PMID: 8597489Jan 1, 1995Paper

Heart and thyroid

Annales d'endocrinologie
M KleinJ Leclére

Abstract

Thyroid hormones may exert cardiovascular actions by direct effects on the myocardium, by interacting with the sympathetic nervous system and through alterations of the peripheral circulation. Then, thyroid hormones increase myocardial contractility and relaxation, sensitise the myocardium to sympathetic nervous system and decrease arterial resistance. Hyperthyroidism results in an enhanced myocardial contractility, an increased cardiac output and a fall in systemic vascular resistance. Nevertheless "high output" cardiac decompensation may occur. Thyrotoxicosis may trigger arrythmia and disease seems to be associated with an increase in the frequency of mitral valve prolapse. Even in mild or subclinical hyperthyroidism complication may occur. Sympathetic blocking agents are the treatment of choice in addition to aetiologic treatment. Hypothyroidism is associated with bradycardia, a decreased cardiac output, increased vascular resistance and perhaps a decreased sensitivity of the sympathoadrenal system. An increase in cholesterolemia leads to an additional risk for the development of atherosclerosis. Main cardiovascular complications of hypothyroidism are angina pectoris, diastolic hypertension, atrio-ventricular blocks or peric...Continue Reading

Related Concepts

Related Feeds

Bradyarrhythmias

Bradyarrhythmias are slow heart rates. Symptoms may include syncope, dizziness, fatigure, shortness of breath, and chest pains. Find the latest research on bradyarrhythmias here.

Cardiomyopathy

Cardiomyopathy is a disease of the heart muscle, that can lead to muscular or electrical dysfunction of the heart. It is often an irreversible disease that is associated with a poor prognosis. There are different causes and classifications of cardiomyopathies. Here are the latest discoveries pertaining to this disease.

Arrhythmia

Arrhythmias are abnormalities in heart rhythms, which can be either too fast or too slow. They can result from abnormalities of the initiation of an impulse or impulse conduction or a combination of both. Here is the latest research on arrhythmias.

Cardiovascular Disease Pathophysiology

Cardiovascular disease involves several different processes that contribute to the pathological mechanism, including hyperglycemia, inflammation, atherosclerosis, hypertension and more. Vasculature stability plays a critical role in the development of the disease. Discover the latest research on cardiovascular disease pathophysiology here.

Atrial Fibrillation

Atrial fibrillation is a common arrhythmia that is associated with substantial morbidity and mortality, particularly due to stroke and thromboembolism. Here is the latest research.