== Echo == [[https://heart.bmj.com/content/98/19/1442.short|Relative apical sparing of longitudinal strain using two-dimensional speckle-tracking echocardiography is both sensitive and specific for the diagnosis of cardiac amyloidosis 2012]] [[https://heart.bmj.com/content/102/10/748.short|Prognostic implication of relative regional strain ratio in cardiac amyloidosis 2019]]