A. Chatterji, Department of Internal medicine, Western Isles Hospital,
Stornoway, Isle of Lewis.
Corresponding author: A Chatterji, Consultant physician, Department of
medicine,
Email: achatterji@doctors.org.uk
SMJ 2009 54(1): 58
Abstract
Pericardial
effusion in hypothyroidism is common. But an effusion which causes cardiac
tamponade is a rarity. Reported below is a case with myxedema and cardiac
tamponade due to pericardial effusion.
Key Words: Hypothyroidism, Cardiac tamponade
Case
Report
A 56-year-old man presented with progressive shortness of breath and generalised swelling of a few months duration to the Western Isles Hospital in Stornoway. This is a rural district general hospital with 76 acute medical beds catering to the population of the Western Isles. On examination, he was haemodynamically stable though with a raised jugular venous pulse, muffled heart sounds, basal crackles in the chest and presence of pulsus paradoxus. Chest X ray showed a globular heart (see figure 1) and there were low voltage complexes on the ECG.
Figure 1: Chest X ray suggestive of a large pericardial effusion.
Echocardiogram showed a large pericardial effusion with right atrial and right ventricular collapse suggesting pericardial tamponade1 (figure 2). Therapeutic pericardiocentesis was done and 300 ml of straw colored fluid was drained which proved to be transudative on biochemistry and had a negative cytology. Post pericardiocentesis he was clinically better and the Echocardiogram showed a diminution of the pericardial effusion with absence of signs of tamponade (figure 3).
Figure 2 Showing collapse of the right ventricle in diastole suggestive of tamponade
Figure 3 Post pericardiocentesis there was a diminution of the size of the effusion.
He turned out to be hypothyroid with a TSH of 51. He was started on thyroxine and has done well ever since.
Discussion
Cardiac tamponade is life-threatening, slow or rapid compression of the heart due to the pericardial accumulation of fluid, pus, blood, clots, or gas, as a result of effusion, trauma, or rupture of the heart. Tamponade is more common in patients with malignant pericarditis. Less common causes include tuberculosis, acute MI, pericarditis, radiation damage, bacterial infection, cardiomyopathy, lupus, dissecting aortic aneurysm etc. Other causes include iatrogenic trauma like central line placement, pacemaker insertion, cardiac catheterization, sternal bone marrow biopsies, and pericardiocentesis.
Myxedema heart disease as a distinct entity was first described by Zondek2 in 1918 and defined completely by Fahr3 in 1925. Kern 4 described pericardial effusion as a "constant, early and major factor in myxedema heart." Hypothyroidism is associated with increased capillary permeability and impaired lymphatic drainage with subsequent leakage of protein into the interstitial space, resulting in pericardial effusion, a common clinical finding in overt hypothyroidism. The incidence has been reported as between 30% and 80% in several studies5,6. The rarity of cardiac tamponade7,8 in myxedema patients with pericardial effusion is attributed to the slow accumulation of fluid and the remarkable distensibility of the pericardium.
Conclusion:
The
diagnosis of hypothyroidism is frequently overlooked. It is important therefore,
to carry out appropriate tests for thyroid function as well as
echocardiography in patients with an enlarged cardiac silhouette of
undetermined origin.
References:
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3.
Fahr G, Myxedema heart. J. Amer. Med. Assoc, 84: 345-349, 1925.
4.
Kern R A, Soloff L A, Shap W J et al, Pericardial effusion; A constant, early
and major factor in the cardiac syndrome of hypothyroidism (Myxedema heart).
Amer. J. Med. Sci, 217: 609-618, 1949.
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