Table 2.

Tools and its characteristics to raise the suspicion of ATTR-CM.

Tests and hallmarks	Presentation
ECG Pseudo infarct pattern: ECG showing old infarct pattern with low voltage. Commonly seen in ATTRwt (63–65%) and ATTRv (18–69%) Diagnostic yield of 60–65% LVF without any infarction HF with conduction disorders; left BBB, right BBB and first degree AV blocks and other AV blocks Goldberger triad (Low QRS voltage in limb leads, normal voltage in precordial leads, poor R wave progression (V1–V3) RV dysfunction (R wave in aVR, positive T wave in aVR) Isolated AF	[ReferFig. 3A and B]
ECHO Thick-walled LV, RV, RA RCM or hypokinetic nondilated CM Markedly reduced GLS LVEF/Longitudinal strain >4 ‘Bulls eye pattern’ due to apical sparing Apical strain/mid basal strain >3:1 Tissue doppler 5-5-5 sign	[ReferFig. 4A, B, 4C]
CMR
T-1> 1400msec ECV >42% Positive global subendocardial LGE Thick-walled ventricle and atrium Pleural effusion DIR is a type of “black blood" •technique useful for visualizing the walls of the cardiac chambers •and blood vessels (including the coronary arteries) •Abnormal gadolinium kinetics typical for amyloidosis, myocardial nulling prior to blood pool nulling	[ReferFig. 5A and B]
Biochemical marker: persistent increase in the levels of Troponin T > 0.05 ng/mL, NT-proBNP >3000 pg/mL
Bone scintigraphy
Semi-quantitative visual Grade of 2 or 3, target to background (LV myocardium to blood pool) ratio >1.5 and retention index >0.030/min. If cardiac uptake is Grade 1, histological confirmation of amyloid deposits (could be extracardiac) is required as non-invasive diagnosis is not possible.	[ReferFig. 6]
Hematology
Serum free kappa: lambda light chain ratio >3 and free light chain>18 mg/dL is suggestive to go for hematological testing; immunofixation electrophoresis of urine and serum

AF, atrial fibrillation; ATTRv, hereditary ATTR-CM; ATTRwt, wild-type ATTR-CM; AV, atrioventricular; aVR, augmented vector right; BBB, bundle branch block; CM, cardiomyopathy; CMR, cardiac magnetic resonance; DIR, double inversion recovery; ECG, electrocardiogram; ECHO, echocardiography; ECV, extracellular volume; GLS, global longitudinal strain; HF, heart failure; LGE, late gadolinium enhancement; LV, left ventricle; LVEF, left ventricular ejection fraction; LVF, left ventricular failure; NT-proBNP, N-terminal pro B-type natriuretic peptide; RA, right atrium; RV, right ventricle; RCM, restrictive cardiomyopathy.