Non-invasive evaluation of the myocardial substrate of cardiac amyloidosis by gadolinium cardiac magnetic resonance

Objective: To investigate the prevalence and distribution of gadolinium (Gd) enhancement at cardiac magnetic resonance (CMR) imaging in patients with cardiac amyloidosis ( CA) and to look for associations with clinical, morphological, and functional features. Patients and design: 21 patients with definitely diagnosed CA ( nine with immunoglobulin light chain amyloidosis and 12 transthyretin related) underwent Gd-CMR. Results: Gd enhancement was detected in 16 of 21 (76%) patients. Sixty six of 357 (18%) segments were enhanced, more often at the mid ventricular level. Transmural extension of enhancement within each patient significantly correlated with left ventricular (LV) end systolic volume (r = 0.58). The number of enhanced segments correlated with LV end diastolic volume ( r = 0.76), end systolic volume ( r = 0.6), and left atrial size ( r = 0.56). Segments with. 50% extensive transmural enhancement more often were severely hypokinetic or akinetic ( p = 0.001). Patients with. 2 enhanced segments had significantly lower 12 lead QRS voltage and Sokolow- Lyon index. No relation was apparent with any other clinical, morphological, functional, or histological characteristics. Conclusion: Gd enhancement is common but not universally present in CA, probably due to expansion of infiltrated interstitium. The segmental and transmural distribution of the enhancement is highly variable, and mid-ventricular regions are more often involved. Enhancement appears to be associated with impaired segmental and global contractility and a larger atrium.