant arrhythmias was stratified according to a left ventricular ejection fraction threshold of 45%, we observed no difference in frequency and severity of cardiac arrhythmias. This study demonstrates that dobutamine stress echocardiography does not significantly increase arrhythmia during the following 24 h. Further studies are required to evaluate the influence of the test on ST-segment modification during the same period.