The Spectrum of Echocardiographic Abnormalities in Hypothyroidism and the Effect of Hormonal Treatment

Abstract

Cross-sectional echocardiography was used to identify and quantify different cardiac abnormalities in 85 patients with hypothyroidism. Pericardial effusion was the most common and was found in 32 patients (37.6%), while abnormal increase in left ventricular dimensions with impairment of function followed next in frequency (16.4%). Asymmetrical septal hypertrophy as well as segmental wall motion abnormality were each detected in 11.76%. Holosystolic prolapse of the mitral valve was present in only 4.7% of the cases. Different combinations of abnormalities were observed in a total of 22 patients (25.76%), and pericardial effusion was a constant finding. Some of the abnormalities were reversed with physiological thyroxin replacement, but abnormal regional abnormal wall motion remained unimproved. The notion that the heart could be affected in hypothyroidism is at least a hundred years old, but the concept of a myxedema heart was first proposed by Zondek [1] in 1918. This concept was further advanced by Fahr [2] and Kern et al [3] in their clinical studies. Kern et al attributed most of the cardiac features of hypothyroidism to the presence of pericardial effusion, namely: clinical cardiomegaly, distant heart sounds, radiological enlargement of the heart, and low-voltage QRS complex on the electrocardiogram. For a long time thereafter, there was disagreement as to whether all the findings in myxedema heart were due to pericardial effusion or there was an associated intrinsic cardiac muscle abnormality, i.e., a cardiomyopathy. Early autopsy studies indicated the existence of structural abnormalities in the myocardium [4,5].Hemodynamic techniques [6] and noninvasive methods such as systolic time intervals [7] were subsequently used to demonstrate depressed myocardial contractility with reduced stroke volume and low cardiac output in untreated hypothyroidism. Kerber and Sherman [8] were perhaps the first to systematically use echocardiography to demonstrate pericardial effusion in hypothyroidism, while Santos et al [9] first used this method to draw attention to other types of cardiac abnormality, such as asymmetrical septal thickening.Subsequently, there have been several publications on the echocardiographic findings in adults with hypothyroid [10,12], as well as children [13,14] and even neonates [15] with the condition. However, some of these studies had a relatively small number of patients [10,12], relied only on M-mode echocardiography [10,11], or focused primarily on pericardial effusion [9][10][11].In the present report, which we believe is the first such study in an Arab population, both M-mode and twodimensional echocardiography were used to evaluate a large number of hypothyroid patients for the purpose of establishing not only the spectrum of abnormalities in the pericardium, myocardium, and valvular apparatus, but also the effect of hormonal treatment on the detected abnormalities.

Hypothyroidism Causing Pericardial Effusion: A Case Report

“…Most of the clinical symptoms of hypothyroidism can easily be reversed with thyroid hormone replacement [18]. The relatively high incidence of pericardial effusion due to hypothyroidism and the potential complications of pericardial effusion necessitate early recognition and management [6,8,9,19]. The rarity of the association between these two conditions warrants more research and investigation in order to be well prepared to provide the standard of care.…”

“…Hypothyroidism, having the potential to affect any organ system, can be complicated by serious pathologies requiring timely intervention. One of the rare, yet serious complications of hypothyroidism is pericardial effusion [5][6][7][8][9][10]. Hypothyroidism causes increased permeability of the pericardial capillaries to albumin.This, in addition to decreased drainage of albumin into the lymphatic system, leads to increased colloid pressure within the pericardium and hence, decreased colloid osmotic pressure gradient between the pericardial space and pericardium.…”