Congenital Heart Disease

The Structural Heart Disease Program at the Heart & Vascular Institute-Texas Medical Center is staffed by specialists and subspecialists from the Division of Cardiovascular Medicine at The University of Texas Medical School at Houston, as well as by physicians in private practice.  The team includes noninvasive cardiologists, interventional cardiologists and cardiovascular imaging specialists.

Research focused on novel percutaneous and endovascular therapies for the treatment of structural heart disease has opened the door to new minimally invasive treatments for a variety of non-coronary artery diseases. The benefits for patients are significant: less bleeding and need for blood transfusion, a shorter hospitalization and faster recovery.

For individuals who are diagnosed with congenital heart disease as an adult, our affiliated physicians provide comprehensive care for all conditions, including:

• Atrial septal defects
• Ventricular septal defects
• Patent foramen ovale (PFO)
• Pulmonary arteriovenous fistulas
• Patent ductus arteriosis

For concerns related to congenital heart disease in children, physicians affiliated with the Children’s Heart Institute at Children’s Memorial Hermann Hospital provide care for neonatal and pediatric patients.

Clinical research at Memorial Hermann-Texas Medical Center and the UT Medical School has led to the development of innovative approaches to the treatment of structural heart disease. Clinical research team members serve as principal investigators in local, national and international research trials, and publish the results of their research in major subspecialty journals and general medical journals such as the American Journal of Cardiology, Clinical Research, Circulation, Circulation Interventions, Journal of the American College of Cardiology, Journal of the American College of Cardiology-Interventions, Journal of Nuclear Medicine and Catheterization and Cardiac Interventions, among others. 

To obtain a referral to a cardiologist affiliated with Memorial Hermann Heart & Vascular Institute-Texas Medical Center, call 713.222.CARE (2273). 

An atrial septal defect (ASD) (link to) is a hole in the part of the septum that separates the left and right atria, or upper chambers of the heart. A hole in the septum between the heart’s two lower chambers, or ventricles, is called a ventricular septal defect (VSD) (link to).

Atrial septal defects and ventricular septal defects allow blood to pass from the left side of the heart to the right side. In the normal heart, with each heartbeat, the right side of the heart receives oxygen-poor blood from the body and pumps it into the lungs. The left side of the heart receives oxygen-rich blood from the lungs and circulates it through the body. ASDs and VSDs allow the escape of some oxygen-rich blood into the lungs instead of pumping it through the body.

Many infants born with ASDs have no signs or symptoms. If symptoms occur, shortness of breath and irregular heart rhythms are the most common. Medium to large unrepaired ASDs may cause arrhythmias, stroke or pulmonary hypertension.

Moderate to large VSDs may lead to heart failure, arrhythmias or failure to grow, especially in infancy.

A patent foramen ovale (PFO) is a small opening between the upper chambers of the heart that allows blood to bypass the lungs. Normally, a PFO closes shortly after birth but estimates indicate that in 1 out of 4 people, the opening never closes. Researchers suspect that PFOs may contribute to cryptogenic strokes, which are strokes with an unknown cause.

The cause of PFOs is unknown, and there are no known risk factors. Occasionally, PFOs and ASDs are associated with shunting of blood from the right atrium to the left atrium. When this occurs, the oxygen content of the arterial blood can drop, causing severe shortness of breath. In addition, small blood clots (or in the case of recreational or commercial divers, air bubbles) in the blood that shunts into the left atrium may result in stroke or heart attack. This right-to-left shunting in patients with PFOs and ASDs has also been associated with migraine headaches in some studies. 

A pulmonary arteriovenous fistula is an abnormal connection, or fistula, that develops between an artery and vein in the lungs. As a result, blood passes through the lungs without receiving enough oxygen. 

Pulmonary arteriovenous fistulas are usually the result of a genetic disease that causes the blood vessels of the lung to develop abnormally. Fistulas also can be a complication of liver disease.

These fistulas can result in the same symptoms described above in patients with PFOs and ASDs with right-to-left shunting.

In patent ductus arteriosis, abnormal blood flow occurs between two of the major arteries connected to the heart. Before birth, the aorta and the pulmonary artery are connected by a blood vessel called the ductus arteriosus, an essential part of fetal blood circulation. 

While the vessel normally closes after birth, in some babies it remains open, allowing oxygen-rich blood from the aorta to mix with oxygen-poor blood from the pulmonary artery. The result is strain on the heart and increased blood pressure in the lung arteries.

