Tachycardia

When you have tachycardia, your heart beats faster than normal for a few seconds to a few hours. Normally, your heart rate is 60 to 100 beats per minute when you’re not active. When your heart beats more than 100 times a minute at rest, that’s tachycardia.

Because your heart beats too often, it doesn’t have the time it needs to fill with blood between beats. This can be dangerous if your heart can’t supply all of your cells with the blood and oxygen they need.

Your heart normally responds to electrical signals from your heart’s sinoatrial (SA) node. These signals control how often your heart beats. When you’ve had a scare or are very emotional or anxious, or are exercising, your heart may send signals more frequently for a short time. This is called sinus tachycardia and goes away when you calm down or rest.

Other types of tachycardia can come back regularly and can be more serious.

Types of supraventricular tachycardia (SVT)

These begin in the atria, or upper chambers of your heart, when you have an issue with electrical signals there.

• Atrial fibrillation.
• Atrial flutter.
• Paroxysmal atrial tachycardia (PAT). Your upper chamber sends out an extra electrical signal that can be too fast.
• Paroxysmal supraventricular tachycardia (PSVT).

Types of ventricular tachycardia

These begin in your ventricles, your heart’s lower chambers, when you have an electrical signal issue in that area.

• Ventricular tachycardia. Ventricles are beating too fast (more than 100 beats a minute).
• Ventricular fibrillation. A problem with your heart’s electrical signals keeps it from pumping the way it should.

Who does tachycardia affect?

Atrial or supraventricular tachycardia can affect:

• Women and people assigned female at birth more than men and people assigned male at birth.
• Children, especially those who have anxiety.
• Anyone who’s very tired or drinks a lot of alcohol or caffeine.
• People who smoke a lot.

Ventricular tachycardia or fibrillation can affect:

• People who’ve had a heart attack, cardiomyopathy (heart muscle issue), myocarditis (inflamed heart muscle), heart failure or heart disease.
• People who smoke or have high blood pressure or diabetes.

How common is tachycardia?

About 2 million Americans have atrial fibrillation and 90,000 others per year get a supraventricular tachycardia diagnosis. Each year, an estimated 184,000 to 450,000 Americans die from ventricular arrhythmias that cause sudden cardiac death.