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"Every day I get more relaxed," Stickles said. "I know this procedure is just routine at Vanderbilt now, but when it's your child, it's anything but routine. It's a modern day miracle."

Closing ASDs is just part of a larger pediatric cardiology program that didn't exist prior to the arrival of Thomas P. Graham, M.D., professor of Pediatric Cardiology, in 1971. In 34 years, since his arrival, Vanderbilt's pediatric cardiology division has grown to be one of the most highly regarded programs of its kind in the country.

"We started out with one clinic, one day a week," Graham said. "The first year, we did about 100 cardiac catheterizations and about 100 cardiac operations. The advances have been incredible, and we're doing a lot more non-invasive procedures."

Currently, pediatric cardiologists perform some 450 catheterizations and 400 operations each year. There's been a recent upsurge in the areas of pediatric interventional cardiology and fetal cardiology.

The pediatric interventional cardiology program, which began 11 years ago, deals specifically with the mechanical treatment of heart diseases. It's a relatively new field where traditional surgical procedures are now performed during a heart catheterization.

These procedures include opening narrowed areas with balloons and stents, closing unwanted vessels with coils or intravascular devices, and ablation for unwanted rhythm problems.

"This is one of our biggest programs now," said H. Scott Baldwin, M.D., Katrina Overall McDonald Professor of Pediatrics, who was recently appointed to succeed Graham as chief of the Division of Pediatric Cardiology. "We used to do open heart surgery for nearly every condition, now we can often use a catheter."

Thomas P. Doyle, M.D., the Ann and Monroe Carell Professor of Pediatric Cardiology, came to Vanderbilt to build the program in 1994. Doyle said that Vanderbilt was the first in Tennessee to address the following areas of pediatric interventional cardiology: closing atrial septal defects; closing patent foramen ovales; closing ventricular septal defects; closing patent ductus arteriosis; and performing stent therapy for congenital heart disease.

About 440 pediatric patients each year require catheterization, and about 270 of those receive some sort of interventional cardiology procedure. Children's Hospital likely treats the largest number of patients in the state, according to Doyle.

With recent advancements in the field, Doyle says there are conditions that can now be fixed surgically that previously had no other options. A child who may not have been well enough to survive open heart surgery may be eligible for a combined approach where the outcome is probably much better.

"The key to being successful is to have a dedicated cath lab staff," said Doyle. "We're blessed to have them. The other key is to have a very strong collaborative relationship with the cardiothoracic surgeons."

A fourth-year fellowship in the subspecialty has been created, and the first fellow has completed the training.

"One of the joys of working in an academic center is being able to train somebody to do what you love to do," Doyle said. "There are fellows each year who train in the basics of catheterization and general pediatric cardiology. But the opportunity to train in the sub-specialty of interventional cardiology, for me, is an additional excitement."

Doyle plans to train an additional new fellow each year with support from the Carell Chair endowment.

Pediatric ablation services
One very successful form of pediatric interventional cardiology is radiofrequency ablation (RFA). RFA was developed in the 1990s as a catheter-based technique for curative therapy of various abnormal cardiac rhythms. The source of the abnormal rhythms is identified and eliminated with heat by applying radiofrequency electrical current at the site.

RFA is now used to treat a wide array of arrhythmias. Patients may include younger ones who have irregular rhythms that are difficult to manage with medications; those with congenital heart disease; or those who have other medical problems which make it difficult to manage their conditions medically. In older patients, including adolescents and teenagers, RFA may be used as the primary therapy soon after diagnosis of the abnormal rhythm.

The Pediatric Arrhythmia Service at Children's Hospital has a very active RFA program. Seventy to 80 ablations are performed each year at Children's Hospital in children and adults with congenital heart disease. The volume continues to increase, and appears likely to exceed 100 ablations in 2005.

Adults with arrhythmias associated with congenital heart disease are often treated at Children's Hospital. Their arrhythmias are often complicated by their complex cardiac anatomies and subsequent cardiac operations, such that each case presents unique complexities.

Because of the familiarity with these complex anatomic variations and the availability of specialized 3-D anatomic mapping techniques available at Children's Hospital, these procedures are typically performed at VCH.

Frank Fish, M.D., associate professor of Pediatrics, helped start the RFA program at Vanderbilt in 1992, first in adults, and in children soon thereafter. In addition to performing nearly 800 ablation procedures in children, he has actively participated in more than 300 adult RFA procedures over the years, particularly in complex or difficult cases. With an overall success rate of over 98 percent, the pediatric ablation program at Vanderbilt is one of the more successful programs in the country. Most procedures are performed with Fish and Prince Kannankeril, M.D., assistant professor of Pediatrics, working in tandem.

