Welcome to Lesson 2 of ACC's Transcatheter Valve Certification Overview Course. This learning activity was developed by myself. I am Liza St. Clair and I will also be narrating this presentation. The purpose of this lesson is to provide an understanding of valvular anatomy and pathophysiology so we can better understand the valvular heart disease process. Our objectives for this module is to provide an overview of the different types and causes of heart valve disease along with the common signs and symptoms patients will present with who are suffering from this disease. Valvular heart disease is when any valve in the heart has damage or is diseased. The normal heart has four chambers, the right and left atria, and the right and left ventricle, and four valves. The valves open and close to control or regulate the blood flowing into the heart and then away from the heart. Three of the valves are composed of three leaflets or flaps that work together to open and close to allow blood to flow across the opening. The mitral valve only has two leaflets as shown in the bottom right-hand corner. Healthy heart valves and leaflets are able to open fully and close the valve fully during the heartbeat, but diseased valves might not fully open or close. Any valve in the heart can become diseased, but the aortic valve is most commonly affected. In valve stenosis, the valve opening is narrowed. The narrowing requires increased pressure within the heart to pump blood across a smaller opening. Eventually, this reduces the heart's ability to pump blood to the body. The extra work of the heart can cause the heart muscle to thicken and enlarge, and eventually the strain can cause a weakened heart muscle and can ultimately lead to heart failure and other serious problems. In mitral valve prolapse, the valve leaflets do not close smoothly or evenly, but bulge upward into the left atrium. In some cases, the prolapse valve lets a small amount of blood leak backward through the valve, called regurgitation, which may cause a heart murmur. Degenerative or primary mitral regurgitation means that there is something intrinsically wrong with the mitral valve itself that causes it to leak. The leak is due to the prolapse leaflet or a ruptured cord that causes the leaflet to become partially detached and flail. The second category of mitral regurgitation is functional or secondary mitral regurgitation and is caused due to cardiomyopathy or an enlarged left ventricle. The enlarged left ventricle can lead to tethering of the mitral valve leaflets itself, in turn causing them not to meet in the center. In most cases, mitral regurgitation can be treated with open-heart surgical mitral valve intervention. However, a number of high-risk patients who are judged by the heart team to be too high-risk for surgery can appropriately be treated with the transcatheter mitral valve tear procedure. So, to summarize, our current transcatheter valve therapies aim to treat valve stenosis, which is a narrowing of the valve opening, and mitral valve regurgitation, which is when blood leaks back into the chamber that it came from and not enough blood can be pushed forward through the heart. Risk factors for developing heart valve disease include high cholesterol, hypertension, and diabetes. Other common causes of heart valve disease include congenital defects and other illnesses such as endocarditis or rheumatic fever. However, the most common is due to older age. As we age, there is a degenerative process of the heart valve. As noted earlier, the strain on the heart caused by the narrowed valve opening can cause a weakened heart muscle or decreased blood flow, which can ultimately lead to heart failure. Therefore, many patients will exhibit the same symptoms as heart failure, and this includes dizziness, fatigue, trouble breathing, chest pain, swollen legs, or a decreased appetite. Sadly, valvular heart disease is underdiagnosed. This illustration shows the number of estimated patients diagnosed with severe symptomatic aortic stenosis in the European Union by age and their proportion of patients remaining undiagnosed. Please also take note of how little many of those diagnosed patients are actually undergoing a surgical AVR or TAVR procedure. And this is often due to the fact that many of those that are diagnosed with valvular heart disease are diagnosed too late. As noted here, many patients do not exhibit symptoms of aortic valve stenosis until stage D of the disease process. The same is also true for mitral valve detrinitive or primary regurgitation. And lastly, for mitral valve functional or secondary regurgitation, the symptoms are usually exhibited earlier in stage A, and attempts are made to first manage the disease process most often with medications. And a surgical or transcatheter intervention is not indicated until stage D. This concludes Lesson 2 of 4. Thank you for your participation.

valvular heart disease

aortic valve

valve stenosis

mitral valve prolapse

mitral regurgitation