Effect of hydration status on atrial and ventricular volumes and function in healthy adult volunteers

Background Assessment of cardiac chamber volumes is a fundamental part of cardiac magnetic resonance (CMR) imaging. While the effects of inter- and intraobserver variability have been studied and have a recognized effect on the comparability of serial cardiac MR imaging studies, the effect of differences in hydration status has not been evaluated. Objective To evaluate the effects of volume administration on cardiac chamber volumes. Materials and methods Thirteen healthy adults underwent a baseline cardiac MR to evaluate cardiac chamber volumes after an overnight fast. They were then given two saline boluses of 10 ml/kg of body weight and the cardiac MR was repeated immediately after each bolus. Results From the baseline scan to the final scan there was a significant increase in all four cardiac chamber end-diastolic volumes. Right atrial volumes increased 8.0%, from 61.1 to 66.0 ml/m2 ( P <0.001), and left atrial volumes increased 10.0%, from 50.0 to 55.0 ml/m2 ( P <0.001). Right ventricular volumes increased 6.0%, from 91.1 to 96.5 ml/m2 ( P <0.001), and left ventricular volumes increased 3.2%, from 87.0 to 89.8 ml/m2 ( P <0.001). Conclusion Hydration status has a significant effect on the end-diastolic volumes of all cardiac chambers assessed by cardiac MR. Thus, hydration represents a “variable” that should be taken into account when assessing cardiac chamber volumes, especially when performing serial imaging studies in a patient.