Congenital heart diseases
Congenital heart diseases
NORMAL HEART (for comparison)
Blood that has travelled through the body enters the right atrium via the vena cava superior and inferior. It then travels to the right ventricle, passing the tricuspid valve. It is then pumped into the pulmonary trunk (passing the pulmonary valve), that divides into left and right pulmonary arteries, towards the lungs. In the lungs, oxygen is bound to the blood; it becomes oxygen-rich. Subsequently, the oxygen-rich blood enters the left atrium. Passing the mitral valve, the blood enters the left ventricle. The left ventricle pumps the blood into the aorta (passing the aortic valve), upon which it travels to all the organs and tissues in the body, providing them from oxygen. Once it has done so, it travels back to the right atrium.
The model depicts blood flow through the heart. It shows how deoxygenated blood enters the right atrium (blue arrows), travels through the right ventricle and is pumped to the lungs, where it becomes oxygenated. Then, it travels through the pulmonary veins into the left atrium (pink arrows), goes through the left ventricle and is pumped into the aorta, from where it will travel to all corners of the body, to supply tissues with oxygen.
CYANOTIC CONGENITAL HEART DISEASES
This model shows the tetralogy of Fallot. Two windows were made to enable a view inside the heart; one in the right ventricle and one in the left ventricle. Tetralogy of Fallot is is a congenital heart defect (a problem considering the structure of the heart that is present by birth). It involves four heart defects: - A large ventricular septal defect (VSD) - Pulmonary stenosis - Right ventricular hypertrophy - An overriding aorta.
This model shows a parasternal long axis echo plane of a heart with the tetralogy of Fallot.
Tetralogy of Fallot is is a congenital heart defect (a problem considering the structure of the heart that is present by birth). It involves four heart defects: - A large ventricular septal defect (VSD) - Pulmonary stenosis - Right ventricular hypertrophy - An overriding aorta.
This model shows atresia of the tricuspid valve. The tricuspid valve, usually situated between the right atrium and the right ventricle, was not constructed. Because of this, there is a decreased blood flow, which has resulted in the suboptimal development of the right ventricle. Hence the small (hypoplastic) right ventricle. Since the right ventricle cannot pump the blood into the lungs, the blood has to get there in a different way. This is accomplished by surgery: the Fontan procedure. The surgeon attaches all vessels that usually go to the right atrium directly to the lungs. Those vessels contain oxygen-poor blood from the upper body (superior caval vein) and lower body (inferior caval vein) and are attached directly to the lungs via a tunnel, the Fontan tunnel. Oxygen is bound to the blood cells in the lungs. This oxygen-rich blood then enters the left atrium, the right ventricle and is pumped by the left ventricle into the body.
This model shows atresia of the tricuspid valve. The tricuspid valve, usually situated between the right atrium and the right ventricle, was not constructed. Because of this, there is a decreased blood flow, which has resulted in the suboptimal development of the right ventricle. Hence the small (hypoplastic) right ventricle. Since the right ventricle cannot pump the blood into the lungs, the blood has to get there in a different way. This is accomplished by surgery: the Fontan procedure. The surgeon attaches all vessels that usually go to the right atrium directly to the lungs. Those vessels contain oxygen-poor blood form the upper body (superior caval vein) and lower body (inferior caval vein) and are attached directly to the lungs via a tunnel, the Fontan tunnel. Oxygen is bound to the blood cells in the lungs. This oxygen-rich blood then enters the left atrium, the right ventricle and is pumped by the left ventricle into the body.
In a transposition of the main arteries, the two main arteries are switched. The aorta connects to the right ventricle, instead of the left ventricle. The pulmonary trunk connects to the left ventricle, instead of to the right ventricle. Because of this, the pulmonary and the systemic circulation, which are normally connected, are separated. The oxygen-rich blood in the pulmonary circulation flows through the lungs, then via the left atrium and ventricle back into the pulmonary artery and back into the lungs. Deoxygenated blood flows through the body into the caval veins to the right atrium and ventricle into the aorta, back into the aorta.
The arterial switch surgery is the most common surgery these days to correct a transposition of the great arteries (TGA). You can view a TGA before surgery here: https://skfb.ly/6xrnt
What happens during the surgery?
