Pediatric Cardiac Catheterization

During catheterisation, the cardiologist enters a vein, an artery or both, usually at the top of the leg, and guides catheters into the heart chambers and great vessels under live X-ray, often supported by ultrasound. In a diagnostic study, the catheters measure pressures in each chamber, take small blood samples to check oxygen levels and inject contrast dye to outline the anatomy. These measurements answer questions that an echocardiogram or MRI cannot fully answer, such as the pressure in the lung arteries or whether a child is ready for the next stage of surgery. In an interventional procedure, the same route is used to treat the defect. A folded device can be carried to a hole between the upper chambers, an atrial septal defect, or into a patent ductus arteriosus, and opened to seal it. A balloon can be inflated across a narrowed pulmonary or aortic valve, called balloon valvuloplasty, or across a narrowed artery, sometimes leaving a stent in place.

Diagnostic catheterisation is recommended when scans leave important questions open, for example to measure lung pressures before heart surgery, to assess a single-ventricle circulation before the next staged operation, or to investigate pulmonary hypertension. Interventional catheterisation is recommended when a defect can be treated safely through a blood vessel rather than by open surgery. Typical examples are a secundum atrial septal defect of suitable size and position, a patent ductus arteriosus that persists after infancy or causes symptoms, a narrowed pulmonary valve, a narrowed aortic valve in selected babies and children, narrowed branch arteries to the lungs, and recurrent narrowing of the aorta after earlier repair. In some newborns, a catheter procedure creates or enlarges a passage between the upper chambers to improve oxygen levels. Adults with congenital heart disease also have catheter treatments, such as pulmonary valve replacement through a vein. The cardiology and surgical teams decide together.

Children usually receive general anaesthesia, so they are asleep and still throughout, while adults often need only local anaesthesia and sedation. The skin at the top of the leg is numbed, and a short tube called a sheath is placed into the vein or artery, through which catheters are passed to the heart under live X-ray. For device closure, the size of the hole is measured, often with an ultrasound probe in the food pipe or inside the heart, and a device of matching size is delivered folded inside a catheter, opened across the defect and checked before it is released. For balloon valvuloplasty, a balloon is positioned across the narrowed valve and briefly inflated to open it. Pressures are measured before and after to confirm the effect. At the end, the sheath is removed and pressure is applied to the groin until bleeding stops. Diagnostic studies may take about an hour, and interventions often one to three hours.

Before the procedure your child is assessed with an examination, an ECG, an echocardiogram and blood tests, and the team checks that the size and position of the defect and the rim of tissue around it suit a device or balloon. Very small babies, unusually large or awkwardly placed defects, or several defects together may be better treated by surgery. Your child will need to fast for several hours before anaesthesia, usually with clear fluids allowed until a set time, and any cold, fever or infection should be reported because the procedure may need to be postponed. Medicines are reviewed. Explaining the day to your child in simple words, bringing a favourite toy and planning for a parent to stay overnight all help. For international families, echocardiograms, MRI or CT images and earlier reports can usually be reviewed remotely, so the team can confirm whether a catheter approach is likely before you travel.

After the procedure, your child lies flat for a few hours so the groin puncture can seal, while nurses check the pulse in the leg, the wound and the heart rhythm. Most children eat and drink within hours and are walking by the next morning, and most go home after one night, once an echocardiogram confirms that any device is in position. Mild bruising and soreness at the groin are common and fade within days. Avoid baths, swimming, rough play and contact sports for about a week. After device closure, a medicine such as aspirin is often prescribed for several months while tissue grows over the device, and good dental care matters, because infection of a device is rare but serious. Plan to stay about 2 to 7 days, so a check-up is done before the flight. Take home the procedure report, the device details and a follow-up plan for your local cardiologist.

Pediatric cardiac catheterisation is an established procedure and serious complications are uncommon, but the risk varies with the child's age, size and condition and with the treatment performed. Possible problems include bleeding or bruising at the groin, reduced blood flow in the leg after artery access, which usually recovers with treatment, temporary heart rhythm disturbances, a reaction to contrast dye or anaesthesia and, rarely, damage to a heart wall or valve. After device closure, the device can occasionally move and need retrieval by catheter or surgery, and a small leak around it may persist and often closes over time. A balloon-widened valve may leak a little or narrow again, needing a repeat procedure later. X-ray doses are kept as low as possible. When the anatomy is suitable, device closure of an atrial septal defect or patent ductus arteriosus and balloon treatment of a narrowed pulmonary valve often give a lasting result without open-heart surgery.