Premature Atrial Contractions

What Is Premature Atrial Contraction?

A premature atrial contraction (PAC) is an extra heartbeat that begins in one of the heart's two upper chambers (atria). A PAC may feel like your heart skips a beat. PACs usually don’t need treatment. However, you should contact a healthcare provider if you notice PACs that occur more frequently than usual.

Premature Atrial Contraction Symptoms

You may not have any symptoms during a PAC. When you have one, you might experience:

• The sensation of a skipped heartbeat
• A flutter in your chest
• A heartbeat that is stronger than normal
• Fatigue after exercise
• Shortness of breath or chest pain
• Lightheadedness or dizziness

What Causes Premature Atrial Contractions?

Doctors can’t always identify a cause for a patient’s PACs. However, causes of PACs can include:

• A change in the amount of blood passing through the heart.
• Injury to the heart.
• A problem with your heart’s structure, such as those caused by coronary artery disease or hypertrophic cardiomyopathy.
• Electrolyte imbalances (for example, too little or too much potassium or magnesium in your blood).
• Fatigue.
• Caffeine.
• Alcohol.
• Tobacco use.
• Stress.
• Certain medications, including ones prescribed for heart problems and mental health issues.
• Some recreational drugs.
• Thyroid problems

How Are Premature Atrial Contractions Diagnosed?

If you only have isolated or occasional PACs, you usually don’t need to seek medical treatment. If you have PACs often or if they bother you, you should talk to a doctor about them. Based on your symptoms, your doctor may order one or more of the following tests:

• Electrocardiogram (ECG or EKG): a diagnostic tool that records your heart’s electrical activity on a graph. An ECG can detect slow, fast or otherwise abnormal heart rhythms.
• Patch monitor: A portable version of an ECG, a patch monitor is a large adhesive patch that contains several electrodes. It can be worn on the chest to provide two weeks of nonstop heart monitoring.
• Exercise stress test: In this test, you’re attached to an ECG while you run on a treadmill or pedal on a stationary bike. A stress test shows how the heart reacts to exercise.
• Echocardiogram (echo): This test uses sound waves to create a moving picture of your heart. In addition to showing the structure of the heart and its valves, an echo can reveal areas of poor blood flow in the heart.
• Blood tests: Your doctor may order blood test to check your electrolyte levels and thyroid hormone levels.

Treatment for Premature Atrial Contractions

Most often, treatment for PACs is not needed. PACs generally go away on their own. If your symptoms are bothersome or if your PACs happen regularly, your doctor will treat the cause. Treatment options include:

• Medication: Your doctor may prescribe beta blockers or antiarrhythmics.
• Catheter ablation: Rarely, doctors may recommend a cardiac ablation procedure to treat more severe PAC case. In this procedure, your healthcare provider threads one or more thin, flexible tubes (catheters) through an artery, usually accessed in the groin, and guides them to the heart, without cutting your skin. Sensors at the tip of the catheter receive signals from your heart that help your doctor identify abnormal heart rhythm. Using the catheter, your doctor then applies heat (radiofrequency ablation) or extreme cold (cryoablation) to create tiny scars in the heart to block the irregular electrical signals that are disrupting your heart rhythm.