The Heart and the Thyroid Gland

Diseases of the thyroid gland can directly alter the normal function of the heart and cause significant complications and personal discomfort. To better understand why this happens, it is helpful to appreciate how the heart works.

The heart itself is called a muscle. It requires oxygen to work and receives oxygen through coronary arteries. If there is disease in these coronary arteries causing a blockage within the lumen and a reduction in coronary artery blood flow, the heart muscle then works with an inadequate oxygen supply and heart pain or “angina” can be produced. Additionally, in order for the heart to beat in a coordinated fashion and expel blood smoothly and efficiently, the heart muscle is stimulated to contract in a synchronized fashion by specialized tissues within the heart which conduct electrical impulses. The impulse normally starts at the top of the right atrium and spreads down through the heart.

When a patient is in a hyperthyroid state, increased levels of thyroxine release from the thyroid gland and stimulate the heart to beat more quickly and more strongly. Initially this may produce a fast heart rate, which is called a tachycardia. In some patients, prolonged stimulation of the heart may cause an irregular heartbeat. Functionally, this is where the electrical impulses form a short circuit within the atria and cause partial or poorly coordinated atrial contractions.

Prolonged and irregular stimulation such as this can cause some increase in blood pressure, which is called systolic hypertension. The diastolic blood pressure, that is the lower of the two blood pressure numbers, is not normally increased. The increased contraction of the heart with increased cardiac output causes a pulse that is easily felt at the wrist and contributes to warm, sweaty hands.

Symptoms and signs of a heart problem for an overactive thyroid gland tend to be the opposite to those mentioned above. They primarily consist of slow heart rate and low blood pressur e. Common symptoms for slow heart rate and low blood pressure in patients include constipation, poor blood flow, and lightheadedness or dizziness upon standing. Prolonged hypothyroidism causes metabolic changes in the body and may produce elevated levels of cholesterol, for example. We are aware of the media attention surrounding some types of elevated cholesterol levels that may produce or aggravate narrowing of the coronary arteries. However, a more exciting area of research now examines the role of blood pressure in regulating cellular nutrition.

Nitric oxide is what the body uses to stimulate your blood vessels to expand and contract, keeping blood pressure in check. Individuals, both men and women, with poor circulation, a history of thyroid or heart disease, including many common symptoms like high blood pressure and elevated cholesterol, are often deficient in the critical molecule nitric oxide. Precursors for the synthesis of nitric oxide include dietary amino acids such as L-arginine, ornithine, and citrulline. The right balance has been shown to stimulate growth hormone for anti-aging benefits, improve insulin sensitivity to help normalize blood sugar, and increase fertility and pleasure sensation by stimulating oxygenation and blood flow.

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For more information about my clinic in Oradell, NJ, including Functional Medicine, Neurology & Nutrition, and The Grassroots Medicine Initiative, please call (201) 261-5430.