[The side effects and safety of the echo-dobutamine test. The experience with 373 patients].

BACKGROUND

A potential limitation to the clinical utilization of dobutamine stress echocardiography is the higher incidence of side effects in respect to other noninvasive tests for the diagnosis of coronary artery disease reported by some authors. Due to the increased utilization of this test for the evaluation of chest pain and for prognostic stratification in patients with a recent myocardial infarction, we analyzed the results of 373 consecutive tests to evaluate the incidence and clinical significance of side effects induced by dobutamine.

METHODS

Dobutamine stress echocardiography was performed in 256 patients (69%) for the evaluation of chest pain; 85 out of 256 (33%) suffered from a previous myocardial infarction. 117 patients (31%) were studied in the early phase after an acute myocardial infarction for prognostic purposes. Dobutamine was infused starting with the dose of 5 gamma/kg/min over 3 minutes with incremental steps of 10-20-30-40 gamma/kg/min over 3 minutes under 2D-echocardiographic and 12-lead electrocardiographic monitoring.

RESULTS

In 95% of cases the test was stopped at the achievement of a target end point: wall motion abnormalities (60%), significant ECG changes (5%), 85% of the age-predicted maximal heart rate (13%), maximal dose (17%); only in 5% of cases a limiting side effect requiring a premature interruption of the test occurred: hypertension (systolic blood pressure over 240 mm Hg and/or diastolic over 120 mm Hg) (2%); symptomatic hypotension (0.5%); severe chest pain (1%); nausea (0.5%); cardiac arrhythmias (1%). Cardiac arrhythmias were the most frequently registered non limiting side effect. During the test 79 episodes of supraventricular arrhythmias and 211 episodes of ventricular arrhythmias occurred. Supraventricular arrhythmias consisted usually of benign sporadic premature beats; only 3 cases of self-limiting supraventricular tachycardia or atrial fibrillation were recorded. Sporadic ventricular premature beats were the most frequently recorded arrhythmias; 10 patients developed a ventricular tachycardia; however in no case this arrhythmia was sustained, associated with subjective symptoms and required the administration of a specific antiarrhythmic drug or the premature interruption of the test. Patients were divided according to the absence (Group 1, G1, n = 193, 52%) or the presence (Group 2, G2, n = 180, 48%) of cardiac arrhythmias during the test. Patients of G2 differed from patients of G1 only in respect of the maximal dose of dobutamine infused (33.5 vs 28.6 gamma/kg/min, p < 0.0005) and the incidence of a wall motion abnormality in the basal echocardiogram (66% vs 53%, p < .01). The second most recorded non limiting side effect (71/373 pts) (19%) was the occurrence of systolic hypotension, a drop of systolic blood pressure > or = 20 mm Hg in respect of the antecedent infusion step. In all cases no symptoms developed and the great majority of patients with this finding had a normal echocardiographic response to dobutamine at the time of his occurrence.

CONCLUSIONS

Dobutamine echo stress test is limited by the occurrence of significant side effects only in a minority of patients (5%); however in all cases, including complex ventricular arrhythmias, these side effects were self limiting and promptly recovered after interruption of the drug infusion. Non limiting side effects, in particular cardiac arrhythmias and systolic hypotension, are usually well tolerated and not associated with the occurrence of myocardial ischemia or left ventricular disfunction; thus, dobutamine echo stress test may be considered a safe test for the evaluation of the presence and severity of coronary artery disease both in patients with a previous or recent myocardial infarction and in patients without myocardial infarction.