Peak Exercise-to-Recovery Changes in Biventricular Volumes and Function Assessed by Exercise CMR

Background Exercise cardiovascular magnetic resonance (Ex-CMR) assesses cardiac function under physiological stress. Imaging during continuous in-bore exercise best reflects peak physiology but is technically challenging and prone to motion artifacts and patient discomfort. Exercise performed outside the scanner followed by rapid post-exercise imaging improves feasibility and image quality, but the time course of ventricular volume recovery after exercise cessation remains poorly defined. We compared biventricular Ex-CMR measurements during steady-state peak exercise with those acquired sequentially after exercise termination. Methods Ten healthy adults (24 (21-31) years; 8 female) underwent Ex-CMR on a 3T-system. Biventricular volumes were assessed using a free-breathing, ECG-triggered, highly accelerated multi-slice cine sequence with compressed sensing and deep learning–based reconstruction. Short-axis stacks were acquired at rest, during two steady-state peak exercise acquisitions, and at three sequential post-exercise time points, with the first recovery scan beginning 10–15 s after cessation. Linear mixed-effects models evaluated recovery categorically and as a function of elapsed time. Results Differences between repeated peak acquisitions were small (LVEDV +1 ± 3 mL; LVESV −4 ± 7 mL). Immediately after cessation (13 ± 2 s), biventricular volumes remained unchanged versus peak (all p = 1.00). Significant recovery-related changes emerged by 54 ± 9 s and were present for all parameters by 99 ± 18 s. Linear modeling showed LV stroke volume declining 2.1 mL (−1.9%) per 10 s, with similar right-ventricular trends. Post-exercise acquisitions showed higher diagnostic quality and fewer artifacts than in-bore imaging. Conclusion Biventricular volumes measured immediately after exercise closely approximate peak physiology, whereas recovery changes occur rapidly and linearly thereafter. Rapid post-exercise acquisition offers a practical surrogate for peak measurements while improving image quality and feasibility.