12.3 : 頻脈

Tachycardia is the medical term for an increased heart rate. It occurs when the sinus node produces abnormal electrical impulses.

It is caused by irregular heart rhythms called arrhythmias.

Tachycardia in adults is characterized by a pulse rate ranging from 100 to 180 beats per minute.

During tachycardia, the heart might not transport sufficient blood to all regions of the body, leading to decreased oxygen supply to organs and tissues.

While tachycardia might not always present symptoms or complications, untreated tachycardia poses the risk of a stroke and cardiac failure.

In general, the signs and symptoms of tachycardia include palpitations, chest pain, syncope, lightheadedness, rapid pulse rate, and shortness of breath.

Several factors, such as old age, a family history of arrhythmias, and an overactive thyroid gland, may increase the risk of tachycardia.

Additionally, a decrease in blood pressure, an elevated temperature, poor blood oxygenation, exercise, pain, and some medications such as epinephrine can also contribute to tachycardia.