New insights about the 'extra' heartbeat in some people

People may feel a flip-flop in their chest when they're under stress, haven't slept well or even during normal activity. They may say, "I felt my heart stop for a second." But in most cases, that heart-stopping feeling is actually an extra heartbeat, called a premature ventricular contraction (PVC).

They're very common. Some people feel them, but others don't."

Dr. Sarah Hussain, cardiac electrophysiologist with Penn State Heart and Vascular Institute

PVCs most often originate in the bottom chambers of the heart. "A PVC is a wider looking heartbeat," said Barbara Bentz, a certified registered nurse practitioner with the Heart and Vascular Institute. "That extra beat is almost always followed by a pause, which occurs when the heart resets back to its normal beat."

For people who feel PVCs, they can seem frightening. "They are not always dangerous," Hussain said.

Causes of PVCs can vary. They may occur in high-adrenaline situations, triggered by stress or anxiety. Others may be side effects from certain medications. Sometimes electrolyte imbalances can cause PVCs. So can too much caffeine or alcohol.

PVCs can occur at any age, young or old. The causes of PVCs often varies depending on the age of the patient.

PVCs become more of a concern if they happen frequently. "If more than 10% to 15% of a person's heartbeats in 24 hours are PVCs, that's excessive," Bentz said. The more PVCs occur, the more they can potentially cause a condition called cardiomyopathy (a weakened heart muscle).

People who have experienced a prior heart attack-;or those already diagnosed with cardiomyopathy-;should also take PVCs seriously. So too should people who experience symptoms, which can include chest pain and shortness of breath, in addition to palpitations or skipped heartbeats.

The first step in diagnosing PVCs-;and learning whether they need treatment-;is an electrocardiogram (ECG), performed in a primary care doctor's office. A physician may recommend a wearable cardiac (Holter) monitor that will record a person's heartbeats over a 24-hour period. "That will quantify how many PVCs someone is having and the frequency of their PVCs," Hussain said.

In some cases, doctors may order an exercise stress test to see whether PVCs become worse with exertion.

Treatment for PVCs depends upon their cause. "If people only experience them when they have a large cup of coffee, then reducing caffeine intake is likely the answer," Bentz says. Other lifestyle changes may include reducing alcohol or energy drink consumption.

For people experiencing frequent PVCs, medications such as beta blockers, which slow heart rate, or calcium channel blockers, which relax the heart, may reduce the number of extra beats. Antiarrhythmic medications may also be used. If medication isn't effective or well tolerated because of side effects, doctors may recommend a minimally invasive procedure called cardiac ablation. It cauterizes the spot in the bottom chamber of the heart that causes the PVCs.

While most PVCs are harmless, people who experience any irregular heartbeat should call their doctor's office. "It may be PVCs or another type of arrhythmia," Hussain says. "So always ask to be evaluated and get an ECG."