Thyroid Disease and the Heart

Abstract

Abstract-The cardiovascular signs and symptoms of thyroid disease are some of the most profound and clinically relevant findings that accompany both hyperthyroidism and hypothyroidism. On the basis of the understanding of the cellular mechanisms of thyroid hormone action on the heart and cardiovascular system, it is possible to explain the changes in cardiac output, cardiac contractility, blood pressure, vascular resistance, and rhythm disturbances that result from thyroid dysfunction. The importance of the recognition of the effects of thyroid disease on the heart also derives from the observation that restoration of normal thyroid function most often reverses the abnormal cardiovascular hemodynamics. In the present review, we discuss the appropriate thyroid function tests to establish a suspected diagnosis as well as the treatment modalities necessary to restore patients to a euthyroid state. We also review the alterations in thyroid hormone metabolism that accompany chronic congestive heart failure and the approach to the management of patients with amiodarone-induced alterations in thyroid function tests.

High‐Normal Thyroid‐Stimulating Hormone Shows a Potential Causal Association With Arrhythmia Recurrence After Catheter Ablation of Atrial Fibrillation

“…Therefore, when cardiovascular disease is present, clinicians usually determine whether thyroid disorders are concomitantly present in individuals. In particular, hyperthyroidism, either overt or subclinical, is known to carry a risk of atrial fibrillation (AF), often inducing heart failure 1, 2, 3…”

Sudden cardiac arrest as a rare presentation of myxedema coma: case report

“…Cardiovascular manifestations which are frequently seen in hypothyroid state include decrease in cardiac output, heart rate, stroke volume, and myocardial contractility and an increase in systemic vascular resistance. Although the most common cardiac arrhythmias seen in hypothyroidism are sinus bradycardia, low voltage QRS complexes and prolongation of QT interval, ventricular tachycardia, torsades de pointes, and ventricular fibrillation have been reported in a few cases [1]. Sudden cardiac arrest (SCA) is uncommon in profound hypothyroidism.…”

“…Thyroid hormone affects the action potential duration and repolarization currents in cardiac myocytes through both genomic and non-genomic mechanisms [1,3]. The pacemaker regulated genes, hyperpolarization activated cyclic nucleotide-gated channels 2 and 4, are transcriptionally regulated by thyroid hormone [4].…”

Acute cardiac decompensation in a patient with beta‐thalassemia and diabetes mellitus following cessation of chelation therapy

“…Hypothyroidism may have an adverse chronotropic and inotropic effect on the heart 33. If hypothyroidism is diagnosed early, intensification of chelation therapy may improve thyroid function even without thyroid hormone replacement 34.…”