Dear Doctors: Is it true that if you have a normal heart, skipped heartbeats are generally harmless, especially if you also aren't having any shortness of breath or chest discomfort? Are there any hard and fast rules regarding how many daily skipped beats is safe or normal?
Dear Reader: It can be unsettling to feel like your heart has skipped a beat. Many people feel a sudden "thump" that alerts them to a change in the natural heart rhythm they are used to. This type of irregular heartbeat is common. Most people have it from time to time, often without even noticing. For people in good health with a normal heart, these errant heartbeats are usually harmless.
Although it feels like your heart skipped a beat, it's actually the opposite. A quick glitch in the heart's electrical system causes an extra beat too soon. This beat is often weaker than normal. The brief pause after gives the heart's main pumping chambers, the ventricles, more time to fill with blood. This causes the next heartbeat to feel stronger than usual. This creates the "thump" that feels like your heart is skipping a beat.
There are two types of these early heartbeats. The chamber of the heart that starts the early beat determines the type. The most common type is called a premature atrial contraction, also called a PAC. This occurs when one of the heart's two upper chambers, called the atria, beats too soon. The lower chambers, called the ventricles, can also beat too early. This is called a premature ventricular contraction, also called a PVC. PVCs are less common than PACs. Both types of early heartbeats, though, are harmless for people in good health.
Not all PACs and PVCs feel like skipped beats. They can also feel like a brief pause. They might feel like a flutter or a flip-flop. If you have several early heartbeats in a row, it can feel like your heart is racing. Caffeine, nicotine, alcohol, stress, poor sleep and certain medications can trigger PACs and PVCs. Conditions such as electrolyte imbalance, high blood pressure or thyroid disease can also cause them.
It's natural to want clear guidelines for heart symptoms and when to see a doctor. There is not one single rule that fits everyone on when early heartbeats become a concern. This is because they are so common. A few hundred early beats in a day can be normal, even for someone with a healthy heart. A much higher number of early beats may be enough to warrant some tests.
If you feel like you have skipped heartbeats often, talk with your doctor about your symptoms. A wearable monitor, such as a Holter monitor or Zio patch, can track how many early heartbeats you have. It can compare this amount to your normal heartbeats. This is called the "burden" of early beats. This information can help your doctor guide decisions about whether treatment may be needed.
(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
