a condition that makes your heartbeat more than 100 times per minute. There are three kinds of it. Heavy exercise, fever, fear, stress, anxiety, some medications, and drugs can lead to tachycardia. More triggers are anemia, overactive thyroid, and any destruction from having a heart attack or heart failure.  Some symptoms of Tachycardia are dizziness, lightheadedness, shortness of breath, chest pain and heart palpitations. In intense cases it could cause you to become unconscious or go into cardiac arrest. There are some case where a super-fast heart rate has no symptoms at all.

the most common way used to diagnose tachycardia is electrocardiogram, most commonly called an ECG or EKG. This test does not heart and it records your heart's electrical activity using small sensors on your chest and arms. A fast heartbeat may fix itself. Sometimes people can slow their heart rate using basic physical movements. However, some need vagal maneuvers, medications and cardioversion to treat tachycardia.

For adults, any heart rate of 100 beats or more is considered to be too fast.  As of April 27, 2018, 3,994 Americans were on a waiting list for heart transplant, and 55 were waiting for heart and lung transplant. In 2017, emergency medical services looked at-assessed cardiac arrest that happened outside of the hospital and an estimated 356,461 people, emergency services treatment was started in 52%. The beginning tracked cardiac rhythm was ventricular fibrillation, ventricular tachycardia, or shockable by automated external defibrillator in only 18.7%. Adult survival to hospital discharge was 10.4% and only 8.4% had a good function status when discharged.

https://www.webmd.com/heart-disease/atrial-fibrillation/what-are-the-types-of-tachycardia

 https://www.mayoclinic.org/diseases-conditions/tachycardia/diagnosis-treatment/drc-20355133

https://www.heart.org/en/health-topics/arrhythmia/about-arrhythmia/tachycardia--fast-heart-rate

https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2019/02/15/14/39/aha-2019-heart-disease-and-stroke-statistics