Tachycardia: Fast Heart Rate

The normal average resting heart rate is 60-100 beats per minute. Tachycardia is when the heart beats too fast when at rest — at a rate of more than 100 beats per minute. This can depend on age, health status and physical condition. Learn about the types of tachycardias:

• Supraventricular tachycardia (SVT)/ Paroxysmal supraventricular tachycardia (PSVT)
• Sinus tachycardia
• Ventricular tachycardia

EKG strip showing a normal heartbeat

EKG strip showing tachycardia

Supraventricular tachycardia (SVT)/ Paroxysmal supraventricular tachycardia (PSVT)

SVT is a fast heart rate, greater than 100 beats per minute, that starts in the atria, the heart’s upper chambers. The electrical signals occur abnormally and speed up the heart rate. The rapidly beating heart prevents the heart chambers from filling completely between contractions (beats). This may decrease blood flow to the body.

SVT is the most common abnormal heart rhythm in infants and children. Paroxysmal SVT means that the abnormal rhythm may come and go over minutes or days.

View an animation of tachycardia.

What are the risk factors for SVT/PSVT?

• Anxiety and stress
• Increasing age – people middle-aged and older
• Sex – women more than men
• Children (SVT is the most common abnormal heart rhythm in children)

For some people, SVT/PSVT is caused by exercise, stress or lack of sleep, while others do not notice anything at all.

Issues that may cause an SVT episode include:

• Age
• Anemia
• Heart disease
• Dehydration
• Coronary artery disease; having had heart surgery or other heart problems
• Congenital heart disease
• Other heart conditions, such as Wolff-Parkinson-White syndrome
• Chronic lung disease
• Excessive caffeine intake
• Excessive alcohol intake
• Smoking or other tobacco products
• Drug misuse, including cocaine and methamphetamines
• Pregnancy
• Menopause
• High blood pressure
• Certain over-the-counter medications, including those for asthma, colds and allergies

What are the symptoms of SVT/PSVT?

• Very fast (rapid) heartbeat that may come and go
• A fluttering or pounding in the chest (palpitations)
• A bounding pulse feeling in the neck
• Weakness or feeling very tired (fatigue)
• Chest discomfort
• Shortness of breath
• Lightheadedness or dizziness
• Sweating
• Fainting (syncope) or near fainting
• Nausea 

How is SVT/PSVT diagnosed?

SVT
Your health care professional will ask you for a detailed medical history (including potential causes) and a list of symptoms. Then you will be advised to get an electrocardiogram (EKG).

PSVT
Because PSVT is “paroxysmal” (occasional and sudden), an EKG taken during an appointment may look normal. To “catch” an episode, your health care professional may suggest a portable heart monitor (Holter monitor or event monitor) to wear at home that will record your heart rhythm over time.

How is SVT/PSVT treated?

Most people with SVT/PSVT don't need treatment. However, an episode may be stopped with one of these methods, under the supervision of a health care professional. These affect the vagus nerve, which helps control the heartbeat.

• Carotid sinus massage: Gentle pressure is applied on the neck where the carotid artery splits into two branches.
• Vagal maneuvers: Simple moves such as coughing or holding your nostrils closed while attempting to blow air through your nose.
• Dive reflex: This is the response by the body to plunging your face in ice-cold water. This is called a vagal maneuver. It should be done only with a health care professional’s instruction.

Other treatments as needed:

• Medications: If you have frequent episodes of SVT, you may be prescribed medication to control your heart rate or restore a normal heart rhythm.
• Cardioversion: This procedure delivers a shock to the heart, through patches or paddles, to restore the normal heart rhythm.
• Catheter ablation: Thin, flexible tubes called catheters are inserted through the veins or arteries, usually in the groin. Sensors on the tip of the catheter use heat or cold energy to create tiny scars in the heart to block irregular electrical signals. This restores a normal heartbeat.