Atrial Tachycardia

Overview

Atrial tachycardia is a rapid and usually regular heart arrhythmia that originates from the upper chambers of the heart (atria). Normally, the electrical signals that initiate the heartbeat come from the sinus node in the right atrium. In atrial tachycardia, however, electrical signals start abnormally from another area of the atria and the heart beats more than 100 times per minute, usually 150-250 times.

Atrial tachycardia belongs to the supraventricular tachycardia (SVT) group. This term describes rapid rhythm disorders originating from the upper part of the heart. Atrial tachycardia differs from other SVT types such as AVNRT and AVRT because the electrical signal forms and circulates entirely within the atria.

Atrial tachycardia appears in three main forms:

• Focal atrial tachycardia originates from a single point in the atrium.
• Multifocal atrial tachycardia involves electrical signals coming from multiple points and is usually seen in elderly people with lung disease.
• Atrial flutter and fibrillation are also technically types of atrial tachycardia but are usually classified separately.

Atrial tachycardia can come in episodes (paroxysmal) or be continuous (chronic). In some people no symptoms develop, while in others bothersome symptoms such as palpitations, dizziness, and fatigue occur.

Atrial tachycardia is usually not dangerous but if left untreated can lead to heart failure. Medication and catheter ablation are effective treatment options.

Symptoms

The symptoms of atrial tachycardia vary depending on how high the heart rate rises, how long it lasts, and whether there is underlying heart disease.

The most common atrial tachycardia symptoms are:

• Heart palpitations. Feeling the heart beating rapidly in the chest is the most common symptom. Palpitations are usually regular and can start and stop suddenly or be continuous.
• Dizziness. When the heart does not pump effectively, the brain may not receive enough blood and dizziness develops.
• Shortness of breath. Breathing can become difficult, especially during exercise.
• Chest discomfort. A feeling of mild pressure or discomfort in the chest may be felt.
• Fatigue. When the body does not receive enough blood, constant tiredness is felt.
• Fainting. Rarely seen but fainting can occur if the heart rate is very high.
• There may be no symptoms. In some people, atrial tachycardia is discovered by chance and no discomfort is felt.

In multifocal atrial tachycardia, symptoms are usually more noticeable because this type is often seen in people with serious lung disease. Shortness of breath and fatigue are more severe due to the underlying illness.

When to See a Doctor

See a doctor in the following situations:

• If you regularly experience heart palpitations, see a cardiologist.
• If chest pain, severe shortness of breath, or fainting develops together with palpitations, call emergency services immediately.
• If fatigue and reduced exercise capacity are gradually increasing, evaluation is important.
• If you happen to notice a rapid pulse, notify your doctor.

Causes and Risk Factors

The causes of atrial tachycardia vary by type.

Focal atrial tachycardia causes:

• Abnormal electrical focus present from birth. In some people there is an area in the atrium that spontaneously generates electrical signals.
• Heart disease. Heart attack, heart failure, and cardiomyopathy increase the risk of atrial tachycardia.
• Heart surgery. Scar tissue after surgery for congenital heart disease in particular can cause atrial tachycardia.
• High blood pressure. Uncontrolled high blood pressure enlarges the atria and increases the risk of tachycardia.

Multifocal atrial tachycardia causes:

• Chronic lung diseases. COPD, pulmonary fibrosis, and other lung problems are the most common causes.
• Heart failure. Advanced heart failure increases the risk of multifocal atrial tachycardia.
• Serious illnesses. Sepsis, kidney failure, and serious infections can trigger multifocal atrial tachycardia.
• Medications. Theophylline, caffeine, and some asthma medications increase the risk of multifocal atrial tachycardia.
• Electrolyte imbalance. Abnormal levels of potassium, magnesium, or calcium increase risk.

Other risk factors:

• Age. Risk increases with age.
• Excessive alcohol or caffeine use. Both can trigger atrial tachycardia.
• Thyroid disease. Overactive thyroid increases heart rate.
• Diabetes. Can lead to heart damage in the long term.
• Obesity. Excess weight puts extra load on the heart.

Complications

If left untreated, atrial tachycardia can develop some complications.

• Tachycardia-induced cardiomyopathy. Long-lasting rapid heartbeat can weaken the heart muscle. This occurs especially in continuous (chronic) atrial tachycardia. The heart enlarges and pumping strength decreases. Fortunately, when atrial tachycardia is treated, heart function usually improves.
• Heart failure. If heart failure already exists, atrial tachycardia can worsen the condition.
• Stroke risk. The risk of stroke in atrial tachycardia is lower than in atrial fibrillation but is not zero. Risk increases especially if heart failure or valve disease is present.
• Fainting and injury. Fainting can occur during atrial tachycardia and there is risk of injury from falling.
• Decline in quality of life. Constant palpitations, fatigue, and shortness of breath negatively affect daily life.

