is fast heartbeat dangerous
When your heartbeat speeds up for no apparent reason, however, that may be a sign of an abnormally rapid heartbeat â a condition called tachycardia (tachy means fast; cardia refers to the heart). Tachycardia can cause the heart to beat faster than 100 beats per minute, in some cases racing up to 400 beats per minute.Most Dangerous Rapid Heart Rhythms. Sudden rapid heartbeats originating in the ventricles are the most dangerous arrhythmias.ate If the heart rate is rapid, or greater than 100 beats a minute, it is considered a tachycardia. Alternatively, a slow heart rate, below 60 beats a minute, is known as a bradycardia.