Myocardial strain with cardiac magnetic resonance imaging to identify ventricular tachycardia substrate in nonischemic cardiomyopathy: important tool in the toolbox or straining to find value?

Excerpt

Pre-procedural identification of arrhythmogenic substrates can be critical when performing ventricular tachycardia (VT) ablation procedures. This is particularly true in the setting of non-ischemic cardiomyopathy (NICM) which may have complex, patchy, and multifocal scar extending through the endocardial, intramural, and epicardial myocardium. Established techniques using late-gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) or computed tomography rely on assessment of wall thinning, hypokinesis/akinesis, and cardiac-scar deposition; however, these gross structural and functional changes may be preceded by subtler perturbations in myocardial function which can be detected through strain imaging. Strain imaging also affords an opportunity to examine the mechanical properties of distinct myocardial layers by taking advantage of the longitudinal and circumferential distortion during systole. The use of CMR strain imaging in NICM has been validated across other imaging modalities and is gaining a foothold as a meaningful clinical tool [1, 2], but this modality has been underutilized as a tool for electrophysiologists. …