Relative apical sparing of longitudinal strain usingtwo-dimensional speckle-tracking echocardiographyis both sensitive and specific for the diagnosis ofcardiac amyloidosis

Background The diagnosis of cardiac amyloidosis (CA) is
challenging owing to vague symptomatology and nonspecific echocardiographic findings.
Objective To describe regional patterns in longitudinal
strain (LS) using two-dimensional speckle-tracking
echocardiography in CA and to test the hypothesis that
regional differences would help differentiate CA from
other causes of increased left ventricular (LV) wall
thickness.
Methods and results 55 consecutive patients with CA
were compared with 30 control patients with LV
hypertrophy (n¼15 with hypertrophic cardiomyopathy,
n¼15 with aortic stenosis). A relative apical LS of 1.0,
defined using the equation (average apical LS/(average
basal LS + mid-LS)), was sensitive (93%) and specific
(82%) in differentiating CA from controls (area under the
curve 0.94). In a logistic regression multivariate analysis,
relative apical LS was the only parameter predictive of
CA (p¼0.004).
Conclusions CA is characterised by regional variations
in LS from base to apex. A relative ‘apical sparing’
pattern of LS is an easily recognisable, accurate and
reproducible method of differentiating CA from other
causes of LV hypertrophy.