It is normal for the heart to beat faster with exercise or stress. However, some fast heart beats are abnormal. They are called arrhythmias. Some arrhythmias can be life-threatening. They need to be treated.

Electrical System and Chambers of the Heart

Causes

Signals in the heart control how the heart beats. Tachycardia is caused by abnormal signals.

Risk Factors

Things that raise the risk of tachycardia are:

Heart problems, such as:
- A prior heart attack
- Cardiomyopathy—heart muscle disease
- Myocardial ischemia—poor blood flow to the heart
Electrolyte problems—too much or too little calcium, sodium, magnesium, and potassium in the blood
Hypoxemia—not enough oxygen in the blood
Acidosis—too much acid in the body’s fluids

Symptoms

Symptoms of tachycardia are:

Pounding heartbeats
Fast heartbeats
Lightheadedness or fainting
Chest pain
Problems breathing

Diagnosis

Your doctor will ask about symptoms and past health. A physical exam will be done.

Tachycardia is usually diagnosed with an electrocardiogram (ECG). Patches are placed on the chest, arms, and legs—to check heart activity.

Other tests may be:

Holter monitor—a device worn to measure heart activity over 24 to 48 hours
Exercise test—to see if symptoms happen during physical activity
Electrophysiology study—wires placed inside the heart to see where the abnormal rhythm starts
Cardiac catheterization—a tube put through a blood vessel to check blood flow to the heart

Treatment

The goal is to slow the fast heartbeats and prevent them from happening again. This includes treating any conditions that are causing the fast heartbeats.

Fast heartbeats that are life-threatening need care right away.

Care options may be:

Medicines to:
- Slow the heartbeats
- Prevent blood clots
- Lower blood pressure
- Treat other underlying conditions
Ablation—destroying some heart tissue with cold or heat, to block abnormal signals
Cardioversion—an electric shock to reset the heart, which is used for:
- Life-threatening rhythms—ventricular tachycardia or ventricular fibrillation
- Milder rhythm problems such as atrial fibrillation
An implantable cardiac device (ICD)—put under the skin to check heart activity and shock abnormal rhythms

Device to Correct Tachycardia

Prevention

The risk of tachycardia may be lowered by:

A healthful diet, daily exercise, and not smoking
Maintaining a healthy weight
Avoiding or limiting caffeine and alcohol
Managing stress
Getting regular physical exams
Treating health problems, such as high blood pressure or high cholesterol

RESOURCES:

American Heart Association
http://www.heart.org/

Heart Rhythm Society
http://www.hrsonline.org/

CANADIAN RESOURCES:

Canadian Heart Rhythm Society
http://www.chrsonline.ca

Heart and Stroke Foundation of Canada
http://www.heartandstroke.ca

References:

Arrhythmias. American Heart Association website. Available at: https://www.heart.org/en/health-topics/arrhythmia. Accessed September 10, 2021.

Cardioversion of atrial fibrillation. EBSCO DynaMed website. Available at: https://www.dynamed.com/procedure/cardioversion-of-atrial-fibrillation. Accessed September 10, 2021.

Implantable cardioverter defibrillator (ICD). EBSCO DynaMed website. Available at: https://www.dynamed.com/device/implantable-cardioverter-defibrillator-icd-16. Accessed September 10, 2021.

Littmann L, Olson EG, et al. Initial evaluation and management of wide-complex tachycardia: a simplified and practical approach. Am J Emerg Med. 2019;37(7):1340-1345.

Risk factors & prevention. Heart Rhythm Society website. Available at: https://upbeat.org/early-warning-signs#axzz3NOr35s6f. Accessed September 10, 2021.

Supraventricular tachycardia (SVT). EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/supraventricular-tachycardia-svt. Accessed September 10, 2021.

Tachyarryhthmias. EBSCO DynaMed website. Available at: https://www.dynamed.com/approach-to/tachyarrhythmias-approach-to-the-patient. Accessed September 10, 2021.

Ventricular tachycardia—approach to the patient. EBSCO DynaMed website. Available at: https://www.dynamed.com/approach-to/ventricular-tachycardia-approach-to-the-patient. Accessed September 10, 2021.

Last reviewed July 2021 by EBSCO Medical Review Board Nicole Meregian, PA
Last Updated: 9/10/2021

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