Cardiac Amyloidosis: Sensitivity and Specificity

Introduction: Amyloidosis represents abnormal deposition of amyloid fibrils within the soft tissues. It can affect various organs, including the heart where it deposits in the myocardium. Clinical features are those of diastolic Congestive Heart Failure.

Note that the diagnosis of systemic amyloidosis can be obtained by biopsy of other involved organs (though this does not necessarily prove cardiac involvement, which has a worse prognosis).

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Tags: Cardiac Problem Hematologic Tag this Diagnosis.

The sensitivity and specificity of findings for Cardiac Amyloidosis are listed below. See the left navigation bar to change the display.

Sensitive and Specific Findings

Cardiac MRI

88%

90%

another, smaller, study had sensitivity of 80% and specificity of 94%. Gold standard: endomyocardial biopsy.

Findings on cardiac MRI are diffuse subendocardial delayed enhancement. Endomyocardial enhancement may be patchy, instead, but not in a vascular distribution. Another imaging feature is diffusely hypointense blood pool due to absorption of gadolinium by amyloid throughout the body.

Study: JACC Cardiovasc Imaging. 2009 Dec;2(12):1369-77. PMID: 20083070

J Am Coll Cardiol. 2008 Mar 11;51(10):1022-30. PMID: 18325442

Specific Findings

Speckled Myocardium

26%

96%

on Trans-Thoracic Echocardiography. Also known as "granular myocardium."

Study: J Am Coll Cardiol. 2004 Feb 4;43(3):410-5. PMID: 15013123

Low ECG Voltage

56%

87%

in patients referred for endomyocardial biopsy

Study: J Am Coll Cardiol. 2004 Feb 4;43(3):410-5. PMID: 15013123

JACC Cardiovasc Imaging. 2009 Dec;2(12):1369-77. PMID: 20083070

Poorly Diagnostic Findings

ECG

60%

64%

Pseudo-infarct pattern (pathologic q waves without CAD)

Study: J Am Coll Cardiol. 2004 Feb 4;43(3):410-5. PMID: 15013123

Trans-Thoracic Echocardiography

Sensitivity = 47%

Diastolic dysfunction: specifically, "advanced (pseudonormal or restrictive) diastology." However, other diseases can cause diastolic dysfunction, especially hypertrophic cardiomyopathy such as from hypertension.

Study: JACC Cardiovasc Imaging. 2009 Dec;2(12):1369-77. PMID: 20083070

Findings With Unspecified Accuracy

Endomyocardial Biopsy

No accuracy specified.

Gold-standard test, although clinically significant disease can be missed if patchy. Sources quote "virtually 100% sensitivity."

Study: JACC Cardiovasc Imaging. 2009 Dec;2(12):1378-80. PMID: 20083071

Circulation. 2005 Sep 27;112(13):2047-60. PMID: 16186440