Hemochromatosis (cardiac manifestations)
Cardiac involvement in hemochromatosis typically occurs with primary hemochromatosis, as the organ is usually spared in the secondary form of the disease.
For a general discussion, and for links to other system specific manifestations, please refer to the article on hemochromatosis.
Epidemiology
Cardiac involvement occurs in approximately 15-20% of the patients with hemochromatosis.
Clinical presentation
Manifestations depend on the extent of iron deposition and include:
- breathlessness
- pedal edema
- palpitations
- features of congestive heart failure
Pathology
Hemochromatosis can result in an iron overload cardiomyopathy.
Radiographic features
Echocardiography
Transthoracic echocardiography is a useful screening tool for the presence of cardiac manifestations in patients with known hemochromatosis. Findings are, however, nonspecific, and may be loosely divided into early and late findings :
- early findings
- diastolic dysfunction
- grade II - III dysfunction typical (formerly referred to as the pseudonormal and restrictive filling profiles, respectively)
- left atrial enlargement
- diastolic dysfunction
- advanced findings
- the "dilated" phenotype
- left and right ventricular chamber enlargement
- decreased left ventricular systolic function
- the "restrictive" phenotype
- grade III diastolic dysfunction
- formerly referred to as restrictive filling
- mitral filling velocity profile demonstrates an E/A ratio > 2 with a deceleration time (DT) < 160 ms
- severe left atrial enlargement
- right ventricular dysfunction
- elevated right ventricular systolic pressure (RVSP)
- elevated systolic pulmonary artery pressure (sPAP)
- normal to elevated left ventricular ejection fraction
- grade III diastolic dysfunction
- the "dilated" phenotype
Decreased peak velocities of the left ventricular lateral wall, as measured by speckle tracking echocardiography, may occur before the aforementioned early findings on B-mode/dopper echocardiography .
MRI
The role of cardiac MRI (CMR) is to identify and quantify the amount of iron deposition. Paramagnetic ferritin and hemosiderin lead to altered relaxation times of adjacent hydrogen nuclei. T2* imaging is highly sensitive in detecting the amount of iron deposition. T2* CMR is also a recent advancement in the evaluation of cardiac iron overload.
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