Atrial premature complexes (APCs) are a common kind of heart arrhythmia, or heartbeat that is beating too fast, too slow, or irregular. Another name for atrial premature complexes is premature atrial contractions. One of the most common symptoms of APCs is heart palpitations or unusual awareness of your heartbeats. Palpitations are heartbeats that are extra fast, extra slow, or irregularly timed. APCs occur when a beat of your heart occurs early in the heart cycle. Another name for this is a premature beat.
APCs result in a feeling that the heart has skipped a beat or that your heartbeat has briefly paused. Sometimes, APCs occur and you can’t feel them. Premature beats are common, and usually harmless. Rarely, APCs may indicate a serious heart condition such as life-threatening arrhythmias.
When a premature beat occurs in the upper chambers of your heart, it’s known as an atrial complex or contraction. Premature beats can also occur in the lower chambers of your heart. These are known as ventricular complexes or contractions. Causes and symptoms of both types of premature beats are similar.
Your sinus node is an area of cells in the upper right chamber of your heart. It controls the pace of your heartbeat through electrical signals. Sometimes, signals from the ventricles (blood-pumping chambers) of your heart cause a heartbeat that comes earlier than the natural, normal rhythm. This is followed by a pause, and then a stronger second beat because the pause allows more time for blood to fill the heart chamber.
The cause of a premature heartbeat is generally unknown. Most people who have APCs don’t have heart disease, according to Cardiac Health. Any of the following conditions can cause premature heartbeats to occur more frequently, making you more likely to notice them:
- fatigue or poor sleep
- medication that lists irregular heartbeat as a side effect
APCs could mean you have extra connections in your heart’s electrical system. These extra connections may cause your heart to occasionally beat irregularly. Although this may be frightening or annoying, it’s usually not dangerous unless you experience premature beats often or they impact the quality of your life.
Sometimes, premature beats are due to an injury to your heart or underlying heart disease. If you suddenly begin to experience skipping heartbeats, or if your heart feels different in any way, you should have your doctor examine you to rule out an underlying problem.
Many people experience APCs with no symptoms. You may have premature beats without ever being aware of them. If you’re able to feel the beats, you may notice any of the following feelings when they occur:
- as though your heart skipped a beat
- heartbeats temporarily feel intensified or stronger
- a fluttering sensation near your heart
The following symptoms may occur along with APCs. They may also occur with other conditions that are often mistaken for APCs. Any of these could indicate that you may have a more serious heart condition. Promptly seek medical care if you experience:
- skipping or racing sensation near the heart, accompanied by fainting or lightheadedness
- becoming sweaty or pale when you notice your heartbeats have changed pace
- chest pain
- difficulty breathing
- experiencing more than six instances per minute of heartbeats coming in groups of three or more
- a resting pulse reading of more than 100 beats per minute
APCs can sometimes be a symptom of a more serious condition. If you notice your heart skipping beats, racing, or pounding in combination with any of the symptoms, seek prompt medical care.
Possible underlying conditions could include:
- dangerous arrhythmias that may lead to stroke or heart failure
- heart disease, which may include infection, genetic defects, and narrow or blocked blood vessels
- hypertension (high blood pressure)
- malfunction of the valve separating the upper chambers of your heart from the bottom chambers
- ventricular tachycardia, a disorder that causes a rapid heart rate and may lead to heart attacks
If you experience premature beats occasionally without any other symptoms, the beats are probably not dangerous. You should, however, seek treatment any time you notice a sensation in your heart that’s new and hasn’t been previously discussed with your doctor.
Your doctor will probably first ask you some questions if you experience sensations of skipping, racing, or pounding heartbeats. They may ask you what you were doing when you first noticed the symptoms. They will also likely ask about your medical history.
The following are indicators of heart disease and may warrant a more thorough exam, even if APCs don’t accompany any other symptoms:
- high cholesterol
- high blood pressure
- being overweight
- having a family history of heart disease
Your doctor will conduct a physical exam to look for indicators of underlying problems and to monitor the function of your heart. Procedures may include listening to your heartbeat, blood tests to check your chemistry and cholesterol levels, and testing your blood pressure.
Your doctor will monitor your heart rate if your exam suggests you may have an underlying problem with your heart that’s triggering APCs. The pattern of disturbances can help your doctor understand what’s causing them. This can be done with an electrocardiogram (EKG). An EKG is a test that records the electrical activity of your heart, either during normal activity or during exercise.
You may also need to wear a monitor for 24 to 48 hours or when symptoms occur. You wear this monitor under your clothing, and it records your heart rhythms as you go about your normal activities.
You should seek treatment any time you notice a change in your heartbeat that hasn’t yet been discussed with your doctor. Most cases of APCs don’t require care beyond an initial exam. If your doctor determines your APCs are not dangerous, you probably will not need to see your doctor if you experience them again, unless they’re frequent, accompanied by other symptoms, or your doctor provides different instructions.
If your doctor diagnoses your APCs as harmful, treatment usually addresses the underlying condition triggering the premature beats. Your doctor will recommend a customized plan based on the results of your exam.
Sometimes, harmless APCs are so frequent they can interfere with your daily life. If this is the case, your doctor may prescribe medicine such as beta blockers, or drugs used to treat more serious cases of arrhythmia. These drugs typically suppress contractions.
You can prevent benign, or harmless, premature beats by avoiding substances such as recreational drugs, tobacco, alcohol, and caffeine. Also, try to practice cardiovascular exercise on a regular basis. Anxiety contributes to APCs, so reduce your stress levels or discuss anti-anxiety medication with your doctor. If you’re overweight, try to follow a weight loss program that’s healthy for your heart. If you see a doctor who’s unfamiliar with your history, let them know to prescribe medications that aren’t likely to increase APCs.