Definition

Ventricular tachycardia is a very fast heart rate. It beats at a rate greater than 100 beats per minute. When the heart is moving this fast it is not able to properly fill with blood. It will decrease the amount of blood the heart pushes out to the body. If the rapid heart rate continues it can lead to low blood pressure, heart failure, and death.

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Causes

The signal for a heart beat normally comes from the SA node. Ventricular tachycardia happens when areas in the lower part of the heart send abnormal signals. The extra beats cause the very fast heart rate.

The abnormal signals are caused by damage to the heart muscle. The damage may be due to conditions like a heart attack or cardiomyopathy.

Risk Factors

Factors that may increase your risk of ventricular tachycardia include:

• Coronary artery disease (CAD)
• History of heart attacks
• Heart problems, such as cardiomyopathy, mitral valve prolapse, valvular heart disease, or ion channel disorders
• Sarcoidosis
• Use of certain medications, such as antipsychotics or anti-arrhythmic drugs
• Extreme physical or emotional overstimulation
• Low oxygen levels in the blood
• Very high levels of acid in the body
• Drinking alcohol often
• Stimulants, such as caffeine or cocaine

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Symptoms

Ventricular tachycardia may cause:

• A sensation of the heart beating very rapidly—palpitations
• Feeling lightheaded
• Feeling short of breath
• Fainting
• Chest discomfort
• Pale skin color

Diagnosis

Ventricular tachycardia is often an emergency. Heart problems will be suspected based on symptoms. An ECG will show the electrical activity of the heart. It will show tachycardia.

Other tests may be done to see what may trigger tachycardia:

• Exercise stress test to test the heart under physical stress
• Electrophysiology test to study the electrical signals of the heart

Treatment

Emergency care can help to improve blood flow. CPR may be needed to improve blood flow until further care is given. A defibrillator may help to shock the heart back into a normal rhythm again.

Treatment to stop the tachycardia may include:

• Medicine to keep a normal heart rhythm
• Procedures such as catheter ablation—destroys tissue that is making abnormal signals
• Surgeries such as open heart surgery—make changes to stop abnormal signals

An automatic defibrillator may be needed of other treatment does not work. The device will deliver shocks to the heart when needed to keep the heart rate steady. It is implanted just under the skin.

Prevention

Steps that may prevent some ventricular tachycardia include:

• Proper treatment for any underlying heart problems. Medicine to control heart rate and blood pressure if needed.
• Moderate or no use of alcohol and caffeine.
• Maintain a healthy weight and exercise often.
• Quit smoking.