If the person experience an irregular heartbeat, in medical term, it called cardiac arrhythmia, it is the condition in which the heart's normal rhythm is disrupted. The most common type of irregular heartbeat due to a hyperthyroid condition is Atrial Fibrillation (AF or A-fib). Atrial Fibrillation may cause no symptoms but it is often associated with palpitations, fainting, chest pain, or congestive heart failure. However, in some people AF is caused by otherwise idiopathic or benign conditions. AF increases the risk of stroke the degree of stroke risk can be up to seven times that of the average population, depending on the presence of additional risk factors such as high blood pressure. It may be identified clinically when taking a pulse and the presence of AF can be confirmed with an Electrocardiogram (ECG) which demonstrates the absence of P waves together with an irregular ventricular rate. When given medications the heart rate can be controlled but the irregular beats remain.
In hyperthyroid condition, the heart becomes stimulated by excessive thyroid hormone secretion, often the first sign that a person may be suffering from hyperthyroidism. Hyperthyroidism is a condition in which the thyroid gland makes too much thyroid hormone. Some people complain of palpitations or a conscious feeling of an irregularity in the beating of the heart. When the hyperthyroid condition becomes symptomatic, the term thyrotoxicosis is applied. When the heart is affected by thyrotoxicosis, it is called thyrotoxic heart disease.
If the heartbeat is fast, but no irregular, a beta blocker tablet will best help. Treatment can be based on the physical exam and ECG findings. If the AF is just acute (new) at onset, there is a big possibility that the heartbeat will revert to normal rhythm after the correction of the hyperthyroid condition. On the other hand, chronic or long-standing AF may remain to be permanent even after thyroid treatment.
Aside from the treatment described above, thyrotoxicosis should also be controlled by medications that will suppress the thyroid hormone production. After a few weeks of treatment, the thyroid hormone levels should be rechecked. If it has normalized, then either a surgical removal of the thyroid or radioactive iodine treatment should be considered, to permanently control the overactive thyroid glands. Find an endocrinologist who can do the radioactive treatment. The surgical removal of the thyroid is preferred when there is an accompanying thyroid enlargement. After the removal of the thyroid, the thyroid hormone should be regularly monitored since a hypothyroid condition can be a postoperative or post radioactive sequel of the treatment.