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Single Ventricle Heart Defects

What Is a Single Ventricle Defect?

A single ventricle defect is an umbrella term used to describe several different types of congenital heart disease (CHD). These defects all share the same problem: the heart has only one functional pumping chamber (ventricle), instead of the typical two (one on the right and one on the left). In babies with a single ventricle heart defect, one of the two ventricles is either not fully formed or not functioning correctly. In some types of single ventricle, such as tricuspid atresia and hypoplastic left heart syndrome, there are two ventricles, but one is very small (hypoplastic) and cannot function as a pump. In some cases, a valve or an entire chamber may be absent from the heart. Children with single ventricle heart defects are cared for by the specialists in the Single Ventricle Center of Excellence. While the single ventricle team cares for many children with single ventricle heart defects, they are rare, affecting only about 5 out of 100,000 newborns.

Whether children are born with only one ventricle or only have one ventricle that functions normally, the single pumping chamber must do the work for both sides. In these defects, oxygen-poor (blue) blood and oxygen-rich (red) blood is pumped from the right and left atrium to the single ventricle where they mix. This mixed blood then gets pumped to both the pulmonary arteries (which go to the lungs) and to the aorta (which goes to the body). In some cases, there is an obstruction in the aortic or pulmonary valves or the area underneath them. This will determine how much blood gets pumped to the body versus the lungs. The mixing of blood can cause babies to become cyanotic (blue or purple tint to lips, skin, nails), have difficulty feeding, difficulty breathing, and/or have lethargy (sleepiness). Every child is different in exactly how much oxygen or how little oxygen is in their blood depending on their CHD lesion, location, and severity of the defect. For example, some children will only be mildly cyanotic at birth, and others may be very blue and require early intervention. 

Eventually, all patients with a single ventricle will need one or more surgeries which allow the blue blood to drain to the lungs by gravity, flow to the single ventricle, and get pumped to the body. The last of these surgeries is known as the Fontan operation.

Types of Single Ventricle Defects


Diagnosing & Managing Single Ventricle Defect

Some infants will have a single ventricle defect diagnosed before they are born, and others will be diagnosed after birth. Prior to birth, a defect can be detected from a mother’s fetal echocardiogram. The diagnosis is then confirmed with an echocardiogram after the baby is born. Once the diagnosis is made, babies will usually require hospitalization in a specialized cardiac care unit for initial stabilization. It is important for there to be a balance between the blood flow to the lungs (to pick up oxygen) and the blood flow to the body (to provide oxygen and energy to the vital organs). In some cases, this will require an initial procedure within the first 1-2 weeks of life. Once the circulation is stabilized, babies with single ventricle heart disease will be followed closely by a specialized team in preparation for what is usually multiple additional operations. This journey described in more detail on our Single Ventricle Roadmap.

Single Ventricle Care at Lurie Children’s

The Single Ventricle Center of Excellence, at Lurie Children’s offers longitudinal comprehensive treatment for patients born with single ventricle heart defects in an environment that supports the whole family. The complex anatomy of the heart and its chambers makes each single ventricle defect different and each child’s journey unique. Children born with these complex hearts need specialized treatment, evaluation and lifelong follow-up care. Our team cares for patients from before birth through adulthood. We are dedicated to improving patient surgical, medical, neurodevelopmental, and psychosocial outcomes so that our patients can lead meaningful and active lives.

We care for patients anywhere along their single ventricle journey in a variety of care settings – from pregnancy by our multidisciplinary prenatal team in collaboration with The Chicago Institute for Fetal Health to adulthood as they begin the transition to our Adult Congenital Heart Disease Program. Learn more about the stages of care available through our Single Ventricle Center of Excellence

Why Choose Lurie Children’s Single Ventricle Center of Excellence

Our Single Ventricle Center of Excellence team is led by Kiona Allen, MD, and Michelle Steltzer, APN, is composed of experts in the diagnosis and treatment of patients with all types of single ventricle physiology. Our center brings together a full range of specialists to help guide you and your family through all components of your child's journey. Our multidisciplinary team includes clinicians from Cardiovascular Surgery, Cardiology, Clinical Nutrition, Palliative Care and Developmental Therapies. Depending on the needs of each patient, additional referrals are made to a variety of other specialties.

Our team meets weekly to discuss and decide on a care plan for each patient, which allows multiple heart doctors to weigh in on treatment options for your child. Single ventricle physiology is typically treated through a series of two or three palliative (non-curative) surgeries in the first few years of life. Despite many advances in the single ventricle care over the past several decades, these children often face additional difficulties with their heart and other organ functions in the long term - requiring future operations, complex testing, multiple hospitalizations, and frequent outpatient follow up. Our single ventricle team is uniquely equipped to help patients and their families face these challenges both inside and outside the hospital.

In some cases, the Fontan circulation is eventually unable to pump enough oxygenated blood to the body and vital organs leading to worsening heart failure, arrhythmias, and problems with the other vital organs. The Single Ventricle Team partners directly with our Pediatric Heart Failure and Heart Transplant Program, the only program of its kind in the state and a leading transplant program in the country, to support children and adults with Failing Fontan physiology they move towards a heart failure and/or heart transplant evaluation. Adult patients may also be referred to our internationally respected Fontan Conversion and Arrhythmia Surgery program, among the largest in the world.

Passionate about pioneering advancements and improvements in the diagnosis, treatment and care of patients with single ventricle physiology, our team participates in multiple quality and research initiatives centered around improving outcomes for these complex patients. Our program is also leading the field of cardiac stem cell therapy through our Fontan FuturesSM Initiative and our ground breaking NIH-funded clinical stem cell trials led by Sunjay Kaushal, MD, PhD

As your child grows, Lurie Children’s Heart Center also understands that your child needs more than just a healthy heart to thrive. Our NICU-Cardiac Neurodevelopmental Program provides close monitoring of our complex patients from early childhood in the NICU-Cardiac Neurodevelopmental Program: Early Childhood Clinic through school age in the NICU-Cardiac Neurodevelopmental Program: Child & Adolescent Clinic. We recognize that supporting the whole family is important. For families traveling from a distance we have easy access to a close-by Ronald McDonald House, built in 2012, with 70 private guest rooms. We are within the Northwestern Memorial Hospital complex, and for our patients who need transitioning to adult care, we have an integrated program in partnership with Northwestern Medicine to bridge patients to adult congenital care. We know that children born with single ventricle and their families face difficulties, but our Heart Center Team will partner with you to provide expert, innovative, compassionate, and individualized care for your child, allowing them to meet these challenges throughout their childhood and beyond.

Heart Center Family Resource Guide

To help prepare families for their care with Lurie Children's Heart Center, we have compiled a list of resources about treatment and recovery. Learn how to get ready for an inpatient stay or outpatient visit, and read about our support services for patients and families.