Heart Center
Single Ventricle Survivorship Clinic
Why a Survivorship Clinic?
With improving survival rates, the Single Ventricle Survivorship Clinic helps single ventricle patients achieve the good health necessary to enjoy life and to help manage any complications that arise related to single ventricle physiology. Since the health issues that Fontan patients experience can vary and often involve multiple organ systems, the Single Ventricle Survivorship Clinic uses a team approach and involves specialists from different medical fields to provide patient-centered, collaborative evaluation and treatments.
The Care Team
The Single Ventricle Survivorship clinic involves a multi-disciplinary team approach that collaborates to improve results. The team includes specialists in cardiology, gastroenterology, endocrinology, and pulmonary. Based on the individuals needs of each patient, the team may also include a hematologist, cardiothoracic surgeon, radiologist, and a holistic care provider.
What to Expect
Patients will be invited to visit the Single Ventricle Survivorship Clinic every three to five years, starting at five years of age. This clinic visit will be in addition to regular appointments. We will work closely with each patient's cardiologist and primary care physician to provide updates on the findings and recommendations of the clinic's different specialists. Cardiologists may refer a child to the clinic earlier than the age of five, particularly if the child develops Fontan complications like protein-losing enteropathy, plastic bronchitis, liver disease, or Fontan failure.
Common Tests & Appointment Preparation
Preparing for Your Appointment
Before your first appointment at the Single Ventricle Survivorship Clinic, please look over our clinic brochure so you know what to expect. Also, download our intake form and fill it out, so that you can minimize your time in the waiting room.
Remember to bring your photo I.D., insurance information, a list of medications, and the filled-out intake form with you.
Common Tests
Based on a patient's clinical condition and age, a variety of test may be performed to evaluate the health of their heart, liver, muscle, bones, blood, and lungs.
The Single Ventricle Survivorship Clinic will work with health insurance providers to try and obtain approval for all tests ordered. If a patient's primary cardiologist or other health care provider has already performed any of these tests, the clinic may not repeat them.
Bone Tests
Bone Health Blood Test
Serum Vitamin D, calcium, phosphorus, parathyroid hormones (PTH), reduced exercise capacity, delayed onset of puberty, and liver abnormalities may cause Fontan patients to have weak bones and muscles and vitamin D deficiency. The clinic will check blood levels of vitamin D and recommend vitamin D supplementation, as necessary.
DXA Scan to Measure Bone Health
Patients with the Fontan circulation commonly have low bone density. DXA is the preferred technique for measuring bone mineral density because it is relatively easy to perform and the amount of radiation exposure is low. Patients with low bone density will be referred to a specialist for further evaluation and treatment.
Bone Age & Sexual Maturity Test
Like other chronic diseases, chronic heart disease can delay the growth and maturation. A bone age study estimates the maturity of a child’s skeletal system which can help doctors diagnose delayed growth and development. It’s usually done by taking a low dose X-ray of the wrist, hand, and fingers. Sexual maturity will be assessed by the endocrinologist and your self-reporting of sexual maturity staging. If required, delayed growth and sexual maturation can be treated with medication.
Heart Tests
Electrical Activity Heart Tests
Multiple open-heart surgeries, in combination with single ventricle heart disease, can lead to scarring within the heart. The scarring can cause rhythm and electrical abnormalities in Fontan patients. Some patients will need a pacemaker that generates a low-energy electrical pulse to prompt the heart to beat at a normal rate. The clinic will evaluate the heart’s rhythm using these screening tests:
-
An Electrocardiogram (EKG or ECG)
An ECG translates the heart’s electrical activity into line tracings on paper giving information on heart rhythm and condition.
-
24-hour Holter monitor
Electrodes (small electricity-conducting patches) are stuck onto a patient’s chest and attached to a small recording monitor. The battery-operated monitor is carried in a pocket or small pouch worn around the patient’s neck or waist.
- The monitor records the heart’s electrical activity.
- Patients keep a diary of activities performed while wearing the monitor, noting how they feel.
- After 24-48 hours, patients will return the monitor to the clinic.
- A physician at the clinic will look at the recordings for any abnormal heart rhythms.
-
Pacemaker testing
Heart Failure Test
B-Type Natriuretic Peptide (BNP) is a substance secreted from the lower chambers of the heart (ventricles) that is caused by increased pressure from developing or worsening heart failure. We will check the BNP with a blood test.
Exercise Stress Test
An exercise stress test is an excellent way of monitoring heart performance and is a screening tool used to test the effects of exercise on the heart. To conduct the test, a patient walks on a treadmill or pedals an exercise bicycle. The patient will begin at a slow pace and will then be asked to walk or pedal faster and/or on an incline. During the test, the patient’s breathing, exhaled gases, electrocardiogram, blood pressure, and oxygen saturation will be monitored by an exercise technician. An exercise stress test can be a valuable tool to monitor and record changes in the performance of a patient’s heart over many years.
Cardiac Catheterization
Cardiac catheterization is a procedure in which a catheter (a thin flexible tube) is passed into either side of the heart by way of a blood vessel in the groin, neck, or arm. Most patients have had catheterization procedures as part of their previous evaluations. Cardiac catheterization is the only way to precisely measure pressures within the Fontan circulation and lung arteries. High Fontan pressures may indicate problems with the lung or heart function and may require additional investigation and treatment. Cardiac catheterization may also allow transcatheter interventions that can improve blood flow or heart function without surgery.
