The Heart Center - Arkansas Children's Hospital

Michiaki Imamura, M.D., Ph.D.; Pediatric Cardiac Surgeon, Arkansas Children's Hospital; Assistant Professor of Surgery, University of Arkansas for Medical Sciences

Definition

Our hearts have four chambers inside (Figure 1). Under normal conditions, the blood from the body comes back to the heart into the right atrium (RA). This blood is relatively blue (deoxygenated blood). This blue blood goes to the right ventricle (RV), which pumps the blood to the lungs through the pulmonary artery (PA). In the lungs, the blood becomes red (oxygenated blood) and returns to left atrium (LA) through the pulmonary veins (PVs) and then to the left ventricle (LV). The LV pumps this red blood to the whole body through the aorta. There are four pulmonary veins (two on each side).

Figure 1

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In patients with Total Anomalous Pulmonary Venous Return (TAPVR), all four pulmonary veins do not connect normally to the left atrium, but instead drain abnormally to the right atrium by way of an abnormal (anomalous) connection.

Some patients with heterotaxy syndrome have TAPVR in addition to the other complex cardiac conditions such as single ventricle, pulmonary stenosis, pulmonary atresia or common atrioventricular valve. In this section this kind of complex patient is not discussed.

Classification

TAPVR is classified into four different types, based on the location of the abnormal pulmonary vein connection:

A. Supracardiac type (Figure 2) - The pulmonary drain to the right atrium through the supervior vena cava (SVC). The pulmonary veins come together behind the heart and then drain upward to an abnormal vertical vein. This vein joins the innominate vein which connects to the right superior vena cava and drains to the right atrium or joins the right superior vena cava directly.

B.Cardiac type (Figure 3) – The pulmonary veins come together behind the heart and then drain to the right atrium usually through the coronary sinus. The coronary sinus is the vein that normally returns blood from the heart muscle itself back to the right atrium after its oxygen has been depleted. The coronary sinus drains directly into the right atrium. Rarely, the pulmonary veins come together and drain into the right atrium not through the coronary sinus.

C. Infracardiac type (Figure 4) – The pulmonary veins drain to the right atrium through the hepatic (liver) veins or inferior vena cava (IVC). In this type, the pulmonary veins join together behind the heart and then drain downward, connecting to the liver’s portal vein system. They then drain through the vascular bed of the liver and enter the right atrium through the hepatic veins.

D. Mixed type (Figure 5) – This is a mixture of the above mentioned three types of TAPVR. In this type of patient, some pulmonary veins are returning through one of the above mentioned types and other pulmonary veins are returning through other pathways. All surviving patients with TAPVR have an atrial septal defect. The left side of the heart gets blood through this atrial septal defect. Decreased oxygen content of the systemic blood, an increased volume load to the right ventricle, and increased right ventricular systolic pressure characterize the physiology of TAPVR.

Newborns with TAPVR and obstructed pulmonary venous return get extremely sick soon after birth because of severe desaturation and congestion of the lungs. These patients may be thought to have severe lung disease at this stage. Historically, these children are diagnosed with severe pulmonary hypertension and treated.

When obstruction to pulmonary venous return is not present or minimal, children with TAPVR may be asymptomatic. There may be mild labored breathing. There is often cyanosis, but it may be mild and difficult to identify. These patients may be diagnosed at several months or years old.

Total Anomalous Pulmonary Venous Return Evaluations and Diagnosis

On physical examination, there are no typical signs except heart murmur and desaturation. However, desaturation is not often severe and heart murmur is not prominent.

A chest X-ray, similarly, will show heart enlargement and also will demonstrate increased pulmonary artery blood flow. In patients with TAPVR and obstructed pulmonary venous return, chest X-ray shows evidence of pulmonary edema.
Echocardiography usually makes a definitive diagnosis of TAPVR. This study will demonstrate no connection between the pulmonary vein and the left atrium. The abnormal connection and pathway of the pulmonary veins to the systemic circulation can be visualized. Echocardiography can evaluate the right atrial and right ventricular dilatation, the size of and flow across the atrial septal defect, and pressure of the right ventricle.

