The thyroid is an endocrine gland that plays a very important role for the proper growth, development and proper functioning of all the systems of the human body, mainly through the secretion of thyroid hormones T3 and T4. The thyroid gland has a direct effect on heart function. Thyroid hormones increase the body’s metabolism, heat production and cardiac work to meet the body’s increased needs.
The hyperfunction of the thyroid gland is called hyperthyroidism, and is accompanied by tachycardia even at rest. The patient may experience various arrhythmias while 10% of hyperthyroid patients have atrial fibrillation. Hyperthyroidism lowers diastolic blood pressure, increases pulse width, increases cardiac output, and can lead to increased pressure in the pulmonary artery (pulmonary hypertension). Essentially it is a form of continuous stress test for the heart, which if it already has an underlying disease, it will immediately manifest as heart failure.
Hypothyroidism, on the other hand, can also affect the heart. It can raise blood pressure and cholesterol to unimaginable heights, cause fluid to collect in the pericardium, and lead to the occurrence of almost all cardiac arrhythmias.
It goes without saying that anyone suffering from a thyroid condition should regularly check their hormones with their doctor and in case of over- or under-functioning they will need cardiological advice.