- The arteries are cut just above the heart valves
- The coronary arteries are cut from the aorta and attached to the artery that goes to the lungs. The holes in the aorta are closed.
- The aorta is moved to the base of the pulmonary trunk. This will form the new aorta.
- The pulmonary trunk is moved and attached to the base of the aorta. These two together will form the new pulmonary artery.
This will result in a bloodflow that is similar to the flow from a normal heart.
This model shows a cut through a heart with transposition of the great arteries as it would show in a long axis echo plane. In case of a transposition of the main arteries, the places of the two main arteries are switched. The aorta connects to the right ventricle, instead of the left ventricle. The pulmonary trunk connects to the left ventricle, instead of the right ventricle. Because of this, the pulmonary and the systemic circulation, which are normally connected, are separated. The oxygen-rich blood in the pulmonary circulation flows through the lungs, then via the left atrium and ventricle back into the pulmonary artery and back into the lungs. Deoxygenated blood flows through the body into the caval veins to the right atrium and ventricle into the aorta, back into the aorta.
This model shows a cut through a heart with transposition of the great arteries as it would show in a short axis echo plane. In case of a transposition of the main arteries, the places of the two main arteries are switched. The aorta connects to the right ventricle, instead of the left ventricle. The pulmonary trunc connects to the left ventricle, instead of the right ventricle. Because of this, the pulmonary and the systemic circulation, which are normally connected, are separated. The Oxygen-rich blood in the pulmonary circulation flows through the lungs, then via the left atrium and ventricle back into the pulmonary artery and back into the lungs. Deoxygenated blood flows through the body into the caval veins to the right atrium and ventricle into the aorta, back into the aorta.
This model depicts the morphology of a common arterial trunk (CAT), a rare congenital disease. In this condition, the embryological structure known as the truncus arteriosus fails to properly divide into the pulmonary trunk and aorta.
ACYANOTIC CONGENITAL HEART DISEASES - LEFT-TO-RIGHT-SHUNTS
A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. The extent of the opening may vary from pin size to complete absence of the ventricular septum, creating one common ventricle.
Perimembranous VSD’s are located in the membranous septum, a relatively small portion of the septum located near the heart valves.
Muscular VSD’s are located in hte muscular portion of the ventricular septum. Many of these muscular VSD’s close spontaneously and do not require surgery.
The model depicts both a muscular and a perimembranous VSD.
ASD is a defect in the septum between the heart’s two upper chambers (atria).
This model shows an atrioventricular septal defect. A window was made in the right atrium to enable a view into the hart.
This model shows a 4 chamber plane cut through a heart with an atrioventricular septal defect to show the anatomy as seen on the ultrasound image.
Partial anomalous pulmonary venous connection (PAPVC) is a rare congenital cardiac defect. In PAPVC, the blood flow from a few of the pulmonary veins return to the right atrium instead of the left atrium. Usually, a single pulmonary vein is anomalous. This model shows a PAPV, where the anomalous right superior pulmonary pulmonary vein drains via the Superior Vena Cava into the right atrium instead of the left atrium.
ACYANOTIC CONGENITAL HEART DISEASES - OUTFLOW OBSTRUCTION
Coarctation of the aorta, also called aortic narrowing, is a congenital condition whereby the aorta is narrow. When a patient has a coarctation, the left ventricle has to work harder. Because the aorta is narrower, the left ventricle must generate a much higher pressure than normal in order to force enough blood through the aorta to deliver blood to the lower part of the body. If the narrowing is severe, the left ventricle might not be powerful enough to push blood through the coarctation, which results in a lack of blood to the lower half of the body. To see a model of a corrected coarctation of the aorta (with stent!) follow this link: https://skfb.ly/6KMsZ
Coarctation of the aorta, also called aortic narrowing, is a congenital condition whereby the aorta is narrow. When a patient has a coarctation, the left ventricle has to work harder. Because the aorta is narrower, the left ventricle must generate a much higher pressure than normal in order to force enough blood through the aorta to deliver blood to the lower part of the body. If the narrowing is severe, the left ventricle might not be powerful enough to push blood through the coarctation, which results in a lack of blood to the lower half of the body. A model depicting an uncorrected coarctation of the aorta can be found here: https://skfb.ly/6KMwH