IS Case 160: Cardiac amyloidosis

Jerry Lee, MD


Imaging Sciences URMC 2008
Publication Date: 2009-05-21

History

Patient is a 74-year-old male with a history of hypertension, hyperlipidemia and non-schemic cardiomyopathy presenting with dyspnea.

Findings

Cardiac MRI shows diffusely thickened myocardium of the left ventricle. Cardiac cine demonstrates circumferential hypokinesis of the left ventricle. LVEF is 16%. No valvular abnormalities identified. Delayed gadolinium enhanced MDE images demonstrate diffuse enhancement of the myocardium.

Diagnosis

Cardiac amyloidosis

Discussion

Amyloidosis frequently involves the heart and is a common cause of secondary restrictive cardiomyopathy. Deposition of amyloid fibrils occurs in myocardial tissue, valve leaflets and myocardial vessels. The clinical presentation varies and may mimic other infiltrative cardiomyopathies such sarcoidosis or hypertropic cardiomyopathy. The therapeutic means are limited and treatment is generally unsatisfactory. The diagnosis is important to exclude the potentially curable conditions that it may mimic.

Cardiac MRI demonstrates homogeneously increased thickness of ventricular and atrial walls. The ventricular cavities have a normal or reduced size. The increase in myocardial wall thickness in cardiac amyloidosis may mimic hypertropic cardiomyopathy. The atria are usually enlarged due to diastolic dysfunction and/or valvular dysfunction due to amyloid deposition. Pleural and pericardial effusions are not infrequently seen. The cardiac amyloid deposits generally cause severe cardiac dysfunction with a poor prognosis and it is generally considered that CHF is predominantly a diastolic phenomenon with systolic dysfunction occurring late in the disease. On delayed post-contrast images, widespread heterogeneous enhancement of the myocardium is often seen. In the article by vanden Driesen, et al. [2], the common imaging findings specific to amyloid cardiomyopathy are features of restrictive cardiomyopathy such as LV wall thickening, reduced systolic function with decreased ejection fraction, restriction of diastolic filling, disproportionate atrial enlargement, and widespread heterogeneous delayed enhancement.

References

  1. Bogaert J, Dysmarkowski S, Taylor AM. Clinical Cardiac MRI. Springer, 2005
  2. vanden Driesen R, Slaughter R, Strugnell W. MR findings in cardiac amyloidosis. AJR Am J Roentgenol. 2006 Jun;186(6):1682-5. [PMID: 16714659]

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