Structural heart diseases are structural defects in the heart which may be present from the initial stages of birth, which need to be rectified by surgical interventions.
Transcatheter techniques applied for treating non-coronary heart diseases are known as structural heart interventions. New opportunities continue to unfold in the field of treating structural heart interventions. The Present day structural heart intervention training programmes include both valvular and non-valvular techniques concentrating on a wide range of adult primary congenital heart defects and complex surgical residual defects infant population. Many cardiologists prefer a new branch of percutaneous treatment which targets congenital and acquired diseases that were not addressed or were treated in another complex manner. Percutaneous structural heart interventions require a multi-axle approach involving cardiac imaging specialists, clinical cardiologists, interventional cardiologists, paediatricians and expert cardiac surgeons. A thorough assessment on patient procure compatibility has to be made. Continuous enhancement of knowledge and training in materials and devices to be used individual specific procedures is a prerequisite. The catheterization lab in the hospital must be equipped to perform hybrid procedures.
The following structural conditions are grouped together.
- Septal defects
- Valvular heart disease
- Vascular obstructions
- Any other conditions
They can further be grouped under the following categories:
- Defects involving the procedure of removal of an obstruction in the vascular channel of the valve using dilation with balloons or stents.
- Defects involving occlusion of an abnormal link between two cardiac chambers or vascular channels with closure coils or devices.
- Septal Heart defects:
Patent foreman ovale :
The origin of paradoxical embolism is PFO or patent foreman ovale and affects about one-quarter of the world’s population. In common parlance, it is just a hole in the heart. The foreman ovale is hole in the wall between the left and the right atria. The hole allows the blood to bypass the lungs of the foetus, which function on exposure to oxygen. When the foetus is brought out of the mother’s womb the baby starts breathing on his own. The hole closes in. In certain cases the hole remains open or patent, and is not a problem until the blood contains a clot in it. The clot may travel to the brain and cause a stroke. These conditions are basically treated with aspirin but in more risky cases a structural heart intervention may be adopted. Percutaneous closure or anti platelet therapy may be adopted from case to case basis.
Atrial Septal defect:
It is a congenital condition in which a hole in the wall between the upper chambers of the heart. ASD’s usually close on their own in early childhood, if they don’t then end up damaging the lungs or heart eventually. 3D echo or other imaging techniques help detect such abnormalities. A child with such defects, if unnoticed may have a short span of life as an adult. Percutaneous closure of the ASD is best indicated in patients with dilatated right chambers and good margins around the defect. Transesophageal echocardiography is done to ascertain the size, shape and location of the ASD. Percutaneous procedures are avoided with a very aneurysmatic septum or multi fenestrated defects in which there is an observed scarcity of surrounding tissue.
Interventricular Septal Defect :
The Ventricular structural defect is a gap or a hole in the wall separating the two lower chambers of the heart. In any normal child, it closes after the foetus is brought out. The hole if not closed leads to oxygen rich blood mixing with oxygen poor blood causing improper blood to be supplied to the body as the lungs become congested. Usually open heart surgeries are performed to close the gap. Percutaneous closure provides best results and a low complication rate.
Aneurysms of the Coronary Sinus and Ventricular Pseudoaneurysms
They are congenital heart diseases and are very rare in occurrence. These congenital defects usually affect the right sinus and non-coronary sinus which cannot be detected until and unless there is a rupture which touches the atrioventricular block. Aneurysms severe in nature may cause complications such as aortic regurgitation, subvalvular pulmonary stenosis or atrioventricular block.
If the valve is not terribly distorted and risky or severe regurgitation is not present, percutaneous closure can be the best alternative to surgery; traditionally surgical intervention is adopted to achieve better survival rates in patients. Ventricular pseudoaneurysm is a rare occurrence, but certain critical complications of myocardial infarction are treated by the surgical procedure. In recent trends of patients at high surgical risk, a success rate of a cent per cent has been achieved by using computed tomography angiography (CTA) and 3D TEE to successfully guide the procedure of surgical interventions.
Patent Ductus Arteriosus
It is a common congenital heart disease in children. The ductus arteriosus fails to close or remains patent or open and causes the irregular supply of blood between the pulmonary artery and the aorta. PDA may cause congestive heart failure. Prostaglandins are used to keep the DA open until the surgical intervention of the heart defect is completed. PDA is diagnosed through various non-invasive techniques such as chest X-ray, Doppler studies. PDA if untreated may lead to intraventricular haemorrhage or Eisen menger’s syndrome. Less severe PDAs can be closed by a percutaneous interventional method. A coil made of platinum can be deployed through the catheter passing through the femoral vein or artery which causes induction of coil embolization or thrombosis. A PDA occluder device comprising of nitinol mesh can be inserted from the pulmonary artery through the PDA. Surgical intervention is preferred in cases of severe PDA.
Coronary Fistula :
Coronary fistulae are asymptomatic in nature, but some children may show symptoms such as dyspepsia. Most lesions enlarge in progression and may warrant operative repair, either by transcatheter or surgical techniques based on the patient’s prognosis.
Pulmonary arteriovenous fistula :
It is a condition in which the blood vessels of the lung are abnormally formed; this is more prevalent in patients suffering from Rendu-Osler-Weber-disease. These patients often have abnormal blood vessels present in many parts of the body, including the lung. Minor fistulas may be treated through embolization, major fistulas require surgery.
Coarctation of the Aorta : COA or coarctation of the aorta is a congenital heart condition in which the aorta narrows or contracts in the area where the ductus arteriosus (ligamentum arteriosum after regression) inserts. It is common in kids who have Turner syndrome. Symptoms include poor appetite, difficulty in breathing, cold legs or feet. An MRI of the chest will reveal the location of the coarctation of the aorta and determines whether it affects other blood vessels in the body. Cardiac catheterization is an interventional procedure that opens up the coronary artery to increase the blood flow to the heart. In certain cases angioplasty can be performed to dilate the narrowed artery.
Stenosis of the Pulmonary Arteries and Veins :
Stenosis means narrowing of pulmonary artery or veins. Oxygen supply through the blood to lungs is severely disrupted leading to damage of the heart muscle. Stenosis of the pulmonary artery or vein may be accompanied with tetralogy of fallot, pulmonary atresia, truncus arteriosus, pulmonary valve stenosis, and patent ductus arteriosus. Interventions to correct the same include balloon dilation method, with or without stent placement.
Other structural interventions include the closure of atrial appendage to correct the problem of atrial fibrillation which a common form of arrhythmia or post surgery paravalvular leaks.
Structural heart disease interventions cover a wide range of procedures for treating congenital and acquired complications and the mortality rates have been reduced considerably.
KIMS and Structural Heart Interventions :
KIMS has established itself of the best hospitals in South India and has its branches expanding to the remote towns in Andhra and Telangana in pursuit of providing expert medical care. Our state of the art Heart Centre is one in its kind in India catering to heart ailments. Our interventional cardiologists are a team par excellence in providing the best individualised medical care with a personal touch. KIMS is the first hospital in AP & Telangana to have a Green OT. Our cardiologists have handled critical interventions with outmost precision and accuracy and achieved positive results with excellent outcomes.