Fig. 4

Example of LV pressures and volumes in a naïve animal, measured in the CMR environment (black) and with a conductance PV loop conductance catheter (gray). Corresponding illustrations of end-diastole and end-systole time points are shown in red and blue, respectively. A LV pressure measured with a fluid-filled catheter in the CMR environment and with a conductance PV loop catheter. Damping was visible in systole and diastole in the fluid-filled pressure measurement. B LV volume measured with short-axis-stack CMR (dashed black line), long-axis real-time CMR, and a PV loop catheter. Volumes measured with real-time CMR were comparable to reference standard short-axis-stack over the entire cardiac cycle, while the PV loop catheter measured larger volumes despite being calibrated using short-axis CMR volumes. C PV loops derived from combined pressure and volumes measurements in the CMR environment using real-time long-axis volumes, and with a PV loop catheter