A premature ventricular contraction is an occasional extra heartbeat that briefly throws off the heart’s regular rhythm. It arises prematurely (before the next heartbeat is expected) in the heart’s ventricles, the lower chambers of the heart. Some people with premature ventricular contractions can sense a fluttering in their chest. They may assume that their heart skipped a beat when it actually beat an extra time.

Most people—even children—have occasional premature ventricular contractions. They are expected and normal. These abnormal contractions are more common among men than women, older adults than younger adults, and people with heart disease than those without it.

In most cases, premature ventricular contractions are sporadic and harmless. They rarely require treatment. Some lifestyle changes may reduce the frequency of premature ventricular contractions, such as consuming less caffeine or adopting stress-reduction techniques.

However, people with certain heart conditions, such as cardiomyopathy (a heart-muscle disease), who experience frequent premature ventricular contractions may be at increased risk of death, including sudden death. Treating the underlying cause of the condition may eliminate these irregular contractions from recurring.

Some patients who experience a very high burden of premature ventricular contractions exceeding 20% (i.e., 1 in 5 heartbeats is a premature ventricular contraction) may develop a cardiomyopathy and experience heart failure, which is fully reversible with treatment of the premature ventricular contractions.

Premature ventricular contractions are extra, abnormal heartbeats that temporarily change a person’s heart rhythm. They occur when an electrical impulse fires from an unexpected area in the heart (the lower chambers), rather than from the part of the heart that is normally responsible for initiating the heartbeat (the upper chambers).

People may not know when they experience premature ventricular contractions. They may occur on occasion and are generally harmless in healthy people. The condition is more problematic if a person has underlying heart disease or cardiomyopathy.

The heart has four chambers. The two upper chambers are known as the atria, and the two lower chambers are known as the ventricles. The normal heartbeat process is initiated by muscle fibers known as the sinoatrial node, located within the right atrium of the heart. The sinoatrial node creates an electrical impulse that prompts the heart’s upper chambers (atria) to contract (squeeze), followed by contractions of the heart’s lower chambers (ventricles).

During a premature ventricular contraction, an abnormal electrical signal that originates in one of the heart’s lower chambers occurs after a normal heartbeat but before the next one. This abnormal beat disrupts the regular heart rhythm. It also causes a pause to occur before the next normal heartbeat.

Most of the time, there is no known cause for occasional premature ventricular contractions.

The following may cause some people to experience premature ventricular contractions:

• High caffeine consumption
• High anxiety levels
• Sleep deprivation
• The presence of the stress hormones adrenaline, norepinephrine, or dopamine
• Abnormal electrolyte levels (low magnesium, low potassium, or high calcium levels)
• Smoking
• Alcohol consumption
• Illegal drug usage
• Side effects caused by certain medications
• Cardiomyopathy, a disease of the heart muscle
• Mitral valve prolapse, when a valve within the heart doesn’t shut properly, allowing blood to leak backward from one heart chamber to another
• Heart attack
• Anemia
• Overactive thyroid (hyperthyroidism)
• High blood pressure

Many people don’t notice premature ventricular contractions. Other people may experience:

• Heart palpitations
• A fluttering feeling in the chest
• A sensation of an extra and/or skipped heartbeat
• Dizziness
• Fatigue
• Difficulty breathing

Most people experience premature ventricular contractions on occasion. The sensation may be more likely among:

• Males
• Older adults
• People with high blood pressure
• People with heart disease
• Taller people
• Sedentary people
• Smokers
• People with a family history of premature ventricular contractions
• People with a family history of sudden cardiac death

Some people with premature ventricular contractions seek a diagnosis from their doctors because they have felt heart palpitations or other symptoms and are worried about their heart health. Others never notice anything unusual, and doctors diagnose premature ventricular contractions when the patient is evaluated for another reason.

Doctors can diagnose premature ventricular contractions after learning about a patient’s medical history, giving them a physical exam, and offering diagnostic tests.

If you’re seeking a diagnosis, describe your symptoms to the doctor, and let them know how often you experience a fluttering sensation in your chest. If there are certain activities when your heart palpitations occur, such as during exercise, tell your doctor. Let your doctor know how much caffeine you consume regularly, whether you smoke, and how much pressure you’re under at work or home. It’s important to disclose how much alcohol you drink and whether or not you use illegal drugs, particularly if you experience frequent premature ventricular contractions. Your doctor will also want to know if you have a personal history of high blood pressure or heart disease and a family history of premature ventricular contractions or sudden cardiac death.

