Impact of Beta Blockers on Dobutamine-Atropine Stress Echocardiography

Safety and Predictors of Complications with a New Accelerated Dobutamine Stress Echocardiography Protocol

BACKGROUND

This study sought to document the safety of a new accelerated dobutamine-atropine stress echocardiography protocol and to analyze its complications.

METHODS

Dobutamine-atropine stress echocardiography studies were performed using an incremental dobutamine infusion protocol from 20 to 40 microg/kg/min in 3-minute stages and followed by atropine.

RESULTS

A total of 962 patients were included. Mean age was 64 +/- 11 years and 584 were male (61%). Mean ejection fraction was 62 +/- 10%. Complications included hypertensive responses in 66 patients (7%), arrhythmias in 26 (2.7%), and symptomatic hypotension in 16 (1.7%). No patient developed heart failure, acute myocardial infarction, ventricular fibrillation, or died. The independent predictors of hypertensive responses were age, baseline systolic blood pressure, and treatment with nitrates. The independent predictors of arrhythmias were history of hypertension, previous coronary artery disease, and baseline heart rate.

CONCLUSIONS

This accelerated dobutamine-atropine stress echocardiography protocol is safe in a low-risk population and has a rate of complications similar to that reported for the standard protocol.

[Elective noninvasive test in the diagnosis of coronary disease in the aged]

BACKGROUND AND PURPOSE

The purpose of this study was to determine the best noninvasive test to diagnose coronary artery disease in the elderly. PATTERNS AND METHODS: We conducted a study on 56 elderly patients (> 65 years) with chest pain and no previous history of coronary artery disease. They underwent exercise stress test, dipyridamole echocardiography (0.84 mg/kg), dobutamine echocardiography (up to a total dose of 40 microgram/kg/min and atropine when it was necessary), dobutamine MIBI-SPECT and coronary angiography.

RESULTS

Angiography detected significant coronary artery disease in 41 patients. All tests used in this study had a similar sensitivity (conclusive exercise stress test 87%, dipyridamole echocardiography 83%, dobutamine echocardiography 80% and MIBI-SPECT 87%; p = NS). Coronary angiography did not identify significant lesions in 15 patients. Specificity of conclusive exercise stress test, dipyridamole and dobutamine echocardiography was similar (75%, 100% and 93% respectively; p = NS). However, the specificity of stress echocardiography was higher than that of scintigraphy (100% vs 66%; p = 0.02 for dipyridamole echocardiography and 93% vs 66%; p = 0.07 for dobutamine echocardiography). Diagnostic accuracy of each test was similar.

CONCLUSIONS

Exercise stress test remains the non invasive diagnostic test of choice to detect coronary disease in the elderly. If this test is inconclusive, both stress echocardiography and isotopic studies are useful, although the specificity of stress echocardiography is higher than that of scintigraphy.