What are the typical echo findings in a patient with suspected amyloidosis, particularly those with a history of conditions like multiple myeloma or chronic inflammatory diseases?

Echocardiographic Findings in Cardiac Amyloidosis

Transthoracic echocardiography is the primary and most widely available diagnostic imaging tool for suspected cardiac amyloidosis, providing multiple "red flag" findings that should prompt further diagnostic workup. 1, 2

Structural Abnormalities

The hallmark structural findings on echocardiography include:

• Increased left ventricular wall thickness (≥12 mm) with a small LV cavity size, which is the most characteristic finding 2, 3
• Biatrial enlargement that is disproportionate to the degree of ventricular dysfunction 2
• Increased interatrial septal thickness, which is particularly specific for amyloidosis 4
• Thickened cardiac valves (both atrioventricular and semilunar) without significant stenosis 1, 2
• Pericardial effusion may be present in some cases 1, 2
• Granular sparkling appearance of the myocardium, though this finding is less specific than previously thought 1, 5

Functional and Doppler Abnormalities

Diastolic and systolic dysfunction patterns are critical:

• Restrictive transmitral Doppler filling pattern reflecting severe diastolic dysfunction (grade ≥2) 2
• Reduced ventricular longitudinal strain with characteristic apical sparing pattern - the apex contracts relatively normally while the base is severely impaired 1, 2
• Apical-to-basal strain ratio >2.1 is highly suggestive of cardiac amyloidosis 2
• LV ejection fraction-to-strain ratio >4 is another notable feature 2
• Preserved or mildly reduced ejection fraction in early stages, despite significant wall thickening 5

Critical Diagnostic Clue: Voltage-Mass Discordance

The combination of low QRS voltage on ECG (<0.5 mV in limb leads) with increased LV wall thickness on echocardiography (>12 mm) is highly specific for cardiac amyloidosis and was found in 54% of AL amyloidosis patients. 1, 2, 3 This "voltage-mass mismatch" is one of the most important red flags that should immediately raise suspicion for amyloidosis rather than other causes of left ventricular hypertrophy.

Advanced Echocardiographic Techniques

Speckle-tracking analysis is recommended by multiple international guidelines:

• Longitudinal strain analysis reveals the characteristic apical sparing pattern, where basal and mid-ventricular segments show reduced strain while apical segments are relatively preserved 1, 2
• Global longitudinal strain is typically reduced even when ejection fraction appears preserved 6, 7
• The Integrated Wall Thickness (IWT) echocardiographic score proposed by the European Society of Cardiology, where values ≥8 can be diagnostic of ATTR cardiac amyloidosis when combined with positive bone scintigraphy (Perugini score ≥2) and absence of monoclonal protein 1, 2

Distinguishing Features by Amyloid Type

Echocardiography cannot distinguish AL (light chain) from ATTR (transthyretin) cardiac amyloidosis, and further testing with monoclonal protein screening and/or nuclear imaging is required for subtype determination. 2 However, some patterns may suggest severity:

• AL amyloidosis tends to present with more severe wall thickening and earlier clinical heart failure 3
• AA amyloidosis (associated with chronic inflammatory diseases like rheumatoid arthritis) rarely causes significant cardiac involvement, with only 10% showing the classic echo/ECG pattern compared to 54% in AL amyloidosis 3

Clinical Integration and Next Steps

When echocardiography shows suggestive findings, the American College of Cardiology recommends proceeding immediately with:

• Monoclonal protein screening (serum and urine immunofixation electrophoresis, serum free light chain assay) 2
• Biomarker measurement (NT-proBNP and troponin) 2
• Nuclear imaging with bone tracers (99mTc-PYP/DPD/HMDP) for ATTR diagnosis if monoclonal protein screening is negative 1
• Cardiac MRI when echo is suggestive but equivocal, particularly for tissue characterization 1, 2

Common Pitfalls to Avoid

• Do not dismiss the diagnosis based on preserved ejection fraction alone - cardiac amyloidosis often presents with preserved or only mildly reduced EF despite severe infiltration 5, 6
• Do not attribute wall thickening solely to hypertension or aortic stenosis without considering amyloidosis, especially if there is voltage-mass discordance 2, 4
• Do not rely on the "granular sparkling" appearance alone - this finding has limited sensitivity and specificity and should not be used as a primary diagnostic criterion 5
• Do not assume normal echocardiography excludes early cardiac involvement - strain imaging may detect subclinical disease before conventional parameters become abnormal 6, 7