الفهرس 
Dobutamine EchocardiographyOnly 14 pages are availabe for public view
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Abstract
While the use of beta blockers is widespread due to its antihypertensive as well as cardioprotective effects, the negative effects on heart rate and inotropy lead to high incidence of nondiagnostic test results when patients undergo stress testing on beta blockers.
The aim of this study is to evaluate the role of DSE versus ETT in achieving THR among patients on concurrent beta blockers
Our study included 50 patients. The patients were divided into two groups, group A included 25 patients, who underwent exercise stress ECG using treadmill. Group B included 25 patients, who underwent pharmacologic stress echocardiography using dobutamine.
All patients continued their beta blocker regimen and underwent their stress testing either by exercise test using treadmill or pharmacological dobutamine testing while they were on beta blocker therapy.
Patients of Group A were evaluated initially with resting ECG and stressed using the standard Bruce protocol.
Dobutamine stress echocardiography was done to patients of Group B. A graded dobutamine infusion was started at a dose of 5ug/kg/min then the dose was increased to 10,20,30 up to 40 ug/kg/min in 3 min stages increment. In patients who did not achieve 85% of predicted maximum heart rate (PMHR) (220-age) with the maximum dose of dobutamine, atropine was administered in doses of (0.6-1mg) each minute, up to a maximum of 2.0 mg.
Images were acquired at rest, low dose, peak stress and recovery phases and displayed side by side in a quad screen format and were analyzed.
The results of our study in each group were compared to each other and with pervious studies reported before addressing the same issue.
In our study, the mean age of Group A was (51.48±9.85) vs (56.12±8.90) for Group B; there was no significant difference as regards age of patients. Both groups were sex matched.
In our study, no significant difference as regards resting heart rate. Peak heart rate of Group B was significantly higher than Group A. No significant difference between Group A and Group B as regards blood pressure whether resting or peak reading.
The test duration in our study was significantly shorter during ETT than during DSE (9.1±1.91 min for ETT vs 14.12±2.37 min for DSE protocol).
In our study, 24 patients (96%) achieved THR among patients of DSE group vs 16 patients (64%) of ETT group.
Finally, we concluded that DSE is superior to exercise stress testing in achieving THR among patients on β-blockers.