Cardiac magnetic resonance myocardial feature tracking detects quantitative wall motion during dobutamine stress

Methods 10 healthy subjects were studied at 1.5 Tesla. Myocardial strain parameters were derived from SSFP cine images using dedicated CMR-FT software (Diogenes MRI prototype, Tomtec, Germany). Right ventricular (RV) and left ventricular (LV) longitudinal strain (EllRV and EllLV) and LV long-axis radial strain (ErrLAX) were derived from a 4-chamber view at rest. LV short-axis circumferential strain (EccSAX) and ErrSAX, LV ejection fraction (EF) and volumes were analyzed at rest and during dobutamine stress (10 and 20 μg * kg-1* min-1). Results In all volunteers strain parameters could be derived from the SSFP images at rest and stress. EccSAX values showed significantly increased contraction with DSMR (rest: -24.1±6.7; 10 μg: -32.7±11.4; 20 μg: -39.2±15.2, p<0.05). ErrSAX increased significantly with dobutamine (rest: 19.6±14.6; 10 μg: 31.8±20.9; 20 μg: 42.4±25.5, p<0.05). In parallel with these changes, EF increased significantly with dobutamine (rest: 56.9±4.4%; 10 μg: 70.7 ±8.1; 20 μg: 76.8±4.6, p<0.05). Observer variability was best for LV circumferential strain (EccSAX ) and worst for RV longitudinal strain (EllRV) as determined by 95% confidence intervals of the difference.