Can regional strain and strain rate measurement be performed during both dobutamine and exercise echocardiography, and do regional deformation responses differ with different forms of stress testing?

BACKGROUND: Regional strain (epsilon) and strain rate (SR) measurement could be the optimal approach to quantifying stress echocardiography images. However, signal noise could preclude their use. Study aims Our aim was to compare the feasibility of regional peak systolic (p) velocity (Vel), pSR/epsilon measurement, and their normal responses during upright (group 1, n = 10) and supine (group 2, n = 10) bicycle exercise and (group 3, n = 10) dobutamine stress.
METHODS: For each type of stress study, pVel/pSR/epsilon data were acquired at baseline, low (100-120 bpm), and peak (140-160 bpm) heart rate (HR); and during recovery.
RESULTS: During dobutamine pVel/pSR/epsilon were interpretable in >95% of segments at every stress stage, whereas in groups 1 and 2 pSR/epsilon responses were noninterpretable in >36% of segments (P <.0002). The highest proportions of data exclusions were from the lateral and anterior walls. In all groups, regional systolic pVel and SR values increased linearly and reached maximal value at peak HR (P <.0006 vs baseline). Pepsilon showed a biphasic response, initially increasing at low HR, and then remaining constant or falling at peak HR.
CONCLUSION: PSR/pepsilon quantification of stress echocardiography may currently be restricted to dobutamine as increased signal noise precludes adequate data acquisition during exercise. For all forms of stress both pSR and pVel increased linearly, whereas pepsilon response was biphasic as a result of the reduced filling at higher HRs.