Echocardiographic Diagnosis of Cardiac Amyloidosis and Hypertrophic Cardiomyopathy

Cardiac Amyloidosis

The European Society of Cardiology recommends that granular sparkling myocardial appearance and thickened heart valves are key features to distinguish cardiac amyloidosis from hypertrophic cardiomyopathy 1, 2
Concentric left ventricular hypertrophy with symmetrically thickened walls, typically without cavity dilation, is a characteristic feature of cardiac amyloidosis 1, 2
Increased interatrial septum thickness (>6 mm) is highly specific for amyloidosis 1, 2
Thickened atrioventricular valve leaflets (mitral and tricuspid) are commonly seen in cardiac amyloidosis 1, 2
Increased right ventricular free wall thickness distinguishes amyloidosis from isolated HCM 1, 2
Biatrial enlargement despite relatively preserved ventricular cavity size is a feature of cardiac amyloidosis 3
Restrictive filling pattern with E/A ratio ≥2 and E-wave deceleration time ≤150 ms is characteristic of cardiac amyloidosis 1
Mildly reduced ejection fraction (typically 40-50%) with restrictive physiology contrasts with hyperdynamic function in HCM 1, 2
Severely reduced longitudinal strain affecting all segments globally, with relative apical sparing creating a "bulls-eye" pattern, is seen in cardiac amyloidosis 3

The American College of Cardiology recommends that maximal LV wall thickness ≥15 mm (or ≥13-14 mm in family members with confirmed HCM) measured anywhere in the left ventricle is diagnostic of HCM 4, 5
Asymmetric septal hypertrophy is the most common pattern involving basal anterior septum and anterior free wall 4, 5
Systolic anterior motion (SAM) of the mitral valve with mitral-septal contact is highly specific for HCM 1, 4, 5
Left ventricular outflow tract obstruction with gradient ≥30 mmHg at rest or with provocation (Valsalva, standing, exercise) is a feature of HCM 1, 2, 7
Normal or hyperdynamic ejection fraction (typically >65%) contrasts with mildly reduced EF in amyloidosis 1, 2
Abnormal diastolic function with elevated E/e' ratio indicating elevated filling pressures is seen in HCM 1, 2
Restrictive filling pattern (E/A ≥2) in advanced cases indicates poor prognosis 1