Diagnosis

Atrial tachycardia is diagnosed with an electrocardiogram (ECG) and other tests.

The diagnostic process typically includes:

• Electrocardiogram (ECG). This is the most important diagnostic tool. In atrial tachycardia, the shape and rate of P waves on the ECG are evaluated. P waves appear different from normal sinus rhythm. In focal atrial tachycardia, P waves appear uniform. In multifocal atrial tachycardia, however, at least three differently shaped P waves are seen and the rhythm is irregular. The ECG helps distinguish atrial tachycardia from other SVT types such as AVNRT and AVRT.
• Holter monitor. This is a portable ECG device worn for twenty-four hours or longer. It is used to capture intermittent atrial tachycardia episodes.
• Event recorder. This is a small device worn for weeks or months. You activate it when you feel palpitations.
• Echocardiography. This assesses the structure and function of the heart. Heart failure, valve diseases, and cardiomyopathy are detected.
• Electrophysiology study. In focal atrial tachycardia, the exact location of the electrical focus is determined. This is performed via cardiac catheterization and is usually used during catheter ablation for treatment purposes.
• Blood tests. Thyroid function, electrolyte levels, and kidney function are checked.
• Chest X-ray and tests. When multifocal atrial tachycardia is suspected, lung disease is investigated.

Treatment

Treatment for atrial tachycardia varies according to type, frequency, and underlying cause.

Focal atrial tachycardia treatment:

• Vagal maneuvers. In some cases, the Valsalva maneuver or cold water application can stop the tachycardia. It is not as effective as for AVNRT, however.
• Medication. Beta blockers, calcium channel blockers, or antiarrhythmic medications (flecainide, propafenone, sotalol, amiodarone) may be used. Medications help prevent episodes or slow heart rate.
• Catheter ablation. This is the most effective treatment for focal atrial tachycardia. A thin catheter is advanced to the heart through a vessel in the groin. The area where the abnormal electrical focus is located is destroyed with radiofrequency energy. The procedure takes one to two hours and has a success rate of 80-90 percent. Most people recover completely after the procedure. Ablation is preferred especially in continuous (chronic) atrial tachycardia and tachycardia-induced cardiomyopathy.

Multifocal atrial tachycardia treatment:

• Treatment of the underlying disease. This is the most important step. Lung disease is optimized. If infection is present, it is treated. Electrolyte imbalances are corrected. Triggering medications are stopped.
• Rate control. Beta blockers or calcium channel blockers help slow heart rate. In multifocal atrial tachycardia, however, medication response is usually poor.
• Magnesium supplementation. If magnesium levels are low, supplementation is given and can help rhythm improvement.
• Rhythm control medications are usually ineffective. In multifocal atrial tachycardia, antiarrhythmic medications rarely work.
• Catheter ablation is usually not appropriate. Because there are multiple foci in multifocal atrial tachycardia, ablation is unsuccessful.
• Stroke protection. In high-risk patients, blood thinner treatment may be considered.

Living with Atrial Tachycardia

In focal atrial tachycardia, most people recover completely after catheter ablation. In multifocal atrial tachycardia, control of the underlying disease is important.

If you have atrial tachycardia, pay attention to the following:

• Use your medications regularly. Use rhythm control, rate control, or blood thinner medications as your doctor recommends.
• Keep underlying diseases under control. If you have lung disease, use your medications regularly. Control your high blood pressure. Monitor your thyroid function.
• Avoid triggers. Stay away from excessive caffeine and alcohol consumption. Learn stress management techniques.
• Adopt a healthy lifestyle. Lose weight, exercise regularly, quit smoking if you smoke.
• Maintain your electrolyte balance. Especially in multifocal atrial tachycardia, your potassium and magnesium levels should be checked regularly.
• Have regular follow-up. Do not miss your cardiology appointments. Heart function should be monitored with echocardiography.
• Manage your COPD well. Use your inhaler medications regularly. Protect yourself from lung infections. Get oxygen therapy if needed.

Preparing for Your Appointment

What you can do:

• When did heart palpitations start and how often do they occur?
• Do palpitations start suddenly or gradually speed up?
• Do palpitations resolve on their own?
• What symptoms are you experiencing?
• Do you have lung disease?
• List all medications and supplements you are taking.
• Write your questions down in advance.

Questions you can ask your doctor:

• Is the diagnosis of atrial tachycardia certain?
• What type is it?
• What is the most appropriate treatment for me?
• How successful is catheter ablation?
• Can it affect my heart function?
• How long should I use medication?
• Can I exercise?

Your doctor may ask you:

• When did heart palpitations start?
• How do palpitations start and stop?
• What symptoms are you experiencing?
• Do you have lung disease?
• Are you using medication for COPD?
• Have you had heart disease before?
• What medications are you taking?