Cardiac Amyloidosis on EchoCG: Apical Sparing, Wall Thickness, Granularity
Wall Thickness and Overall Morphology
Classic EchoCG signs of amyloidosis include increased wall thickness of both ventricles, poor function along the long axis, relative preservation of apical longitudinal contractility, and reduced global longitudinal strain (British Society of Echocardiography, 2021). A characteristic discrepancy exists between the degree of LVH on EchoCG and the low voltage amplitude on ECG.
Thickening of the interatrial septum (>0.5 cm) due to amyloid deposition is a characteristic sign (Transthyretin amyloidosis, 2023). Pericardial effusion occurs in more than 50% of patients; it is nonspecific but often accompanies the picture — standard views should be used to assess size, location, and hemodynamic significance.
Apical Sparing: Quantitative Criteria
Speckle-tracking of the LV in amyloidosis demonstrates a characteristic apical sparing phenotype on the polar map of longitudinal strain, unlike in hypertensive heart disease, HCM, and aortic stenosis (ASE, 2025). Several ratios have been proposed for assessment:
| Indicator | Threshold Value |
|---|---|
| Apical strain to mid and basal strain ratio | >1 |
| Septal apical-to-basal ratio (in four-chamber view) | >2.1 |
| EF/strain ratio | >4.1 |
Relative apical preservation of longitudinal strain in 2D speckle-tracking is sensitive and specific for diagnosing cardiac amyloidosis (Phelan et al., according to ASE/BSE). However, the pattern itself is not pathognomonic for amyloid (British Society of Echocardiography, 2021).
Myocardial Granularity
[clarify] — in the source fragments, quantitative or qualitative criteria for the "granular" appearance of the myocardium are not provided.
Differential Diagnosis and Variability
Suggestive signs — increased LV wall thickness, reduced GLS with a typical apical sparing pattern, restrictive transmitral flow, and restrictive TDI pattern of the mitral annulus — do not differentiate AL-CM from ATTR-CM; there is significant overlap (Transthyretin amyloidosis, 2023). It is recommended to indicate the probability of amyloidosis in the conclusion but not to comment on the subtype. Inter-vendor variability in the assessment of apical sparing should be considered (ASE/EACVI, 2024).
Frequently asked questions
What quantitative thresholds for apical sparing are used?
Apical strain to mid and basal strain ratio >1, septal apical-to-basal ratio >2.1, and EF/strain ratio >4.1 (ASE, 2025).
Is apical sparing pathognomonic for amyloidosis?
No. Relative apical preservation of strain is sensitive and specific but, according to BSE (2021), not pathognomonic for amyloid.
What indicates thickening of the interatrial septum?
Thickening of the interatrial septum >0.5 cm due to amyloid deposition is a characteristic sign of cardiac amyloidosis (Transthyretin amyloidosis, 2023).
Can EchoCG distinguish AL from ATTR?
No. Suggestive signs do not differentiate AL-CM from ATTR-CM; it is recommended to indicate the probability of amyloidosis without commenting on the subtype.
How common is pericardial effusion?
In more than 50% of patients with cardiac amyloidosis, however, the sign is nonspecific (Transthyretin amyloidosis, 2023).