What Is Tachycardia?
Tachycardia is a condition that makes your heart beat faster than normal. Your faster heart rate might last for a few minutes or a few hours.
When you're not moving around, your heart should beat between 60 and 100 times per minute. Your heart rate can go up when you're exercising or under stress, and that's not necessarily a concern. If your heartbeat is more than 100 per minute when you're at rest, that can cause problems.
If your heart is beating more than 100 times per minute, it might not be able to fill up with blood between beats. As a result, your cells might not get all the blood and oxygen they need to function.
There are different types of tachycardia, with different causes.
Types of Tachycardia
Tachycardia is divided into three types.
Supraventricular tachycardia
This happens when the electrical signals in the heart's upper chambers misfire and cause the heart rate to speed up. It beats so fast that it can't fill with blood before it contracts. There are different types of supraventricular tachycardia:
- Atrial fibrillation, in which your upper chambers move irregularly and out of rhythm with the lower chambers
- Atrial flutter, in which your upper chambers maintain a regular beat, but it's fast and out of rhythm with the lower chambers
- Paroxysmal atrial tachycardia (PAT), in which your upper chambers send out an extra electrical signal
- Paroxysmal supraventricular tachycardia (PSVT), in which the electrical signals repeat. That can cause a fast heartbeat that starts and stops suddenly
Ventricular tachycardia
This is a rapid heart rate that starts in your heart's lower chambers. It happens when the electrical signals in these chambers fire the wrong way. There are two types:
- Ventricular tachycardia means the ventricles are beating too fast
- Ventricular fibrillation is a problem with the electrical signals
Sinus tachycardia
This happens when your heart's natural pacemaker sends out electrical signals faster than normal. Your ticker beats fast, but it beats the way it should.
What is inappropriate sinus tachycardia?
Your heart's pacemaker sometimes has a good reason to send out faster-than-normal signals. This might happen because you're exercising, under stress, or have a fever. When there's no reason for the faster signals, that's called inappropriate sinus tachycardia.
What Causes Tachycardia?
Tachycardia has many causes.
Supraventricular tachycardia. This type is most likely to affect people who smoke, drink too much alcohol, or have a lot of caffeine. In some cases, it's linked to heart attacks. It's more common in women and children.
Ventricular tachycardia. The ventricular type is associated with abnormal electrical pathways that are present at birth (long QT), structural problems of the heart (such as cardiomyopathy or coronary disease), medications, or electrolyte imbalance. Sometimes, the reason is unclear.
Sinus tachycardia. Strenuous exercise, a fever, fear, stress, anxiety, certain medications, and street drugs can lead to this type. It also can be triggered by anemia, an overactive thyroid, or damage from a heart attack or heart failure.
Can pregnancy cause tachycardia?
Tachycardia during pregnancy is common. When you're pregnant, your body experiences all kinds of changes, including some that are heart-related. Doctors have long used the guideline that pregnancy can increase your resting heart rate 10 to 20 beats per minute. If your heartbeat is elevated during pregnancy, your doctor may want to conduct tests. Those might include blood tests, or an EKG. You may not need any treatment at all.
Tachycardia Symptoms
No matter which type of tachycardia you have, you may feel:
- Dizziness
- Lightheadedness
- Shortness of breath
- Chest pain
- Heart palpitations, a flopping feeling in your chest
In extreme cases, you could become unconscious or go into cardiac arrest.
But sometimes, a superfast heart rate causes no symptoms at all.
Does tachycardia cause high blood pressure?
Several studies have found that a faster heartbeat is linked to high blood pressure, though the cause-and-effect relationship isn't clear.
Tachycardia Diagnosis
To find out whether you have tachycardia, your doctor may order different kinds of tests. They include:
Electrocardiogram (EKG). This records the electrical activity in your heart and helps your doctor search for things that don't look normal. You may have to wear a Holter monitor, a portable machine that records your EKG signals over 24 hours.
Event monitor. This is like a Holter monitor, but it records only a few minutes at a time several times a day. You might need to wear it for 30 days. When you feel symptoms, you might push a button to start the measurement. Or the device may detect changes in your heart rhythm and record automatically.
Exercise stress test. Your doctor will have you walk on a treadmill while they monitor your heart activity.
MRI: This measures the heart muscle's magnetic fields and looks for weaknesses.
Chest X-ray. This can show the condition of your heart and lungs.
