Abstract 18893: Real-time B-mode Cardiac Time-harmonic Elastography for the Detection of Diastolic Dysfunction
Introduction: Cardiac MR elastography (cMRE) has recently been shown sensitive to diastolic dysfunction. cMRE measures the periodic alteration of the myocardial shear modulus based on externally induced low-frequency acoustic vibrations produced by a loudspeaker. It was demonstrated that shear wave amplitudes are reduced in patients with pathologically increased myocardial stiffness. Purpose of this feasibility study is to adopt the principles of cMRE by fast and cost-efficient cardiac time-harmonic elastography (cTHE) guided by transthoracic echocardiography.
Methods: cTHE was implemented into a commercial ultrasound B-mode scanner connected to an examination couch designed to introduce 30-Hz continuous vibrations into the patient’s chest. The alteration of shear wave amplitudes was displayed in real time after placement of the elastographic processing window of 1- 2 cm width by B-mode guidance. In a group of 9 healthy volunteers and two patients with mild and moderate diastolic dysfunction, we focused on the lateral wall of the left ventricle to record shear wave amplitudes and wall motion.
Results: Wall motion and shear wave amplitudes of the left ventricle’s lateral wall were successfully recorded repeatedly for ten consecutive seconds. In agreement to cMRE, wave amplitudes are lower in systole than in diastole due to higher myocardial stiffness (Figure 1, A). Measurement of the two patients with diastolic dysfunction showed a delay of the increase of wave amplitudes from systolic to diastolic level in relation to cardiac wall motion compared to the healthy volunteers (Figure 1, B).
Conclusions: Real time cTHE is a novel modality to measure changes in shear wave amplitudes. Myocardial tension and the corresponding wall motion can be determined directly in order to potentially identify patients with diastolic dysfunction.
- Diastolic function
- Myocardial contraction
- Pressure – volume relation
- Ventricular function
Author Disclosures: R. Hättasch: None. H. Tzschaetzsch: None. F. Knebel: None. T. Elgeti: None. M. Schultz: Ownership Interest; Modest; Development and marketing of ultrasound systems. R. Klaua: Ownership Interest; Modest; Development and marketing of ultrasound systems. J. Braun: None. I. Sack: None.
- © 2014 by American Heart Association, Inc.