Objective: During cardiovascular stress, if right ventricular (RV) stroke volume exceeds left ventricular (LV) stroke volume, then a large volume of blood is displaced into the pulmonary circulation that may precipitate pulmonary edema. We sought to determine the metrics by which cardiovascular magnetic resonance (CMR) could measure simultaneous displacement of RV and LV stroke volumes during dobutamine stress.
Methods: Thirteen healthy subjects (5 women) aged 53 ± 10 years without medical conditions and taking no medications underwent 2 CMR examinations at 1.5 T separated by 4 to 8 weeks in which RV and LV stroke volumes were determined during intravenous dobutamine and atropine infused to achieve 80% of the maximum predicted heart rate response for age.
Results: The RV and LV stroke volumes were highly correlated at each level of stress (rest: r = 0.98, P = 0.007; low stress: r = 0.87, P = 0.001; and peak stress: r = 0.88, P = 0.001), and the mean difference in SV at each level of stress (rest, low stress, and peak stress was 0 to 2 mL on examinations 1 and 2.
Conclusions: Simultaneous change in right and left ventricular stroke volumes can be assessed in a highly reproducible manner throughout the course of dobutamine CMR stress administered to achieve 80% of maximum predicted heart rate response for age. This technology may help identify discrepancies in RV and LV stroke volumes during cardiovascular stress that are associated with the development of pulmonary edema.
From the Departments of *Internal Medicine (Cardiology Section), †Biomedical Engineering, ‡Public Health Sciences, and §Radiology, Wake Forest School of Medicine, Winston-Salem, NC.
Received for publication April 27, 2011; accepted June 23, 2011.
Reprints: William Gregory Hundley, MD, Cardiology Section, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, North Carolina 27157 (e-mail: firstname.lastname@example.org).
Research was supported in part by NIH R33CA121296, R01HL074330, and the Wake Forest University Claude D. Pepper Older American Independence Center (P30-AG21332).
The authors have no conflict of interest.