Atrial premature complexes are also called premature atrial contractions (PACs) and may cause heart palpitations or unusual awareness of your heartbeats. Palpitations may be heartbeats that are extra fast, extra slow, or irregularly timed. PACs occur when a beat of your heart occurs early in the heart cycle or prematurely (CincinnatiChildren’s).
PACs result in a feeling that the heart has skipped a beat, or that your heartbeat has briefly paused. Sometimes, PACs occur and you can’t feel them. Premature beats are common, and usually harmless. Rarely, PACs may indicate a serious heart condition such as life-threatening arrhythmias.
When a premature beat occurs in the upper chambers of your heart, it is 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. 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) 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 beat is generally unknown. Most people who have PACs do not have heart disease (CardiacHealth). Any of the following can cause premature beats to occur more frequently, making you more likely to notice them:
- caffeine consumption
- alcohol consumption
- fatigue or poor sleep
- medication that lists irregular heartbeat as a side effect (such as Dostinex, Requip, Wellbutrin, Xanax, Depakane, Advair, and more)
PACs 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 is usually not dangerous unless you experience premature beats often, or they impact the quality of your life (CincinnatiChildren’s).
Sometimes, premature beats may be caused by 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 PACs with no symptoms. You may have premature beats without ever being aware of them. If you are able to feel the beats, you may notice any of the following when they occur:
- feel 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 PACs. They may also occur with other conditions that are often mistaken for PACs. Any of these could indicate that you may have a more serious heart condition. If you experience them, you should promptly seek medical care:
- skipping or racing sensation near the heart accompanied by fainting or lightheadedness
- you become 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
Sometimes PACs can be a symptom of a more serious condition. If you notice your heart skipping beats, racing, or pounding in combination with any of these symptoms, seek prompt medical care.
You may have any of the following conditions:
- 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)
- the valve separating the upper chambers of your heart from the bottom chambers does not properly close
- 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 is new and has not 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. He or she may ask you what you were doing when you first noticed the symptoms. He or she will also likely ask about your medical history.
Indicators of heart disease, such as diabetes, high cholesterol, high blood pressure, being overweight, smoking, and having a family history of heart disease may warrant a more thorough exam, even if PACs are not accompanied by any other symptoms.
Your doctor will conduct a physical exam to detect indicators of underlying problems with the heart, and to monitor the function of your heart. Procedures may include listening to your heartbeat, running 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 is triggering PACs. The pattern of disturbances can help your doctor understand what is causing them. This can be done with an electrocardiogram (a test that records the electrical activity of your heart, either during normal activity or during exercise).
You may also be instructed to wear a monitor for 24 to 48 hours or when symptoms occur. This monitor is worn under your clothing and records your heart rhythms as you go about your normal activities (MedlinePlus).
You should seek treatment any time you notice a change in your heartbeat that has not yet been discussed with your doctor. Most cases of PACs do not require care beyond an initial exam. If your doctor determines your PACs are not dangerous, you probably will not need to see your doctor if you experience them again, unless they are frequent, accompanied by other symptoms, or your doctor provides different instructions.
If your PACs are diagnosed as harmful, treatment usually addresses the underlying condition that is triggering the premature beats. Your doctor will recommend a customized plan based on the results of your exam.
Sometimes, harmless PACs are so frequent they can interfere with your day-to-day 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 (harmless) premature beats by avoiding substances such as recreational drugs, tobacco, alcohol, and caffeine (MayoClinic). Also, try to practice cardiovascular exercise on a regular basis. Anxiety contributes to PACs, so reduce your stress levels, or discuss anti-anxiety medication with your doctor. If you see a medical provider who is not familiar with your history, let him or her know to prescribe medications that are not likely to increase PACs.