A healthy heart beats in a steady rhythm, with the upper and lower chambers beating in a synchronized and consistent pattern. After each heartbeat is a pause, and then a predictable heartbeat, and then a pause, and so on.
But if you have a condition known as bigeminy, each normal heartbeat is followed by a beat that arrives too quickly. It’s a series of long and short beats. Each set of two beats is considered “twins,” hence the name: bi + gemini (Latin for “twins”).
Those early heartbeats are known as premature ventricular contractions (PVCs) if they emerge from your heart’s lower chambers, or the ventricles. They’re called premature atrial contractions (PACs) if they originate in your heart’s upper chambers, known as the atria.
During each heartbeat, your right ventricle pumps blood to your lungs to exchange carbon dioxide for oxygen. Your left ventricle pumps blood through your aorta to the rest of your body. While this is happening, your atria fill with blood and then move it down into the ventricles to get ready for the next heartbeat. Blood moves into your ventricles in between each heartbeat.
You’ll feel a “skipped beat” if a premature contraction occurs before your ventricles have filled with blood. The premature beat may feel different from a normal heartbeat because little or no blood is being pumped out of your heart. If your ventricles have had time to fill with blood, the premature beat will be more noticeable. As a result, you’ll have the sensation that your heart is beating faster than normal.
PACs and PVCs are common and often harmless. You can experience occasional PACs or PVCs without having bigeminy. But if the premature contractions are an ongoing problem, bigeminy can be a sign of heart trouble down the road.
You may not even be aware that premature contractions are happening. If you do notice symptoms, they’ll feel like changes to your regular heart rate. These may be mild, or they may make you feel acutely aware of how your heart is beating every moment. If you have bigeminy, you may feel that your heart is beating too fast or that your heart is skipping a beat.
The causes of bigeminy aren’t always clear. Heart disease or high blood pressure may create problems with your heart’s electrical system, which controls when and how forcefully your heart beats. Other potential triggers of premature contractions include:
- asthma medications and other drugs
- chemical imbalances in your body
The main test to diagnose bigeminy is an electrocardiogram (EKG). In an EKG, your doctor will place electronic sensors on your chest. These sensors painlessly record the electrical activity in your heart. The recorded information reveals the pattern of your heartbeats and can often identify the source of the unusual heart rhythm.
You may also undergo what is called an exercise stress test. In this test, you walk on a treadmill or ride a stationary bike while you’re hooked up to the EKG machine. This can help your doctor determine the severity of your bigeminy.
If your premature contractions disappear during exercise, they’re probably not a threat. If physical activity triggers additional beats, it could be a sign of a more serious heart rhythm disturbance. Another name for an abnormal heart rhythm is an arrhythmia.
One limitation of an EKG is that if you experience premature contractions just once in a while, there’s a chance they won’t be present during the test. Your heart may be behaving normally when you take the test. If this happens, your doctor may recommend you wear a 24-hour monitor such as a Holter monitor to catch the premature contractions whenever they occur.
If you don’t have some form of heart disease and you experience no noticeable symptoms, you may not need any treatment for bigeminy.
If you do need treatment, it may start with beta-blockers, medications that help relax your heart and lower blood pressure. Other medications include calcium channel blockers to help lower blood pressure and reduce your heart’s workload, and antiarrhythmic drugs that help restore your heart’s healthy, normal rhythm.
In very serious cases of bigeminy, if the portion of your heart that is causing the rhythm problem can be identified, a procedure called catheter ablation may be necessary. During this procedure, a thin, flexible tube known as a catheter is guided from a blood vessel in your leg up to your heart, where it sends a small charge of electricity to the tissue causing the electrical disturbance. The charge destroys the tissue, often ending the abnormal contractions.
However, catheter ablation isn’t always successful. Sometimes more than one attempt is needed, or surgery is required to treat the heart condition.
Most people experience premature heart contractions at some point in their lives without harm or complications. Children and adolescents are especially likely to experience harmless PVCs or PACs. However, if bigeminy symptoms are noticeable and ongoing, rather than mild and infrequent, the health concerns become much more serious.
Bigeminy can raise your risk of developing an arrhythmia such as atrial fibrillation, in which the upper chambers of your heart don’t beat in a coordinated pattern with the lower chambers.
When this happens, blood can pool in your atria and a clot can form. If the clot escapes your heart and makes its way up to your brain, it can cause a potentially fatal stroke.
The additional workload on your heart caused by the extra beats may lead to enlargement of the heart and possibly heart failure.
Because the cause of bigeminy is often unknown, prevention isn’t always possible. However, heart disease is a strong risk factor for bigeminy. Take care of your heart:
- Follow a heart-healthy (low-sodium, low-fat) diet.
- Exercise regularly.
- Quit smoking.
- Manage your blood pressure, cholesterol, and blood glucose levels.
Bigeminy can be brought on by a rush of adrenaline. Caffeine and nicotine can sometimes trigger adrenaline production, so avoiding those triggers may help keep your heart beating steadily. It can also help to keep track of any other triggers that may be bringing on contractions.
Stress and anxiety can also lead to heartbeat problems, so managing your stress with meditation and other relaxation exercises is recommended. Learning to reduce your stress can have wide-ranging health benefits, regardless of your heart condition.