In a normal heart rhythm, your heart beats in a steady, even way. The upper part of your heart (atria) squeezes and pushes blood to the lower part (ventricles), pumping blood and oxygen out to the body.
Sometimes, an extra heartbeat that starts in the lower ventricle disturbs your regular heart rhythm. It’s known as a premature ventricular contraction (PVC, also premature ventricular complex). When PVC happens in a pattern of three beats, doctors call it trigeminy. It can feel like fluttering in your chest or a skipped heartbeat.
There are two kinds of trigeminy:
- Two normal heartbeats followed by one extra beat
- One normal beat followed by two extra beats
Trigeminy is common and happens in many healthy people. But it’s not how the heart normally works.
Specialized cells in your heart’s right atrium called the sinus node (sinoatrial, or SA, node) usually control its rhythm. The SA node acts as a natural pacemaker, creating the electrical impulses of a normal heartbeat. These impulses then move across the heart’s chambers, causing them to squeeze and pump blood to your body.
Trigeminy is a three-beat tightening or contraction that starts in the ventricles. The extra contractions happen sooner than your next usual heartbeat and disrupt the regular pumping order.
Doctors aren’t sure why these extra beats happen, but they do know there are certain triggers:
- Medicine to treat congestion (decongestants) and allergies (antihistamines)
- Illegal drugs such as cocaine
- Caffeine, tobacco, exercise, and anxiety linked to an increase in adrenaline, a hormone that gives you extra energy
- Injury of the heart muscle from heart disease, high blood pressure, and heart failure
Research shows that you’re more likely to get PVCs like trigeminy if you’re a man, African American, or an older adult. It’s not clear why that is.
You may not have any symptoms, or very few, which cause an uncomfortable feeling in your chest:
- Fluttering in the chest or neck
- Hard beating, throbbing, or jumping
- Skipped or missed beats
- You’re more aware of your heartbeat
The extra beats can be strong enough to be painful. If they happen often enough to reduce pumping in your heart, you could feel weak, dizzy, or even faint. And if you have heart disease, trigeminy contractions can lead to unsafe heart rhythms and sudden cardiac death, but this is rare.
Since the extra heartbeats of trigeminy happen randomly, it can be hard to diagnose. In healthy people, doctors often discover it by accident during a routine electrocardiogram (EKG), a test that measures electrical activity in the heart. They also sometimes find it while testing you for heart disease.
If you have symptoms of trigeminy, an EKG (also called ECG) can spot the extra beats and find a pattern and source for them. There are different types of EKG testing, and your doctor will choose the right one based on your symptoms:
Standard EKG. In a clinic or at the hospital, a technician will attach sensors called electrodes to your chest and limbs to track electrical signals moving through your heart.
If your symptoms happen only now and then, your doctor may send you home with a portable EKG that monitors your heart’s activity for 24 hours or longer:
Holter monitor. This is a camera-sized device carried in your pocket or a pouch. It measures and records your heart’s activity around the clock for 1 or 2 days.
Event recorder. When you feel symptoms, press a button on this portable device, and it records and stores your heart’s electrical activity. You’ll wear it for several weeks.
Another type of EKG, an exercise stress test, records your heart’s electrical activity while you use a treadmill or exercise bike. It helps your doctor figure out if physical activity triggers your trigeminy. You may start with one of the portable devices and later have to do an exercise stress test.
If you’re healthy and have symptoms of trigeminy only every once in a while, you won’t need treatment. But if you often have uncomfortable symptoms or heart disease, your doctor could recommend medication and lifestyle changes:
Medications. Beta-blockers curb early heart contractions, while calcium channel blockers and anti-arrhythmic drugs are for trigeminy that affects how well your heart works.
Lifestyle changes. Cutting back on triggers like caffeine and tobacco can help. Managing anxiety may also ease your symptoms.
Ablation. Doctors use radiofrequency waves to destroy small amounts of tissue near the source of your extra heartbeat. This procedure is for people with regular, long-term symptoms who can’t take medication.