Occasionally, cardiac catheterization is required to make a definite diagnosis of TAPVR. Cardiac catheterization will define the abnormal connection of all pulmonary veins, and is particularly helpful in patients with mixed type of TAPVR.

Treatments

TAPVR is a cardiac defect which requires surgical correction. The timing of the repair varies depending on the type of TAPVR present, and the symptoms of the child. Generally, surgery should be scheduled after diagnosis at an early time. Surgical repair is performed emergently in the newborn period for patients with TAPVR and obstructed pulmonary veins. Children with TAPVR without obstruction to pulmonary vein return undergo surgical repair electively.

In the supra- or infra-cardiac types of TAPVR, the common confluence of pulmonary veins is anastomosed to the left atrium, and the atrial septal defect is closed. In the cardiac type of TAPVR, the common confluence or the coronary sinus is un-roofed and an atrial septal defect is closed usually with a patch. In the mixed type of TAPVR, the larger part of the pulmonary vein is anastomosed to the left atrium, and the smaller part of the pulmonary vein may be left to be drained to the right side of the heart.

Treatment Results

The surgical results for TAPVR generally are excellent in the current era. When surgery is performed electively without obstructed pulmonary veins, the mortality rate is less than 5 percent. The long-term outcome after TAPVR repair is generally well. The surgical mortality is significantly higher when surgery is performed emergently in critically ill newborns with obstructed pulmonary venous return. After TAPVR repair, patients occasionally require re-operation due to pulmonary vein stenosis or residual atrial septal defect. Pulmonary vein stenosis can develop at the site of surgical repair or at the pulmonary veins themselves.

Charles E. Johnson, R.N., C.C.P., Director of Cardiovascular Operating Room,Extracorporeal Membrane Oxygenation (ECMO) and Perfusion, Arkansas Children's Hospital

Sherry C. Faulkner, C.C.P., Clinical Cardiovascular Perfusionist, Arkansas Children's Hospital

Introduction
Blunt chest trauma in children is a common occurrence but rarely requires surgery. When severe enough, the lungs, heart and/or intra-thoracic vessels can be damaged and the injury result in death. Myocardial contusion may cause myocardial infarction with ventricular arrhythmias or pericardial tamponade. Blunt chest trauma severe enough to cause an isolated inter-ventricular septal defect is an even rarer occurrence.

Case Report
A 15-year-old male patient was attempting to ride a 2,000-pound bull. The adolescent, who was not wearing protective head or chest gear, was thrown to the ground and stomped repeatedly. He presented to the emergency room of an outlying hospital with complaints of chest pain and respiratory distress. On examination, there were large bruises (hoof-shaped) over the right quadrant of the abdomen and the mid-sternal area. He was diagnosed with a loud heart murmur, pulmonary contusion and splenic fracture. Systolic blood pressure was initially 80-90 mmHg. The adolescent was treated with intravenous fluids and a dopamine infusion, then immediately airlifted to our facility for further evaluation and treatment.

Upon arrival, the patient was conscious but had no recollection of the accident. Chest roentgenogram showed cardiomegaly with moderate pulmonary edema. Electrocardiogram demonstrated sinus tachycardia and premature ventricular contractions with some coupling. Echocardiogram showed a large ventricular septal defect. Computed tomography scan of the chest did not reveal any anatomic abnormalities. The patient was bloused with a loading dose of lidocaine and a lidocaine infusion started in addition to dobutamine and milrinone infusions. He was then transferred to the Cardiovascular Intensive Care Unit (CVICU) for monitoring and to allow the heart defect to partially fibrose as scar tissue. This scar tissue will be useful for securing the patch material during the closure of the ventricular septal defect.

On day No. 2, the patient was electively intubated to provide positive pressure treatment of the pulmonary contusion. The patient remained hemodynamically stable until day No. 6, when he acutely deteriorated. During cardiac catheterization, significant left atrial hypertension and a right-to-left shunt ratio in excess of 3:1 was found. A swan-ganz catheter was placed, and the patient was immediately taken to the operating room.