Cardiac MRI and CT Scans
Cardiac MRI uses radio waves, magnets, and a computer to create both still and moving pictures of the heart and blood vessels. Compared to echocardiograms, which are limited by the penetration of sound waves, cardiac MRI provides more detailed pictures of the beating heart and blood vessels in order to evaluate structure and function. Unlike CT scans, an MRI doesn’t use ionizing radiation, so it doesn’t increase the risk for cancer. Cardiac MRI is the only noninvasive imaging test that can differentiate healthy heart muscle tissue from dead or non-healthy tissue, while also providing valuable insight into heart function and determining if there is any narrowing in the arteries and veins. In patients with a pacemaker, ICD, or other metal implants, an MRI may not be recommended. These patients may undergo a CT scan instead.
Liver Tests
Liver Disease Blood Test
There has been growing awareness of the development of liver disease in Fontan patients. This is thought to be the result of a number of factors, including multiple surgeries, medications, overfilling of the veins with blood, and volume overload on the liver due to the lack of a ventricle to pump blood to the lung arteries. Blood tests and imaging studies
are used for ongoing monitoring because they are low-to noninvasive. The clinic uses a combination of blood and imaging tests to identify patients who should undergo a liver biopsy, which is an invasive test.
- Liver Function/Enzyme Tests
These blood tests help to determine liver health by measuring the levels of certain proteins and enzymes in the blood. - FibroSure
This noninvasive assessment of liver fibrosis analyzes 10 biochemicals in combination with age, gender, height, and weight. - Complete Blood Count (CBC)
CBC is one of the most commonly ordered blood tests because liver damage can affect the blood count. - Viral Hepatitis Test
Viral hepatitis can be a cause of liver dysfunction. - Alpha-Fetoprotein (AFP) Blood Test
AFP is a protein normally produced by the liver and is used for screening of liver disease and protein-losing diseases of the intestines.
Liver Biopsy
Liver biopsy remains the gold standard for assessment of liver disease. A liver biopsy is a procedure using a needle to remove a small piece of the liver so that it can be examined under a microscope for signs of damage or disease. The test is conducted in a hospital as an outpatient procedure. Before the test is administered, patients are given medicines for sedation and pain. It is important for patients to remain as still as possible during the biopsy, which is commonly done through the abdominal wall with patients lying on their backs. After cleaning and numbing the area, a biopsy needle is inserted. Ultrasound is typically
used to guide the needle or mark an optimal location. After the biopsy is obtained, the needle is removed quickly and a bandage is placed over the insertion site. The biopsy can also be done by inserting a needle into the jugular vein during cardiac catheterization. If the procedure is performed this way, X-rays will be used to guide the needle to the vein. A special needle and catheter is used to take the biopsy sample. Patients will need someone to drive them home.
Liver MRI & CT Scans
MRI scans provide detailed images of soft tissues in the body by using radio waves and strong magnets instead of X-rays. When MRI is used to look at the liver, several sets of images may be taken. After the first set is done, a contrast material called gadolinium is injected into a vein
in order to help show details more clearly. New sets of images are taken over the next several minutes as the gadolinium moves through the liver and other parts of the body. This is known as dynamic contrast-enhanced MRI, which is beneficial for viewing liver abnormalities like fibrosis and cirrhosis, and can help physicians discern between benign and malignant tumors. The scans can also be used to look at blood vessels in and around the liver.
For some patients, including those with metal implants such as a pacemaker or an implantable cardioverter-defibrillator (ICD), MRI is not feasible. These patients will have their livers evaluated with a CT scan. A CT scan is an X-ray test that produces detailed cross-sectional images
of the body. Similar to MRI, CT scans are helpful in looking at liver abnormalities like fibrosis, cirrhosis, and both non-malignant and malignant tumors, as well as nearby blood vessels.
Lung Tests
In single ventricle patients, after the Fontan procedure, the blood has to flow passively through the lungs without a pump. Since normal functioning of a Fontan circuit depends on the lungs being in good health, we will perform pulmonary (lung) function tests.
Spirometry
The health of the lungs will be assessed using spirometry which measures airflow by measuring how much air you inhale and how quickly the air is exhaled. During these tests you may be asked to perform a forced inhalation or exhalation after a deep breath, breathe normally and quietly or inhale a medicine to see how it changes your test results.
Plastic Bronchitis
Plastic bronchitis is a rare but serious lung complication that may develop following the Fontan operation. In plastic bronchitis, the lung is unable to clear the lymphatic secretions and large, rubbery, cheese like mucus cast forms within the airways which can obstruct the airflow
within the airways. In this condition, patients can have severe respiratory symptoms including breathing difficulty, low oxygen saturation and coughing episodes during which the mucus casts are coughed out. The Single Ventricle Survivorship team includes a pulmonologist who will evaluate, manage and follow patients with plastic bronchitis. With the newer treatment options, some patients with plastic bronchitis may improve without the need for cardiac transplantation.Other Tests
Blood Clotting
Patients with a single ventricle may have abnormalities in blood clotting that may predispose them to abnormal clot formation or bleeding. If indicated, tests for blood components and clotting will be performed.
Kidney Function Blood Tests
Undergoing multiple open-heart surgeries is a known risk factor for kidney damage.
- BUN and creatinine levels Blood tests of urea nitrogen (BUN) and creatinine levels are often done to assess how well the kidneys are working.
- Serum Vitamin D and PTH Reduced exercise capacity, delayed onset of puberty, and liver abnormalitiesmay cause Fontan patients to have weak bones and musclesand vitamin D deficiency. The clinic will check blood levels of vitaminD and recommend vitamin D supplementation, as necessary.
Loss of Protein
One of the most concerning complications of the Fontan operation is excessive loss of protein from the gut, known as Protein-Losing Enteropathy (PLE). A screening test for protein loss in the stool may be performed.