Premature Ventricular Contractions

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What are premature ventricular contractions?

A premature ventricular contraction (PVC) is an extra and early heartbeat that begins in the heart’s lower chambers (ventricles), disrupting the fetus’ normal heart rhythm.

Premature ventricular contractions are a type of fetal cardiac arrhythmia, congenital heart conditions involving an abnormal heartbeat. Arrhythmias can cause the heart to beat too fast, too slow or in this case, irregularly.

In most cases, premature ventricular contractions don’t pose a health risk to the fetus and will resolve on their own. However, it is important for any irregular heartbeat to be properly evaluated, accurately diagnosed and closely monitored during pregnancy.

The condition is also sometimes referred to as premature ventricular complexes, premature ventricular beats or ventricular extrasystoles (additional heartbeats).

A Disruption in the Normal Heartbeat

Normally, the heart’s upper chambers (atria) and lower chambers (ventricles) alternately contract and relax in a steady rhythm to pump blood throughout the body.

This rhythm is controlled by the sinus node, a group of cells in the atria known as the heart’s “natural pacemaker.” The sinus node generates electrical impulses that begin in the upper chambers (atria), the atria contract, and then the signal transmits to the lower chambers (ventricles) and the ventricles contract. These contractions or pumps are your heartbeat or “normal sinus rhythm.”

Arrhythmias occur when something disrupts this process.

In a fetus with premature ventricular contractions, an extra contraction is triggered in the ventricles, before the next normal heartbeat begins, disrupting the normal order of pumping. This extra ventricular beat is typically followed by a short pause before the next regular heartbeat occurs, often more forcefully, making it seem as if the heart “skips a beat.”

How do premature ventricular contractions affect my baby?

Premature ventricular contractions are usually not harmful to the fetus. They typically resolve spontaneously during pregnancy or not long after birth, with no intervention required.

While uncommon, babies with this condition are at risk of developing a more serious form of fetal arrhythmia known as fetal supraventricular tachycardia (SVT), where the heart beats too fast. If the condition progresses to SVT, the fetus may be at risk of heart failure or a life-threatening condition known as hydrops (accumulation of fluid in multiple areas of the baby’s body) and treatment is necessary.

Cause and Prevalence

Fetal arrhythmias as a whole complicate an estimated 1 to 2 percent of all pregnancies. By far the most common type of fetal cardiac arrhythmia is a condition called premature atrial contractions (PACs). Premature ventricular contractions are about ten times less common than premature atrial contractions

The cause of most arrhythmias is unknown. Some cases may result from an electrolyte imbalance, inflammation, medication or an inherited genetic condition.

In rare cases, premature ventricular contractions may develop as a result of a serious congenital heart condition, such as structural heart defects, myocarditis (inflammation of the heart muscle), cardiomyopathy (diseases of the heart muscle), cardiac tumors, and long QT syndrome (fast, chaotic heartbeats).

Diagnosis

Premature ventricular contractions may be detected when the doctor listens to the fetal heartbeat or during a routine prenatal ultrasound.

In some cases rhythm abnormalities may not start until later in pregnancy. Generally, the mother has no symptoms and notices no change in fetal movement.

If an abnormal heart rhythm is diagnosed, prompt referral to a fetal cardiac center for further evaluation is vital to rule out structural anomalies and ensure accurate diagnosis and proper treatment. At Texas Children’s Fetal Center, we arrange for you to visit as quickly as possible for a comprehensive assessment by a team of specialists experienced in fetal cardiac arrhythmias, including maternal-fetal medicine (MFM) physicians (OB/GYNs specializing in high-risk pregnancies), fetal and pediatric cardiologists, fetal imaging experts, and pediatric electrophysiologists (specialists in heart rhythm problems).

Additional testing may include:

High-resolution anatomy ultrasound to confirm the diagnosis, evaluate the condition and look for other abnormalities
Ultra-fast MRI for a more detailed view of fetal anatomy
Fetal echocardiogram to assess fetal heart structure and function, and identify the type of arrhythmia
Doppler ultrasound to examine blood flow patterns
Amniocentesis and chromosomal analysis to screen for genetic abnormalities

Our specialists will then meet with you about the results, discuss treatment recommendations and answer any questions your family has, to help you make the most informed decisions regarding your baby’s care and treatment.

Treatment During Pregnancy

Treatment for isolated premature ventricular contractions, where no other conditions are present, is typically not required. The condition usually resolves on its own during pregnancy or shortly after birth.

However, because of the risk of developing a more serious form of fetal arrhythmia, your baby’s heart rate will be closely monitored throughout pregnancy. The goal is to detect the development of fetal supraventricular tachycardia (SVT), where the heart beats too fast, before it becomes life-threatening.

In some cases, you may be advised to reduce caffeine intake and stress. In rare cases, if the extra heartbeats increase and come consecutively, further treatment may be needed.

Delivery

In cases of isolated, infrequent premature ventricular contractions usually no special delivery planning or postnatal monitoring is needed. Following birth, should there be any concern for an irregular or fast heartbeat, an electrocardiogram (EKG) will be obtained to assess the fetal heart rhythm.

In cases of very frequent premature ventricular contractions or should the fetus develop supraventricular tachycardia, delivery should take place at a center with the highest quality congenital heart program, ensuring the expertise and resources required to treat fetal cardiac arrhythmias during delivery and at birth, including an advanced neonatal or cardiac intensive care unit (NICU or CICU), if needed.

Our Fetal Center team works closely with the pediatric experts at Texas Children’s Heart Center, a national leader in pediatric cardiology and heart surgery, for seamless access to the critical care services and specialists your child may need after delivery, avoiding the need for transfers. Here, the pediatric specialists treating your child have been an integral part of their care team since before birth.

Treatment After Birth

Treatment needs after birth vary based on each baby’s arrhythmia and any associated conditions.

In most cases, babies with premature ventricular contractions have a good prognosis with no long-term issues.

All babies should be followed closely by a pediatric cardiologist experienced in congenital heart conditions until the premature ventricular contractions have resolved.

Your baby’s care team after birth may include:

Why Texas Children’s Fetal Center?

A single location for expert maternal, fetal and pediatric care. At Texas Children’s Hospital, mothers and babies receive the specialized care required for the diagnosis and treatment of congenital heart conditions all in one location, for highly coordinated care and treatment planning.
A skilled, experienced team with proven outcomes. We have a dedicated team of maternal-fetal medicine specialists, fetal imaging experts, fetal and pediatric cardiologists, and neonatologists who work in concert to care for you and your baby every step of the way, using proven protocols we’ve developed over the years. With their combined expertise and unified approach, this team offers the best possible care for pregnancies involving fetal cardiac arrhythmias.
We care for your child’s needs at every stage of life. Our comprehensive approach starts with your first prenatal visit and continues through delivery, postnatal care, childhood and beyond, as needed, thanks to one of the nation’s leading teams of fetal and pediatric heart specialists

Texas Children’s Hospital – #1 in the Nation for Pediatric Cardiology and Heart Surgery

Our Fetal Cardiology Program is a collaboration between Texas Children’s Fetal Center and Texas Children’s Heart Center, ranked #1 in the nation for pediatric cardiology and heart surgery by U.S. News & World Report for consecutive years, with outcomes among the best in the country.

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Research and Clinical Trials

Texas Children’s, together with our partner institution Baylor College of Medicine, constantly strives to seek new and better treatments for babies with congenital heart conditions.

For more information, please contact the Cardiovascular Clinical Research Core at 832-826-2064 or email sandrea@texaschildrens.org.

Learn more about our fetal cardiology research.