Fast Heart Rate Causes: When to Go to the ER

Medically Reviewed By Meredith Goodwin, MD, FAAFP
Was this helpful?

Seek emergency medical attention if you experience a fast heart rate alongside symptoms like chest pain, difficulty breathing, and fainting. Doctors may consider a heart rate to be fast if it is over 100 beats per minute in most adults.

However, your heart may beat faster for a range of different factors, not all of which are dangerous. For example, you may temporarily experience a faster heart rate due to fever, pregnancy, or anxiety.

A fast heart rate that is long lasting may be a sign of an underlying condition.

Read on to learn more about when and why a fast heart rate can be dangerous. This article also covers what you can do about it.

Signs you need emergency fast heart rate treatment

an older man is at an outdoor gym holding his chest
YorVen/Getty Images

Unless you also have a history of heart problems or conditions such as atrial fibrillation (AFib), brief episodes of fast heart rate — such as palpitations that only last for a second or two — are not usually a cause for concern. It is still important to discuss them with your doctor, but you likely do not need to rush to the emergency room.

However, if you have symptoms that include the following, seek emergency help by calling 911:

Fast heart rate causes

Fast heart rate, or tachycardia, is defined as a heart beating more than 100 times per minute. Sometimes, a fast heart rate is regular. Other times, the beat is erratic. This is known as arrhythmia

A fast heart rate can occur briefly or continue for a longer period of time. You may not even know that you have a fast heart rate unless you are examined by a healthcare professional. You may or may not have other symptoms alongside a fast heart rate.

Lifestyle-related causes

Some factors that can cause a fast heart rate include:

  • anxiety
  • exercise
  • stress
  • pain
  • stimulants, such as caffeine

Sometimes, eating certain foods or overeating can bring on a fast heart rate. This is because eating causes blood to redirect to your digestive system, which can raise both your heart rate and blood pressure.

Usually, a fast heart rate after eating is not a cause for concern. However, it is important to mention its occurrence to your doctor, especially if it happens repeatedly.

Underlying conditions

According to one 2019 study, a higher heart rate may occur alongside certain health conditions, such as:

Types of fast heart rate

Fast heart rates can occur in different parts of your heart. Doctors classify different types of fast heart rate related to the location in which they occur. These include:

  • AFib: This rapid, irregular heartbeat happens due to irregular electrical impulses in the atria, which are the upper chambers of your heart. AFib is the most common type of tachycardia.
  • Atrial flutter: This rapid, regular heartbeat sometimes presents after an episode of AFib.
  • Sinus tachycardia: This occurs when your body responds to stimuli such as exercise or emotional distress with a normal increase in heart rate. 
  • Supraventricular tachycardia: This fast heart rate starts above the lower chambers of the heart.
  • Ventricular tachycardia (VT): This rapid heart rate happens because of abnormal electrical signals in the lower chambers of the heart, or the ventricles. Episodes of VT that last for longer than a few seconds can be life threatening.
  • Ventricular fibrillation: This fast rate occurs when rapid, irregular electrical impulses cause the lower chambers of your heart to quiver instead of pump blood to your body. This type can be fatal and may require an electric shock to restore your heart to a healthy rhythm.


Potential severe complications of fast heart rates depend on which type of tachycardia you have, how fast your heart is beating, how long your rapid heart rate lasts, and whether or not you have other heart conditions

Some of the more serious complications include:

Treatment for a fast heart rate

The treatment you receive will depend on your symptoms and the type of heart condition you have. 

Emergency treatment

If you have ventricular tachycardia along with other symptoms that indicate that your body is in distress, such as difficulty breathing and chest pain, your emergency treatment can involve:


A healthcare professional may recommend medications to slow your heart rate and prevent further episodes of rapid heart rate. These medications may include antiarrhythmic drugs such as:

  • amiodarone
  • sotalol
  • dofetilide


Sometimes, surgical procedures may be necessary to treat a fast heart rate. These include:

  • Radiofrequency ablation: This procedure destroys the heart tissue causing abnormal beats. Doctors may use it to treat certain conditions that are causing a fast heart rate, such as AFib.
  • Implantation of a cardioverter-defibrillator: Doctors may implant a device that detects life threatening rapid heart rates and automatically sends an electric shock to the heart to restore normal rhythm. This device is especially useful for people with ventricular tachycardia or AFib.

Lifestyle changes

If you have a high resting heart rate, your doctor may recommend making certain lifestyle changes. These can have a significant impact on lowering your resting heart rate.

For example, you could try exercising more where possible. Increased fitness can improve your overall physical conditioning and result in a lower resting heart rate.

However, if your high heart rate is happening due to an underlying condition, exercise may trigger or worsen the condition. So, always discuss lifestyle changes with a doctor first.

Doctors may also suggest making certain dietary changes, including:

  • limiting possible triggers, such as caffeine or alcohol
  • trying certain supplements, such as alpha-lipoic acid, with a doctor’s supervision
  • consuming a cardiac diet to help promote overall heart health, making sure to include:

If you have concerns about your heart rate, discuss these with your physician to see what steps you could take for better heart health.


If you experience a fast heart rate alongside symptoms such as fainting, chest pain, or difficulty breathing, you need emergency medical attention.

If you feel concerned about having a fast heart rate, contact your doctor. They can help rule out underlying causes.

Experiencing a fast heart rate can be alarming. Some people may notice heart palpitations or a pounding in their chest, while others may not experience any symptoms at all.

A fast heart rate can result from certain lifestyle factors, like consuming a lot of caffeine or experiencing stress. Or it could signify an underlying condition, such as arrhythmia or AFib.

Was this helpful?
Medical Reviewer: Meredith Goodwin, MD, FAAFP
Last Review Date: 2022 Jan 27
View All Heart Health Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.