Pediatric Cardiac Catheterization: Procedure, Uses, Risks and Recovery

Cardiac catheterization in children is a minimally invasive, non-surgical medical procedure used to diagnose and treat congenital or acquired heart conditions by reaching the heart directly through the blood vessels with very thin, flexible tubes. Thanks to these minimally invasive interventional cardiac techniques, which are performed without opening the chest, procedures such as closing holes in the heart, widening narrowed blood vessels, and repairing malfunctioning heart valves can be carried out much more comfortably than with open-heart surgery. Performed under the guidance of high-resolution medical imaging systems, these closed procedures accelerate the recovery process for young patients, allowing them to return quickly to a normal and healthy life without any surgical scars on the chest.

What Is Cardiac Catheterization in Children and for What Purposes Is It Performed?

Cardiac catheterization in children is a procedure that uses long, extremely flexible, soft, and specially manufactured medical plastic tubes with diameters measured in millimeters, about the thickness of spaghetti. These tubes are called catheters. A small needle is usually inserted into a large artery or vein in the child’s groin, and sometimes in the neck or arm. The thin tube placed inside the blood vessel is then gently advanced along the direction of blood flow until it reaches the chambers of the heart and the major blood vessels leaving the heart.

In previous years, this method was used only to understand what was happening inside the heart, measure pressures, and obtain X-ray images of the heart—that is, solely to establish a diagnosis. However, in modern medicine, the greatest strength of this method lies in its therapeutic capabilities. Today, by sending umbrella-like devices through these thin tubes, we can completely close holes in the heart, or reach narrowed heart valves with balloon-tipped catheters and inflate the balloon to relieve the narrowing. The laboratories where these procedures are performed are highly advanced centers equipped with massive display screens, high-tech X-ray systems capable of providing real-time three-dimensional imaging, and monitors that track every vital sign second by second.

Each of these procedures requires extraordinary precision because children’s hearts and blood vessels are much more delicate and fragile than those of adults. For this reason, the specialists performing these procedures complete many years of general pediatric training, followed by years of specialization in cardiac anatomy and diseases, and then undergo additional advanced training specifically for these intravascular interventions.

What Preparations Are Made at the Hospital Before Cardiac Catheterization in Children?

Except in emergencies, when families come to the hospital for a scheduled procedure, the key to success lies in an extremely meticulous and detailed preparation process. It is entirely natural for families to feel great anxiety and excitement at this stage. The thought of someone working on their child’s heart is frightening for every parent. Therefore, preparation involves much more than medical testing; it also includes reassuring the family psychologically, explaining every stage of the process transparently, and helping the child feel safe in the hospital environment.

On the day of the procedure or the day before, the child undergoes a comprehensive physical examination. Heart sounds are listened to, lung sounds are checked, and the child’s overall health is evaluated. Next, an electrocardiogram (ECG) is performed using small adhesive electrodes placed on the chest to record the electrical activity of the heart. Afterwards, echocardiography (heart ultrasound) is performed using sound waves transmitted through a cool, transparent gel applied to the chest. This examination provides real-time images of the inside of the heart, valve movements, and blood flow, helping to define the procedural roadmap.

Because children must be put to sleep during the procedure, having an empty stomach is a critical safety requirement. Food or liquids in the stomach create the risk of aspiration into the lungs during anesthesia. Therefore, the child must not eat anything and must avoid all liquids, including water, for at least six hours before the scheduled procedure. Although managing this fasting period can be difficult in infants, this rule must never be compromised for safety reasons.

Some laboratory tests required before the procedure include:

• Complete blood count
• Coagulation tests
• Kidney function tests
• Blood type determination
• Infection markers

Will Children Feel Pain During Cardiac Catheterization?

This is one of the questions that families fear the most and are most eager to have answered. While navigating the finest curves of the heart with millimetric precision, even the slightest movement, pain, fear, or crying from the child is completely undesirable. Such reactions may jeopardize the success of the procedure and also create deep psychological trauma for the child. Therefore, ensuring the child’s comfort and maintaining a completely pain-free experience are the highest priorities throughout the procedure.

