Supraventricular tachyarrhythmia is a rapid heart rhythm originating above the ventricles, typically involving the atria or atrioventricular node, resulting in a heart rate exceeding 100 beats per minute. It is clinically important because it can cause symptoms such as palpitations, dizziness, or hemodynamic instability, and may require urgent management to prevent complications. A common example is atrial fibrillation, which increases the risk of stroke due to thromboembolism.