What is the term for a rapid heart rate over 100 beats per minute?

A rapid heart rate over 100 beats per minute is called tachycardia.

In adults, the term generally refers to a resting heart rate above 100 beats per minute. Tachycardia is a description of rate, not a single disease. It can be sinus tachycardia, in which the heart’s normal pacemaker is driving faster, or an arrhythmia caused by abnormal electrical activity elsewhere in the heart.

Exercise, fever, pain, anxiety, dehydration, anemia, and some medicines can produce an appropriate faster rate. Other cases arise from disorders such as supraventricular tachycardia or ventricular tachycardia. The clinical meaning depends on the rhythm, duration, symptoms, and underlying cause.

Hypertension means high blood pressure, not a fast pulse. Bradycardia is the opposite rate pattern, generally a slow heart rate. Arrhythmia is a broader term for an abnormal rhythm and can include tachycardia, but it is not the single canonical answer to a question defining a rapid rate above the adult resting threshold.