Different sedation and anesthesia methods are selected according to the child’s age, weight, psychological condition, and the complexity of the planned procedure. In most cases, a mild sedative syrup is given before entering the procedure room to help the child relax and reduce fear of the hospital. Once on the procedure table, a special numbing cream is applied to the groin or neck where the catheter will be inserted, or the area is completely numbed with a small injection of local anesthetic.

The child is then placed into a deep and comfortable sleep with medications administered through an intravenous line. In very young infants, highly active children, or particularly complex and lengthy procedures, general anesthesia is used, meaning the child is completely asleep under the supervision of an anesthesiologist while breathing is supported by a machine. Regardless of the technique used, the child feels none of the procedure, experiences no pain, and usually remembers nothing afterwards, awakening as though from a long and pleasant dream.

In Which Situations Should Cardiac Catheterization in Children Be Postponed?

No matter how safe cardiac procedures have become, they are still invasive interventions involving one of the body’s most vital organs. Therefore, the child’s body should be in optimal health before undergoing the procedure. If the procedure is elective and the child’s current condition increases the risk, it is postponed without hesitation.

For example, a special medical dye (contrast agent) is injected into the bloodstream during the procedure to make the heart’s blood vessels visible on X-ray imaging. After the procedure, this dye is filtered by the kidneys and eliminated in the urine. If the child already has significant kidney dysfunction, this concentrated substance may further impair kidney function. Likewise, if there is an active or hidden infection in the body, bacteria circulating in the bloodstream may reach the heart through the blood vessels and cause a destructive infection.

The main conditions requiring postponement or cancellation of the procedure include:

• Active respiratory tract infection
• Persistent high fever
• Severe kidney failure
• Uncontrolled bleeding disorders
• Severe anemia
• Contrast agent allergy

Why Does Cardiac Catheterization in Children Require Special Attention in Infants With Genetic Syndromes?

Children born with certain genetic differences may respond very differently from standard expectations in terms of physiology and anatomy. This requires significantly greater attention and completely individualized strategies in the catheterization laboratory.

For example, children with the genetic condition known as DiGeorge syndrome may have underdeveloped glands responsible for regulating calcium balance in the body. Their blood calcium levels are already prone to becoming dangerously low. If the child breathes rapidly during the procedure, changes in the acid-base balance may suddenly trigger severe muscle spasms. In addition, if these children require a blood transfusion during the procedure, the preservatives contained in standard blood products may bind calcium in the bloodstream and potentially cause life-threatening events, including cardiac arrest. Therefore, only specially processed, irradiated blood products may be administered.

Children with Down syndrome have blood vessels that are much more sensitive to catheter manipulation. When a foreign object enters the blood vessel, the risk of clot formation and vascular blockage is significantly higher than in other children. Teams familiar with this fact administer more intensive anticoagulation during the procedure and monitor the groin artery much more carefully and for a longer period afterwards.

How Are Diagnosis and Imaging Performed During Cardiac Catheterization in Children?

Sometimes ultrasound imaging performed from outside the body is not sufficient to fully understand the architecture of the heart. It may be necessary to measure the pressure inside each chamber of the heart with millimetric precision and determine the oxygen saturation of the blood directly within the heart. During diagnostic catheterization, the thin catheter is advanced step by step into the right atrium, the right ventricle, and then into the pulmonary arteries. Wherever the catheter tip is located, pressure waveforms from that chamber immediately appear on the monitors. At the same time, blood samples are collected through the catheter to identify where oxygen-rich and oxygen-poor blood are mixing inside the heart.

For imaging, angiography is performed. A special contrast agent that blocks X-rays is rapidly injected into the heart through the catheter. At that exact moment, large X-ray cameras rotating around the child capture dozens of images per second, creating a high-resolution video. This video clearly demonstrates how the contrast spreads within the heart, struggles to pass through a narrowed valve, or leaks through an abnormal opening into another chamber. If open-heart surgery becomes necessary later, this provides cardiac surgeons with a precise, real-time map of the internal anatomy.

How Are Emergency Interventions Performed in Cyanotic Infants Using Cardiac Catheterization?