Diagnosis

At the Memorial Hermann Heart & Vascular Institute-Texas Medical Center, our expert cardiologists will listen carefully to your heart with a stethoscope and use multiple imaging studies to diagnose structural heart disease, including: 

• Transthoracic echocardiography
• Transesophageal echocardiography
• Cardiac CT
• Cardiac MRI

Echocardiography

While cardiologists begin the diagnosis of heart valve disease by performing a physical exam, conducting an electrocardiogram and discussing signs and symptoms, the diagnosis is frequently confirmed with echocardiography. Echo is a noninvasive test that uses sound waves to create images of the heart while it beats.

Echocardiograms give cardiologists information about the size and shape of the heart and how well its chambers and valves are functioning. During the test, a device called a transducer is placed on the surface of your chest. The transducer sends sound waves through the chest wall to the heart, and echoes from the sound wave are converted into images of your heart on a computer screen. Echo can show the size and shape of the heart valves and chambers, how well the heart is pumping blood and whether a valve is narrowed (stenosis) or has backflow (regurgitation).

A two-dimensional transthoracic echocardiogram can evaluate cardiac structure and function, including left ventricular systolic/diastolic function. Doppler evaluates the flow through the valves.

Your physician may also recommend transesophageal echocardiography (TEE), which is complementary to the transthoracic echocardiogram, and produces a more defined image of the heart providing more detailed information about complex heart valve disease. During the TEE, a transducer is attached to the end of a flexible tube, which is guided down the throat and into the esophagus. A mild sedative is usually given before the procedure.

Cardiac CT

An advancing technology in the noninvasive evaluation of heart disease, cardiac CT provides information on the structure and function of the heart and its vessels. During the scan, an x-ray machine moves around the body in a circle, taking images of areas of the heart. Using the images, a computer creates a 3D view of the entire organ.

Cardiac MRI

Cardiac magnetic resonance imaging (MRI) uses a powerful magnet and radio waves to produce a detailed assessment of function and structure of the heart and its vessels. A cardiac MRI study can confirm structural heart disease defects and provide more detailed information about size, location and effect on heart function. It also provides information about the extent of scarring following a heart attack.

Treatment

Researchers and clinicians bringing groundbreaking discoveries from the laboratory to the bedside have made the Memorial Hermann Heart & Vascular Institute-Texas Medical Center one of the world’s leading cardiovascular hospitals. Physicians affiliated with the Institute use state-of-the-art techniques and technology. Because they are principal investigators in local, national and international clinical research trials, our patients have access to new medical therapies, innovative devices and technology very quickly after their introduction. Patients who qualify have the opportunity to participate in clinical trials of treatments not otherwise available.

Advances in interventional cardiology have made percutaneous catheter-based procedures the preferred approach to closing the most common type of atrial and ventricular septal defects. During the procedure, the interventional cardiologist inserts a catheter into a vein in the groin and threads it to the heart’s septum. When the catheter reaches the septum, a tiny, umbrella-like device is pushed out of the catheter and positioned to close the hole between the right and left chamber. The catheter is removed, and within a few months, normal tissue grows over the device.

Among the advances available through the Heart & Vascular Institute’s participation in clinical trials is percutaneous patent foramen ovale treatment using an occlusion device for patients who have recurring strokes with no apparent cause. A catheter threaded into a vein in the groin is guided into the heart, and the device functions as a plug to close the PFO. Closure prevents blood from passing through the PFO, reducing the risk of stroke. The Institute is one of the nation’s largest enrolling sites in the RESPECT PFO Clinical Trial, which is evaluating the Amplatzer device.

For most patients with fistulas, the treatment of choice is to block, or embolize, the fistula during an arteriogram, an imaging test that uses x-rays and a special contrast dye to visualize the interior of the heart’s arteries. Embolization is a non-surgical, minimally invasive procedure performed by a cardiac interventionalist.

Patent ductus arteriosis (PDA) is treated with medication, catheter-based procedures and surgery. The goal of treatment is to close the PDA to prevent complications and reverse the effects of increased blood volume.

Memorial Hermann Heart & Vascular Institute-Texas Medical Center

= Open to Enrollment

If you would like to learn more about participating in a research study or clinical trial, you may find our list of frequently asked questions (FAQ) helpful. If you have a question not addressed on our FAQ list, you may email us at research@memorialhermann.org.

Congenital Heart Disease

RESPECT Trial: Randomized Evaluation of Recurrent Stroke, TIA or Peripheral Embolism Comparing PFO Closure to Establish Current Standard of Care Treatment and Revision
Principal Investigator: Richard W. Smalling, M.D., Ph.D.

This study is investigating whether percutaneous (done by needle puncture of the skin) patent foramen ovale closure is equivalent to the current standard of care – medical management – in the prevention of symptomatic recurrent stroke, transient ischemic attack or peripheral embolism.