👉 A brachycardia is a irregular heart rhythm, which occurs when there is a rapid heartbeat or abnormal beating of the heart. This type of heart rhythm can occur at any time during the day, and it can be caused by stress, illness, medications, or certain conditions such as heart failure or atrial fibrillation. A brachycardia can cause symptoms including shortness of breath, dizziness, lightheadedness, nausea, and pain in the chest or back