CT scan of the heart. This test takes several X-ray images to give the doctor a more in-depth view of your heart. It's also called a cardiac CT.
Coronary angiogram. This test looks for blocked or narrowed blood vessels in the heart using dye and a special type of X-ray.
Electrophysiological (EP) study. This can help confirm that you have tachycardia and pinpoint where your heart's signals are misfiring. The test uses flexible tubes guided through a blood vessel, usually in your groin. The tubes have sensors that record the electrical signals in different parts of your heart.
Tilt table test. If your tachycardia causes you to faint, your doctor may order this test. You lie flat on a table while your heart rate and rhythm are checked. Then the table is moved up until you're in a standing position. The tests checks how your heart reacts when you're tilted up.
Tachycardia Treatment
Your treatment will be aimed at slowing your heart rate and preventing episodes of tachycardia in the future. If your tachycardia is caused by an underlying health problem, your treatment will address that, too. What type of tachycardia you have will determine how your health care team proceeds.
Supraventricular tachycardia treatment
Your doctor may recommend that you drink less caffeine and less alcohol, get more sleep, or quit smoking. You doctor also may prescribe medicine, which could include:
- Beta blockers
- Calcium channel blockers
- Antiarrhythmic drugs
- Blood thinners
You might need a procedure called cardioversion, which changes the rhythm of your heart. The doctor uses a defibrillator to give your heart an electrical shock (electrical cardioversion). The other approach (chemical cardioversion) uses drugs -- either oral or IV -- to change your heart rhythm.
Another procedure, ablation, uses a thin tube to destroy abnormal heart tissue that's causing your tachycardia.
Ventricular tachycardia treatment
Medicine, cardioversion, and ablation also are used to treat this type of tachycardia. Your doctor could recommend implanting a device to monitor your heart rhythm and administer electrical shocks to correct it when needed. It's called an implantable cardioverter defibrillator, or ICD. It's inserted under the skin of your chest and attached to your heart by small wires.
Sinus tachycardia treatment
If you have this type, your doctor will help you pinpoint the cause and suggest things to lower your heart rate. These might include lifestyle changes such as easing stress or taking medicine to lower a fever.
When to See a Doctor
A rapid heart rate doesn't always need treatment. But sometimes, it can be life-threatening. If you feel like your heart is beating too fast, make an appointment with your doctor for a checkup.
Some symptoms mean you should get help right away, from paramedics or at the ER. Those include:
- Pain or discomfort in your chest
- Weakness
- Shortness of breath
- Fainting, or almost fainting
- Dizziness or feel lightheaded
Ventricular fibrillation can cause the heart to stop altogether. Breathing may also stop. This is cardiac arrest.
If someone collapses and their breathing and pulse stop, you should:
- Call 911.
- Start CPR.
- Send someone to find an automated external defibrillator (AED). These portable devices often are found in public buildings, libraries, sports venues, and schools. You don't need special training to use it.
Takeaways
When you have tachycardia, your heart beats too fast -- more than 100 beats per minute when you're at rest. A number of things can cause this. Some, like exercise or stress, may not require any treatment. But other types of tachycardia can lead to life-threatening problems. Lifestyle changes such as limiting caffeine and alcohol and getting more sleep can help. If you need treatment, your doctor might prescribe medicine. You also might need a procedure or an implantable device to correct your heart rhythm.
Tachycardia FAQs
What is the cause of tachycardia?
Many things can cause tachycardia. Electrical signals in your upper (atria) or lower (ventricle) chambers of your heart might misfire. It also can be caused by simple things such as exercise, anxiety, some medications, or street drugs.
How do you fix tachycardia?
The fix might be as simple as lifestyle changes: cut down on caffeine and alcohol, and get more sleep. You may need medicine. Your doctor might recommend shocking your heart back into rhythm, using either electricity or medicine. A doctor might perform an ablation, creating scar tissue on your heart that will prevent incorrect electrical signals. If all other treatments fail, you may need open-heart surgery.
Is tachycardia dangerous?
Yes. If you have the ventricular type, you could experience cardiac arrest. That can be fatal if you don't get the right treatment immediately. Tachycardia also can raise your risk of stroke or blood clots.
Can tachycardia cause low blood pressure?
Yes. During ventricular fibrillation, your blood pressure can drop to a dangerous level, which can lead to cardiac arrest.
