Ventricular tachycardia

00:00 / 00:00



Ventricular tachycardia


Cardiac tumors

Cardiac tumors




Ventricular tachycardia


0 / 13 complete

USMLE® Step 1 questions

0 / 2 complete

High Yield Notes

9 pages


Ventricular tachycardia

of complete


USMLE® Step 1 style questions USMLE

of complete

A 24-year-old male presents to the emergency department after a witnessed syncopal episode. The patient’s parents report they had just finished dinner when their son spontaneously passed out. The patient does not recall the event and had no prodromal features. He is otherwise healthy and does not take any medications, use alcohol, tobacco, or illicit substances. Vital signs are within normal limits, and physical examination is unremarkable. Electrocardiogram is demonstrated below:

Image reproduced from Wikimedia Commons  

If left untreated this patient is at risk for which of the following complications?  

External References

First Aid



Content Reviewers

Ventricular refers to the bottom chambers of the heart, the right and left ventricles, as opposed to the top chambers, the right and left atria. Tachycardia refers to a fast heart rate. Typically, a tachycardic, or fast, heart rate is considered anything above 100 beats per minute, or bpm. However, ventricular tachycardia is different than a fast heart rate from exercising, which is called sinus tachycardia.

Normally, the electrical signals that generate each heartbeat start in the right atrium at the sinus node, which is also known as the sinoatrial node, or the SA node. If the rate goes over 100 bpm and originates in the SA node, it’s considered sinus tachycardia, which is totally normal.

However, heartbeats can become abnormal if the electrical signals don’t start in the SA node, but start in the ventricles instead. Premature Ventricular Contractions, or PVCs, are single beats originating from the lower chambers. Any time there are more than three beats like this in a row, then it’s defined as ventricular tachycardia. Ventricular tachycardia, sometimes called V-tach, or VT, can cause the heart rate to rise above 100 beats per minute, which can be extremely dangerous and lead to sudden cardiac death.

Hold on, how can that happen? It’s not like while we exercise we’re risking sudden cardiac death, right? Well, even though we say tachycardia is anything above 100 beats per minute, most patients with ventricular tachycardia experience heart rates as high as 250 beats per minute. 250 beats per minute mean that the heart is beating over four times per second. When the chambers are pumping that fast, they don’t have enough time to even fill with blood, so the heart is furiously pumping out only tablespoons of blood to your body, and most importantly, to your brain, which is just not enough. If this happens, a person can have symptoms from not having enough perfusion to their tissues, such as chest pain, fainting, dizziness, or shortness of breath. It can even cause sudden death.


Ventricular tachycardia is a type of tachycardia, or a rapid heartbeat that arises from improper electrical activity of the heart presenting as a rapid heart rhythm that starts in the ventricles. There are two main types of ventricular tachycardia: monomorphic, and polymorphic ventricular tachycardias.

In monomorphic ventricular tachycardia, all the beats look the same because the impulse is either being generated from increased automaticity of a single point in either the left or the right ventricle, or due to a reentry circuit within the ventricle. Polymorphic ventricular tachycardia, on the other hand, is most commonly caused by abnormalities of ventricular muscle repolarization. Ventricular tachycardia is a potentially life-threatening arrhythmia because it can cause low blood pressure and may lead to ventricular fibrillation, asystole, and sudden death. Ventricular tachycardia ranges between 100 and 250 bpm.


Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.