heart and blood vessel disorders
Overview of Abnormal Heart Rhythms
Causes of Abnormal Heart Rhythms
The most common cause of arrhythmias is a heart disorder, particularly Overview of Coronary Artery Disease (CAD) , Sometimes no cause for an arrhythmia can be identified. Fast arrhythmias (tachyarrhythmias) may start on their own or be triggered by exercise, emotional stress, excessive alcohol consumption, smoking, or use of drugs that contain stimulants, such as cold and hay fever remedies. An overactive thyroid gland ( Hyperthyroidism ), producing high levels of thyroid hormone, may cause fast arrhythmias. Slow arrhythmias (bradyarrhythmias) may be triggered by pain, hunger, fatigue, digestive disorders (such as diarrhea and vomiting), or swallowing, which can stimulate the vagus nerve excessively. With enough stimulation, which is rare, the vagus nerve can cause the heart to stop for a moment. In most of these circumstances, the arrhythmia tends to resolve on its own. An underactive thyroid gland ( Hypothyroidism ), producing low levels of thyroid hormone, may cause slow arrhythmias. 