Tagged cine magnetic resonance imaging to quantify regional mechanical changes after acute myocardial infarction

Abstract

Purpose:The conventional volumetric approaches of measuring cardiac function are loaddependent, and are not able to discriminate functional changes in the infarct, transition and remote myocardium. We examined phase-dependent regional mechanical changes in the infarct, transition and remote regions after acute myocardial infarction (MI) in a preclinical mouse model using cardiovascular magnetic resonance imaging (CMR). Methods:We induced acute MI in six mice with left anterior descending coronary artery ligation. We then examined cardiac (infarct, transition and remote-zone) morphology and function utilizing 9.4 T high field CMR before and 2 weeks after the induction of acute MI. Myocardial scar tissue was evaluated by using CMR with late gadolinium enhancement (LGE). After determining global function through volumetric analysis, regional wall motion was evaluated by measuring wall thickening and radial velocities. Strain rate imaging was performed to assess circumferential contraction and relaxation at the myocardium, endocardium, and epicardium.Results: There was abnormal LGE in the anterior walls after acute MI suggesting a successful MI procedure. The transition zone consisted of a mixed signal intensity, while the remote zone contained viable myocardium. As expected, the infarct zone had demonstrated severely decreased myocardial velocities and strain rates, suggesting reduced contraction and relaxation function. Compared to pre-infarct baseline, systolic and diastolic velocities (v S and v D ) were significantly reduced at the transition zone (v S : −1.86±0.16 cm/s vs −0.68±0.13 cm/s, P < 0.001. v D : 1.86±0.17 cm/s vs 0.53±0.06 cm/s, P < 0.001) and remote zone (v S : −1.86±0.16 cm/s vs −0.65±0.12 cm/s, P < 0.001. v D : 1.86±0.16 cm/s vs 0.51±0.04 cm/s, P < 0.001). Myocardial peak systolic and diastolic strain rates (SR S and SR D ) were significantly lower in the transition zone

Correlation of Myocardial Strain and Late Gadolinium Enhancement by Cardiac Magnetic Resonance After a First Anterior ST-Segment Elevation Myocardial Infarction

“…Götte et al compared regional function between the infarcted and remote region and found significant differences by CMR tissue tagging but not by wall thickening analysis (11). An animal study, quantifying regional mechanical changes 2 weeks after index procedure by tagged cine, also presented similar results, in which circumferential strain was −1.5 ± 0.5%, −4.5 ± 0.8%, and −5.5 ± 1.4% in infarct zone, transition zone, and remote zone, respectively (direct comparison was not performed) (28). Our study performed in a larger human population and by a more convenient method (CMR feature-tracking) showed that strains in adjacent region were better than infarcted region and worse than remote region.…”

Biventricular Strain Imaging with Cardiac MRI in Genotyped and Histology Validated Amyloid Cardiomyopathy

“…Then, delayed enhanced images were obtained 2–10 min after intravenous (IV) gadolinium injection (Omniscan 0.1 mmol/kg) using previously validated inversion recovery pulse sequence. The TI Cardiac function and strain imaging was performed by using Segment version 3.1 R8123 ( http://segment.heiberg.se accessed on 15 June 2020), as described previously by our group [ 14 - 18 ].…”

“…Strain analysis was conducted on amyloidosis patients using principles from finite strain theory, as described previously [ 14 ]. Cardiomyocyte contraction was evaluated by using one-dimensional Lagrangian strains ( ε ) along the circumferential, radial and longitudinal directions, which are defined by the following formula [ 19 ]: where L is the length of the myocardial segment and L 0 is the original length at end diastole.…”

CMR for myocardial characterization in ischemic heart disease: state-of-the-art and future developments

“…Each motion pattern is related to a different myocardial layer, which allows the derivation of the location and severity of the impairment [ 15 ]. Strain imaging has shown its incremental value to improve diagnosis and quantification of wall motion disturbances in acute and chronic ischemic cardiomyopathy in preclinical animal models [ 16 ] and human studies [ 17 – 19 ]. Recent publications demonstrated the incremental prognostic value of strain imaging in risk stratification after myocardial infarction [ 20 – 23 ].…”