A heart rhythm disorder in which the heart beats 100 or more times a minute. Can be life-threatening if it lasts more than a few seconds.

Ventricular tachycardia, also called V-tach, is caused by incorrect heart signaling. The lower heart chambers beat too fast. A previous heart attack and some heart diseases may cause it. So can some medicines, stimulants like cocaine, and changes in body minerals like potassium. V-tach that lasts more than 30 seconds is a medical emergency.

Symptoms include chest pain, pounding heartbeat, fainting, dizziness, and shortness of breath. Get emergency help for new or unusual chest pain. V-tach can be a medical emergency even if symptoms are mild.

Treatment includes medicines and a procedure or device to control or reset the heartbeat. Sometimes, open-heart surgery is needed.