DOBUTAMINE-ATROPINE STRESS ECHOCARDIOGRAPHY IN ASYMPTOMATIC HEALTHY-INDIVIDUALS - THE RELATIVITY OF STRESS-INDUCED HYPERKINESIA

Background Interpretation of dobutamine-atropine stress echocardiograp hy (DASE) is based on the assumption that the normal response to dobut amine-atropine infusion is characterized by increased systolic thicken ing and motion of the left ventricular (LV) walls, whereas a reduction or no change is considered indicative of coronary artery disease. The aim of this study was to quantitatively assess changes in LV dimensio n and wall motion patterns during DASE in a healthy population. Method s and Results Forty-two asymptomatic voluntary subjects (22 men) with a mean age of 59 years (range, 31 to 79 years) and a likelihood of <5% for coronary artery disease underwent DASE with digital recording of two-dimensional and M-mode echocardiography at baseline and low-dose a nd peak infusion rates. Mean end-diastolic and end-systolic LV diamete rs and areas decreased and wall thicknesses increased progressively th roughout the test. Wall motion and thickening increased from baseline to low-dose infusion in nearly all subjects. However, from low-dose to peak infusion, the mean absolute wall motion and relative wall thicke ning decreased by 13.1% (95% CI, 2.7 to 23.5) and 21.4% (95% CI, 6.4 t o 36.4) regardless of age, sex, or use of atropine. Changes in fractio nal shortening and absolute wall thickening varied considerably, with a decrease observed in 15 and 13 individuals (36% and 31%), respective ly. Conclusions In healthy subjects, measures of wall motion and wall thickening increased from baseline to low-dose infu sion but decreased from low-dose to peak infusion. These Endings call for revision of th e assumptions on which the common analysis of DASE is based.