Some infants are born with a major disadvantage. Due to severe structural defects of the heart, oxygen-rich blood returning from the lungs cannot be distributed to the body. Instead, oxygen-poor blood returning from the body is pumped back into the circulation. These babies are born with dark bluish discoloration of the lips, fingertips, and skin. If a pathway allowing oxygen-rich and oxygen-poor blood to mix cannot be created within the heart, survival becomes impossible.

This is where the life-saving emergency catheter procedure known as Balloon Atrial Septostomy (Rashkind procedure) comes into play. A catheter is introduced through the groin or umbilical vein into the upper right chamber of the heart. A thin membrane naturally exists between the right and left atria. A balloon-tipped catheter is advanced through this membrane into the left atrium. Once inside, the balloon is rapidly inflated and then pulled forcefully back into the right atrium. This tears the membrane and creates a large opening between the two chambers. Through this opening, oxygen-rich blood from the lungs and oxygen-poor blood from the body can mix, allowing at least some oxygen to reach the infant’s tissues. The baby’s color often improves within minutes. Although this procedure does not cure the underlying condition, it buys invaluable time until definitive corrective heart surgery can be performed.

The anatomical conditions requiring emergency atrial septostomy include:

• Transposition of the great arteries
• Tricuspid atresia
• Mitral atresia
• Hypoplastic left heart syndrome

How Are Narrowed Heart Valves Opened With Cardiac Catheterization in Children?

The heart valves function like double-sided doors that allow blood to flow in only one direction. They open fully while blood is pumped through them and close tightly afterwards to prevent backflow. However, some children are born with these “doors” having thickened, fused, and narrowed hinges. The heart must work much harder than normal to force blood through this narrow opening. Over time, this excessive workload causes the heart muscle to become abnormally thickened and eventually weakened.

To relieve these narrowings, a technique called balloon valvuloplasty is used. The procedure begins by positioning a specially selected deflated balloon, sized precisely to fit the narrowed valve, at the level of the fused valve. Once the balloon is confirmed to be perfectly centered within the valve, it is gradually inflated with pressurized fluid. As it expands, the balloon pushes the fused valve leaflets apart and tears the fused areas, allowing the valve to open widely. Inflation usually lasts only ten to fifteen seconds, depending on the valve. The balloon is then immediately deflated and removed. As soon as the obstruction is relieved, the tremendous workload placed on the heart disappears within seconds, allowing the heart to function much more efficiently.

The degrees of valve narrowing are classified as:

• Mild stenosis
• Moderate stenosis
• Severe stenosis
• Critical stenosis

How Are Heart Defects Closed Without Surgery Using Cardiac Catheterization in Children?

One of the most remarkable fields of pediatric cardiology is the closure of defects in the wall dividing the right and left sides of the heart. Through these defects, oxygen-rich blood continuously passes into the oxygen-poor side, sending excessive blood to the lungs. Over time, the pulmonary blood vessels may become permanently damaged due to this increased pressure.

Today, most of these defects can be treated without opening the chest. Special devices made from a shape-memory metal called nitinol are folded into a long, narrow shape and inserted through the catheter. Once advanced to the site of the defect, they are gradually released from the catheter. As soon as they emerge, the device instantly returns to its original shape due to the metal’s memory and body temperature, opening like two umbrellas on either side of the defect and securely sandwiching it between them. After echocardiography confirms perfect positioning, the device is detached from the delivery wire, completing the procedure. Over the following months, the heart’s inner lining gradually grows over the metal device, making it a permanent part of the heart. There is no scar on the chest, and the child usually goes home walking the next day.

The heart defects most commonly closed by catheter techniques include:

• Atrial septal defect
• Ventricular septal defect
• Patent ductus arteriosus
• Abnormal vascular connections

How Does Hospital Follow-up Progress After Cardiac Catheterization in Children?

Once the procedure has been successfully completed and the catheter has been removed, another highly important stage begins. As soon as the catheter is withdrawn from the artery or vein in the groin, there is a high risk of bleeding because of the pressure inside the blood vessel. Therefore, the physician or nurse immediately applies firm manual pressure over the site. This continuous pressure is maintained for approximately twenty minutes while the body forms a strong natural clot to seal the vessel. Once bleeding has completely stopped, the area is wrapped with a tight, thick bandage, and a small sandbag is usually placed on top to maintain pressure.