In the operating room, monitoring lines were placed in the left groin and by means of a Seldinger technique an intra-aortic balloon pump (IABP) was placed. The IABP was set at 1:1 and the after load reduction stabilized the hemodynamics. Inotropes were weaned and the patient was given cardio protective drugs including corticoids, a lidocaine bolus, and a dose of allopurinal prior to the median sternotomy. Isoflorane as part of the general anesthetic to allow myocardial preconditioning (heat shock gene induction).

During the median sternotomy it was discovered that the sternum was fractured across the midline at the point of impact from the bull’s hoof. There was a hematoma beneath the sternum and the pericardium was densely adhered to the back of the sternum. The left and right pleural spaces were opened and large bilateral pleural effusions totaling 800cc’s were evacuated. The pericardium was opened to the left of midline and a large pericardial effusion was evacuated. The patient was cannulated in a routine fashion and full cardiopulmonary bypass (CPB) established. The patient was cooled to 27º C. The aorta was cross-clamped and cold crystalloid cardioplegia was administered. The position of the left anterior descending coronary was carefully noted. A wet pack was placed behind the heart, which allowed elevation of the heart and exposure of the apex. The area surrounding the LAD had been significantly damaged and evidence of ischemia was apparent. Additionally, the right ventricular free wall was excessively dimpled and thinned, presumably at the area of direct impact with the bull’s hoof.

The left ventricle was opened and the defect was noted to extend from the base of the papillary muscle to the anterior free wall of the septum. The defect measured 3 cm x 6 cm with an oval shape. The areas of necrosis were clearly seen, and it was noted little viable tissue was present to anchor the patch material. A Hemashield® patch was used to close the defect. The edge of the patch was allowed to protrude through the ventriculotomy and a Teflon felt patch was sewn to either edge of the ventriculotomy. This was then closed as a composite graft. The patient was warmed in routine fashion. The cross clamp was removed and the patient allowed to de-air passively through the root of the ascending aorta. The patient was rested on CPB for a period of 25 minutes after completion of the procedure and then weaned from CPB. A transesphogeal echocardiogram was performed which showed a complete repair of the VSD. The mean pulmonary artery pressure was decreased from 30 to 15 mmHg and the wedge pressure decreased from 20 to 11 mmHg. Total CPB time was 110 minutes with a cross clamp time of 65 minutes. After administration of protamine and satisfactory hemostasis, the chest was closed and the patient transported to the CVICU in stable condition. The IABP assistance was continued at a rate of 1:1. The patient was maintained on dopamine 3 mcg/kg/minute, dobutamine 5 mcg/kg/minute, and milrinone 0.5 mcg/kg/minute.

The IABP was removed on post-operative day No. 2. The patient continued to do well hemodynamically and was extubated on post-operative day No. 4 and discharged home on post-operative day No. 12.

Discussion
Published literature describes most blunt chest trauma as usually associated with impact distributed over larger areas of the thorax, such as might occur from a steering wheel impact or a fall in a bathtub. However, small areas of blunt trauma such as a hoof of a bull can cause isolated and yet more extensive organ injury due to the greater force per area of impact. As seen by this patient’s pre-operative findings, the extent of organ damage may be difficult to predict. Timing of surgery is critical to ensure optimal results of repair. Intense management of the patient’s pre-operative course with the goal of allowing organs to begin to recover must be balanced with indications of life-threatening and imminent deterioration. Changes in the patient’s hemodynamics warrant immediate investigation and consideration of aggressive surgical intervention.

Immediate recognition of myocardial trauma and rapid transport to a pediatric cardiac center contributed to the superlative outcome for this adolescent.

The UAMS Pediatric Cardiology Fellowship based at Arkansas Children’s Hospital was accredited by the American College of Graduate Medical Education (ACGME) in May and began operations on July 1, 2007. The fellowship is a three-year program designed to train pediatricians to become academic pediatric cardiologists. Our program is approved for two fellows per year. The intent of the pediatric cardiology training program is to develop academic physicians well trained and able to practice in a competent and independent fashion as pediatric cardiologists. This training is achieved through supervised clinical work with increasing responsibility for outpatients and inpatients, supervised experience in non-invasive and invasive cardiology and a structured and mentored research experience with a minimum of 12 months of protected research time. Upon completion of the program, the fellows will be eligible for certification by the American Board of Pediatrics, sub-board of Pediatric Cardiology.