"We've been particularly active and successful at targeting some of the more difficult and complex arrhythmias - especially in adults with congenital heart disease where we now are successful in more than 95 percent of cases," Fish said.

Added Baldwin, "Basically no one has better results than Frank."

Two newer innovations have been employed since the move to the new Children's Hospital. One of these is an ultrasound-based 3-D mapping system. Using highly sophisticated and targeted 3-D cardiac mapping, Fish and Kannankeril can accurately identify and localize an arrhythmia in complex underlying anatomy and promptly treat the condition -- all in one procedure.

Often, these arrhythmias are related to surgical scars, which create an abnormal electrical pathway or "short-circuit" within the heart. The electrical activity of the heart can be recorded and displayed in real-time on 3-D, color-coded cardiac maps. This helps to accurately determine the location of the abnormal circuit, along with the orientation and location of the mapping and ablation catheter. Then ablation is used to heat the abnormal circuit, blocking the abnormal conduction pathway, and eliminating the arrhythmia.

Newer yet is the use of cryoablation for certain ablation procedures.

Children's Hospital is the first pediatric or adult center in the state to acquire the equipment to perform cryoablation. Rather than heating the tissue, the new technique freezes tissue to ablate arrhythmias. This technique is particularly useful in treating arrhythmia sites lying close to normal electrical structures. This decreases the risk of damage to the underlying normal electrical system of the heart.

"Along with high success rate, we are equally proud of having probably the lowest rate of heart block among pediatric centers around the country. Still, we hope to make the procedure even safer by using cryoablation when working close to the normal electrical system."

Prenatal diagnosis
Even before a child is born, doctors can look for potential cardiac problems. The Fetal Cardiology Clinic screens about 200 patients each year for prenatal congenital heart disease through a non-invasive ultrasound, also called an echocardiogram.

From 18 weeks on, a mother can be referred to the Fetal Cardiology Clinic if she exhibits one of a variety of potential risk factors, affecting the mother or the baby. Such risk factors can include diseases affecting the mother, such as diabetes, or medications, including some antidepressants, which can be associated with the development of heart disease in the fetus. Other concerns about the fetus at the time of routine obstetric evaluation may prompt a request for a fetal evaluation. In the course of routine obstetric ultrasound, only about 15 percent of fetuses with heart disease are diagnosed. Fetal echocardiography is a targeted ultrasound evaluation of the fetal heart and vessels, as well as the umbilical vessels. This study is much more sensitive for the detection of fetal heart disease.

In the 13 years the Fetal Cardiology Clinic has been open, the largest change has been the great increase in the number of patients being referred to the clinic by area obstetricians. When fetal cardiac abnormalities are diagnosed prenatally, a team of physicians, nurses and social workers counsel the family on the significance of the heart problem. Prenatal diagnosis gives the family the time to prepare and familiarize themselves with their child's condition. The cardiologists set up an appropriate plan for treatment once the baby is born.

In the course of fetal evaluations every four to six weeks, the family receives counseling regarding the heart defect and plan for care. They meet with social workers for support, and meet nurses who will be involved in their child's care. They'll even tour the nursery and the PCCU where their child will be taken care of after birth and after surgery, if needed.

"This helps the family know what's in front of them and what they and their child will face after birth," said Ann Kavanaugh-McHugh, M.D., assistant professor of Pediatrics. "We can have everything ready when the baby is born. Children with heart disease may need medical therapy or surgical interventions after birth. We've taken one baby directly from the delivery right to the cath lab for a fixed balloon dilation of the septum. It was a life-saving procedure. If that child had been born in another hospital without prenatal diagnosis, she would've perished."

Some fetuses require treatment of diseases before birth. If a fetal arrhythmia is discovered, often the mother can be treated with oral medication, which can cross the placenta, until the baby is born. Diagnoses like these are very important for the baby, because some can become critically ill in utero if not treated.

"We're moving into an era when we are starting to intervene in fetal diseases," Kavanaugh-McHugh said. "With prenatal surgical interventions we may change the course of some congenital defects."

At the present time, the fetal echocardiographers are involved in monitoring fetuses undergoing fetal surgery at Vanderbilt, assuring that they remain stable from a heart standpoint during repair of myelomeningocele (the backbone and spinal canal do not close before birth), performed while they are still in their mother's uterus. No fetal cardiac surgical procedures are presently done at Vanderbilt. A small number of cardiac interventions have been performed at other centers, though the jury is still out on their efficacy. In the future, however, treatments such as balloon procedures for valve disease may be done prenatally.

"Fetal diagnosis is crucial to optimize the care we give patients now, and essential to advancing the care of children with heart disease in the future," Kavanaugh-McHugh said. VM