Abstract 2089: Changes of Diastolic Doppler Indices During Stress Test: Head-to-Head Comparison of Dobutamine Versus Exercise Echocardiography
Background Exercise (EX) and dobutamine stress echocardiogeaphy (DSE) has not been standardized for evaluation of diastolic function.
Methods We performed EX and DSE (up to 30 μg/kg/min) in random sequences in 50 normal controls (31 men; age, 30 ± 5 years). Graded bicycle exercise was performed starting at an initial workload of 25 W and lasting for 3 minutes; thereafter, the workload was increased stepwise by 25 W at 3-minute intervals. The starting dobutamine dose was 5 μg/kg/min, which was increased to 10, 20, and 30 μg/kg/min. At each stage of both tests, comprehensive echocardiographic measurement of left ventricular (LV) volume, systolic (S′y (E′) and late (A′) diastolic annular velocity as well as transmitral inflow velocities (E and A) was done.
Results Similar heart rate-pressure product was achieved at workload of 75 W in EX and dobutamine dose of 30 μg/kg/min infusion in DSE. Increase of heart rate (82±29 vs 46±26%, p<0.001) was more prominent in EX, and systolic blood pressure increase (33±14 vs 51±20%, p<0.001) in DSE; although LV ejection fraction increased in both tests, progressive decrease of LV volume was characteristic in EX, whereas LV diastolic volume increased in DSE. All Doppler indices including E, S′, and E′ showed gradual increase during testing. Despite similar peak double product, increase of S′ (57±21 vs 92±30%, p<0.001) was significantly greater in DSE, whereas increase of E (79±31 vs 42±24%, p<0.001) and E′ (59±28 vs 19±18%, p<0.001) in EX. E/E′ did not change significantly in both tests.
Conclusion Diastolic Doppler indices showed more prominent changes during exercise testing than during dobutamine infusion despite similar peak double-product.