The three-year training program is based primarily at Arkansas Children’s Hospital but fellows will rotate to an Adult Congenital Heart Clinic at Heart Clinic Arkansas and general cardiology regional clinics throughout the state. The fellows will have opportunities for research provided at Arkansas Children’s Hospital and UAMS. The first 18 months of the curriculum at ACH is clinical with rotations in the heart station, cardiac catheterization laboratory, in-patient ward service, cardiovascular ICU, consultation service and outpatient clinics. The subsequent 12 months is set aside for research time and the last 6 months are selectives or continued research time.

About our fellows:

Dr. Rahel Zubairi

Dr. Chandra Srinivasan

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Our inaugural fellow is Dr. Rahel Zubairi. He received his M.D. in 1999 from Thomas Jefferson Medical College in Philadelphia, Penn. and completed a residency in internal medicine and pediatrics at Albert Einstein Medical Center, also in Philadelphia. He was chief medical resident at Thomas Jefferson University Hospital, Frankford Healthcare System in Philadelphia, Pen. from 2003-2004. Dr. Zubairi worked as a faculty member at Georgetown Medical Center in Washington, D.C. and at ACH before beginning his fellowship in July 2007. Dr. Zubairi and his wife Sadia, a dentist, have been married six years and have two children, Hanna and Noah.

Our program recently accepted Dr. Chandra Srinivasan as a visiting fellow from the University of Chicago. He arrived on August 27, 2007 and will complete the remainder of his first year here at ACH. Our plan is to transfer Dr. Srinivasan to the pediatric cardiology fellowship at UAMS in July of 2008. Dr. Srinivasan received his MBBS in 1999 from the University of Kerala in Kerala, India. He received training in pediatrics from the Postgraduate Institute of Medical Education and Research in Chandigarh, India and completed a residency in pediatrics at New York University Medical Center. Dr. Srinivasan and his wife, Dr. Krithika Lingappan, have been married three years.

What is your role at ACH, and how long have you worked here? I am a patient care partner. I have been a proud employee of ACH for just over one year.

Why is your job rewarding?
Honestly, I cannot begin to list all of the reasons I love my job. I enjoy working with children of all ages and being able to aid in improving their quality of life, which brings me great satisfaction. Also as a PCP, I have obtained an immense amount of invaluable knowledge that I will be able to carry into my career as a registered nurse.

How did you become interested in pediatric cardiology or cardiovascular surgery? I love children, and I want to become a nurse. Before coming to ACH, I wanted to ensure that the nursing field was right for me, so I applied for the PCT position in the CVICU. Shortly after I began working in the CVICU, I knew this unit was the place for me.

What do you want people to know about the Heart Center at Arkansas Children’s
Hospital?
Personally, I view the CVICU at ACH as one of the best. I have drawn this conclusion through not only my experiences, but also through the testimonies of patients and families. We have a great team here in the Heart Center. The main thing I would say to anyone is WE CARE. We try to the best of our ability to care properly for our patients, and we are continually improving.

What do you enjoy most about working with children?
I’ve always loved working with children. Working at ACH gave me the chance to work with children and pursue my career. I love making children smile. The children obviously would choose to be elsewhere rather than the ICU, so I love to try and make their stays a little better by talking with them, singing, playing or just holding them. Easing their fears and putting smiles on their faces make coming to work worth it all!

What has been your most memorable moment working in the Heart Center at Arkansas Children’s Hospital?
I have so many memories from only one year, but one of my favorite memories was when a patient was missing her mother. She would cry and call for her mother who worked late. I went in her room, put her in my lap, and sang “This Little Light of Mine” for 20 minutes straight until she fell asleep. From then on when I saw her she would ask me to sing “Light of Mine,” as she called it.

What is your greatest professional achievement?
Simply being able to be a part of the Heart Center Team is a great achievemnet in my eyes. I know that my position is very important in providing adequate, safe care for our patients. Knowing that I try my best in providing such care is an achievement in itself.

Definition