During a physical exam, your doctor will listen to your heartbeat, but it is unlikely that you’ll experience a premature ventricular contraction at that exact time. Doctors should perform a full physical, with an emphasis on heart health—for instance, checking your heart rate and taking your blood pressure.

Diagnostic testing, which may uncover premature ventricular contractions, includes:

• Blood tests. Doctors should check your blood to rule out other conditions or to look for underlying causes of premature ventricular contractions. They should check your potassium, magnesium, calcium, and thyroid hormone levels.
• Electrocardiogram. While lying on an examination table, a doctor attaches electrodes (sensors) to your chest, arms, and legs. Wires connect the sensors to an electrocardiogram machine, which records the electrical activity of your heart for several minutes. If you experience premature ventricular contractions during the exam, they will be recorded, but they may not arise during the short time frame of this test. The test may also identify other conditions with similar symptoms.
• Holter monitor. This device is sometimes known as an ambulatory or portable electrocardiogram. Your doctor places sensors on your chest that are attached to wires, which connect to the Holter monitor. It’s a small device that hangs on a long strap that can be worn over the shoulder or around your neck. A Holter monitor can record your heart’s electrical activity for 24 or 48 hours. The data over a two-day period is more likely than an electrocardiogram to pick up evidence of premature ventricular contractions.
• Event monitor. This device is similar to a Holter monitor except it can be worn for up to 30 days, recording the heart’s electrical activity.
• Echocardiogram. This test helps doctors see the heart’s structure in real time, while it is beating, using sound waves (ultrasound). As you lie on an examination table, a sonographer (a health care provider trained to use ultrasound equipment) places a transducer (an ultrasound wand or probe) in a number of locations to gather information about your heart’s function. The data is converted from sound waves into electrical impulses so that images appear on a screen. This test helps doctors rule out other problems relating to structural heart damage.
• Stress test or stress echocardiogram. During this test, doctors attach sensors to your chest, arms, and legs. The sensors are connected by wires to the echocardiogram machine, which uses sound waves to create images of your heart. Instead of lying on a table, you will be asked to walk on a treadmill or ride a stationary bicycle for about 15 minutes. Every few minutes, you’ll be asked to speed up and/or increase the incline of your walk so that you gradually exert more energy. This test may rule out other conditions, but it may provide useful information for people who experience premature ventricular contractions during or after exercise. If premature ventricular contractions cannot be induced during a stress test, they are typically not associated with health problems or an increased risk of death.

Doctors may not recommend treatment for premature ventricular contractions for most people.

Sometimes, doctors may suggest lifestyle changes. Possibilities include:

• Decreasing caffeine intake
• Limiting alcohol or drug use
• Quitting smoking
• Minimizing stress

Sometimes, doctors prescribe medication to manage premature ventricular contractions when they are frequent or if their presence bothers patients. Medications include:

• Beta-blockers or calcium channel blockers, which are often known as blood pressure medications. These two classes of drugs can help to control abnormal heart rhythms in patients who experience premature ventricular contraction symptoms.
• Anti-arrhythmic drugs, which help to correct heart rhythm problems. Doctors may prescribe amiodarone or flecainide for premature ventricular contractions.

Doctors also recommend catheter ablation to treat premature ventricular contractions. The treatment may be used in place of medication or offered to patients who no longer wish to take medication.

During the procedure, doctors, using live X-ray images for guidance, make a small incision in an artery in the groin, then thread one or more catheters (tubes) through the blood vessels until they reach the heart. They position the catheters in specific places within the heart, then place electrodes (sensors) at those locations to determine the exact location of the problem. Once the area is discovered, doctors send electrical energy through one of the catheters to the problematic area to burn the tissue causing the irregular heartbeats. After scar tissue forms, premature ventricular contractions should no longer occur.

In most cases, premature ventricular contractions will not affect a person’s short- or long-term health. However, people with cardiomyopathy, older adults with heart disease, and people who have recovered from heart attack who experience premature ventricular contractions are at increased risk of death, including sudden cardiac death. Some patients with a high burden of premature ventricular contractions may develop a reversible cardiomyopathy and heart failure.

“At Yale, we tailor the treatment of arrhythmias to each patient,” says Joseph Akar, MD, PhD, director of Yale Medicine’s Electrophysiology & Cardiac Arrhythmia Program. “In addition to offering the latest cutting-edge technology, Yale electrophysiology has expertise in treating complex arrhythmias while minimizing—or completely eliminating—patient exposure to ionizing radiation. We train physicians from all over the country and the world in these techniques, and we lead clinical research efforts that allow us to offer state-of-the-art therapy for arrhythmias.”