Fig. 1

Dynamic pressure–volume (PV) loops were acquired during preload alteration challenge by inferior vena cava (IVC) occlusion. 1 Extraction of the portion of the pressure and electrocardiogram (ECG) signals recorded simultaneously to imaging were detected from the cardiovascular magnetic resonance (CMR) gradient activity (grey rectangle). 2 In the first ten heartbeats post balloon inflation, end-diastole (red) was detected from the R peaks in the ECG and end-systole (blue) as the onset isovolumic relaxation in the pressure signal. 3 3D left ventricular (LV) volume was derived from long-axis segmentations. End-diastole and end-systole were detected as the maximum and minimum volumes, respectively. 4 PV loops were derived by pairing pressure and volume. Contractility and compliance were derived from the slopes of the end-systolic pressure–volume relationship (ESPVR) and end-diastolic pressure–volume relationship (EDPVR) linear fits, respectively