Imbalance in thyroid levels can lead to various ailments. Medical science is evolving by each passing day – making it possible to acquire knowledge of the human body and of the multiple disorders that can affect it. Now, it has been found that high levels of thyroid can lead to an irregular heartbeat. The Journal Circulation has published this report, and this is yet another compelling reason for why a person should opt for a thyroid test on an yearly basis. The higher the thyroid hormones are in the blood, the higher the risk is for developing this condition. In the medical world, this condition is called the atrial fibrillation.