Time to target heart rate in dobutamine stress echocardiography is shortened by using dynamic, but not isometric handgrip

Abstract Background Dobutamine stress echocardiography (DSE) is widely used for the detection of obstructive ischaemic heart disease. In our previous study we demonstrated that the magnitude of myocardial injury measured by hsTnT is associated with DSE duration. Shortening of DSE time is therefore desirable. Use of hangrip (HG) during DSE is generally recommended. However, there are no published studies comparing the efect of dynamic and isometric HG on the length of DSE. Purpose To compare the effect of dynamic and static HG on DSE duration. Methods 211 patients undergoing DSE for ischaemia assessment were randomised into no HG (noHG, n=74), isometric HG (isoHG, n=68) and gynamic HG (dynHG, n=69) groups. All patients taking rate limiting medication were instructed to stop it 48 hours prior the test. DSE was performed according to the standard protocol (dobutamine infusion 5, 10, 20, 30, 40 ug/kg/min., increased in 3 min. intervals). HG was applied at the level of 40% maximum isometric muscular effort from the dobutamine dose of 20ug/kg/min. and atropine was administered in 1 min. intervals in 100 ug increments from the dose of 30 ug/kg/min. Patients who did not achieve their target heart rate (HR) or suffered from dobutamine side effects were excluded from the study. Results There were no differences in the groups characteristics (gender p=0.187, known ischaemic heart disease p=0.361, age p=0.128, basal HR p=0.367, target HR p=0.107, achieved HR p=0.257, positive test for ischaemia p=0.583). There was a significant difference in the time to target HR between dynHG and noHG groups (9.97±2.34 vs 11.96±3.02 min., p< 0.001) but not between isoHG and noHG groups (10.76±3.12 vs 11.96±3.02 min., p=0.058). Also, the was a similar difference in the length of dobutamine infusion between dynHG and noHG, but not between isoHG and noHG groups (11.76±2.37 vs 13.78±3.09 min., p< 0.001 and 13.34±4.90 vs 13.78±3.09 min., p=0.308, respectively). No significant correlation was found between the time to target HR and basal (r=0.43) or target HR (r=0.38). Conclusion Dynamic, but not isometric handgrip shortens the length of dobutamine stress echocardiography.