How much is too fast?

Heart rate over 100 beats/min is too fast.

Heart rate is the number of beats per minute of the human heart, one of the basic vital signs of a person, easily affected by mood swings, exercise, drinking, etc., usually measured in a quiet state. Adults in quiet, awake conditions normal heart rate range of 60-100 beats/min, so heart rate over 100 beats/min is too fast, generally referred to as tachycardia. Tachycardia may be related to physiological factors such as strenuous exercise, emotional excitement and shock, and may also be related to pathological factors such as arrhythmia, cardiomyopathy and heart failure. Clinical manifestations are palpitations, dizziness and amaurosis.