Heart Healthy : Understanding Your Cardiovascular SystemShare:FacebookPinterestTwitterMailWhat is the medical term for a dangerously fast heartbeat?13%Next Correct Incorrect Tachycardia is a heart rate over 100 beats per minute, which can be risky if sustained. What is the medical term for a dangerously fast heartbeat? Tachycardia Bradycardia Normal Rhythm Arrhythmia 13%