During the first four to six hours after returning to bed, the child must remain lying flat on the back and must not bend the leg used for the procedure. Bending the leg may dislodge the newly formed clot and allow blood to leak beneath the skin, resulting in a large and painful hematoma. Since it is difficult for a young child to remain still for several hours, the residual drowsiness from the procedure together with the family’s support makes this period easier. In addition, to help eliminate the contrast dye used during the procedure, which places stress on the kidneys, the child is encouraged to drink plenty of fluids such as water or apple juice as soon as awake. If nausea is present, fluids are administered intravenously.

The vital signs regularly monitored by nurses during the first twenty-four hours include:

• Heart rhythm
• Blood pressure
• Oxygen saturation
• Groin pulse
• Toe temperature
• Toe color

What Should Be Considered During Home Care After Cardiac Catheterization in Children?

If the final ultrasound performed the next day confirms that everything is satisfactory, the implanted device (if one was used) has not moved even a millimeter, there is no fluid around the heart, and the groin vessel remains intact, the family is discharged after receiving detailed home care instructions. Parents usually experience great relief when they return home with their child.

The most important consideration at home is preventing dangerous blood clot formation on the implanted device until it becomes completely covered by the heart’s own tissue over the following months. For this reason, the low-dose blood-thinning medication prescribed by the physician (such as baby aspirin) must be given every day at the same time without interruption. In addition, during the first month, activities that place strain on the chest, carrying heavy backpacks, and contact or strenuous sports should be avoided to prevent unnecessary stress on the heart and movement of the device.

The following emergency warning signs after discharge require immediate medical attention:

• Persistent high fever
• Difficulty breathing
• Severe chest pain
• Bluish discoloration of the treated leg
• Coldness in the treated leg
• Sudden body swelling due to fluid retention

What Are the Possible Risks of Cardiac Catheterization in Children?

No medical procedure is completely risk-free. Especially when dealing with the tiny blood vessels and delicate tissues of children, even the simplest intervention carries potential risks. However, cardiac catheterization laboratories are staffed by highly experienced teams equipped with extraordinary technology and crisis management expertise, enabling them to respond to even the smallest complication within seconds.

The most common problems usually involve the vascular access site in the groin. The relatively large introducer sheaths inserted into the blood vessel may damage the inner wall of the artery or trigger clot formation leading to vessel blockage (thrombosis), particularly in very small infants with low body weight. If the pulse in the leg disappears, powerful anticoagulant or clot-dissolving medications are started immediately to reopen the vessel. While inside the heart, the catheter tip may occasionally touch the heart muscle, temporarily disturbing the electrical conduction system and causing rhythm disturbances. These situations generally resolve immediately when the catheter is withdrawn slightly.

Throughout the entire process, the most important fact families should know is that, in the eyes of the experienced team in that room, their child’s heart is the most precious responsibility in the world. Every movement, every medication dose, and every decision is calculated with years of scientific experience and deep compassion.

Although rare, complications that may occur during interventional procedures include:

• Blood clot formation in the groin vessel
• Bleeding beneath the skin
• Heart rhythm disturbances
• Fluid accumulation around the heart
• Slowed breathing
• Injury to the blood vessel wall

Frequently Asked Questions

Prof. Dr. İbrahim Cansaran TANIDIR

Prof. Dr. İbrahim Cansaran Tanıdır is an internationally recognized specialist with nearly 20 years of clinical, academic, and interventional experience in the fields of congenital heart diseases, pediatric interventional cardiology, hybrid procedures, and radiation-reduced / fluoroscopy-free catheterization techniques.

To date, he has performed more than 10,000 pediatric cardiac catheterization procedures both in Turkey and abroad, and has pioneered advanced interventional and hybrid applications in complex structural heart diseases in our country.

His academic productivity represents a scientifically strong authority with 110 SCI/SCIE publications, 1,440 citations, and an H-index of 18 (Google Scholar, 2025).