What is the Origin of Thyroid and Heart?

This association has been a recognized clinical entity for centuries, with descriptions of rapid heart rate and palpitations linked to goiter dating back to the 17th century. The formal endocrine understanding of this axis emerged with the isolation and characterization of thyroid hormones, Thyroxine (T4) and Triiodothyronine (T3), and the subsequent identification of their receptors in myocardial tissue. This established a molecular basis for the observed clinical symptoms.

What is the Mechanism of Thyroid and Heart?

The mechanism is primarily mediated by the active hormone, T3, which acts through nuclear thyroid hormone receptors (TR-alpha and TR-beta) present in cardiac muscle cells and vascular smooth muscle. T3 binding upregulates the expression of genes that control the heart's pumping efficiency, such as the sarcoendoplasmic reticulum calcium transport ATPase (SERCA). This action increases the speed and force of systolic contraction, accelerates diastolic relaxation, and modulates systemic vascular resistance, thereby controlling overall cardiac output.

Thyroid and Heart ∞ Area

Thyroid and Heart

Meaning

Thyroid and Heart describes the profound and intimate physiological connection between the thyroid gland’s hormones and the function of the cardiovascular system. Thyroid hormones are essential regulators of cardiac contractility, heart rate, and systemic vascular resistance. Dysregulation in thyroid function, whether hyperthyroidism or hypothyroidism, leads to predictable and clinically significant alterations in cardiac dynamics and performance. This link underscores the systemic nature of endocrine health.