Cardiomyopathy treatment

- [Voiceover] Let's look at the treatment of cardiomyopathy based on the physiology of the disease. To do so, I'm gonna just draw here a simplified diagram of the cardiac system. I want you to think of the cardiovascular system as the heart, as a series of two pumps that are separated by the lungs, up here, and the body. Kinda think of the body as two tanks. Over here, on the left side, we'll have blood filled in this tank. This blood enters into the right heart and the heart pumps this blood to the lungs. In the lungs, the blood is oxygenated. It returns to the left heart where it is then pumped back to the body. If you think about this second tank, the heart has to pump this blood enough to get into this normal range. These dotted lines, here, are gonna represent a normal range in order to get that blood adequately out to the body where it is used. Here, we'll kinda demonstrate this mixing of blood with a purple color, used by the body's organs, like the brain, and the intestines, and the muscles and everything. That blood now is de-oxygenated and returns back to the heart, here. That's how I want you to kinda think of a normal flow of blood in the cardiac system. In cardiomyopathy, you have a failure of this system. When it fails, the heart is not able to adequately pump blood out. This, here, is decreased. When you don't get an adequate outflow of blood, this tank isn't filled to a level that's able to adequately perfuse the body. Also, over here, if the blood isn't coming out of the heart, cuz you have a heart failure, it's gonna get backed up in this tank, and this tank is gonna be overflowing. If you think of cardiomyopathy in this way, you can see three areas in which the disease can be treated. In the center, here, the main cause of cardiomyopathy is that you have a pump failure. Over here on the left, you have this backup of blood flow. Over here on the right, you have a decreased outflow. If you think about it this way, you can see the three major targets of how cardiomyopathy can be treated. For each of these three mechanisms, I'm gonna talk about a few different treatment options and what types of cardiomyopathy they pertain to. I'm gonna just write in the types of cardiomyopathy, here. I'll use DCM to abbreviate for dilated cardiomyopathy, and RCM for restrictive cardiomyopathy, and HCM for hypertrophic cardiomyopathy. Let's start with treatments that address the backup of fluid caused by this heart failure. The first thing that someone with cardiomyopathy can do are lifestyle changes, such as a low-salt diet. Salt is made up of sodium and sodium is what determines the amount of fluid the body retains. If you have a low-salt diet, the body will try and get rid of this backed-up fluid. This is a primary treatment for both dilated cardiomyopathy and restrictive cardiomyopathy. If a low-salt diet is not sufficient, diuretics can be added to the treatment regimen. Diuretics have the same effect, although they are more efficient at decreasing this backed-up blood flow. So, that's also used in dilated cardiomyopathy and restrictive cardiomyopathy. The last medication I wanna mention, here, for treating the backup are ACE inhibitors. They are also used in dilated cardiomyopathy and restrictive cardiomyopathy. Notice that none of these treatments are used in hypertrophic cardiomyopathy, and that's because hypertrophic cardiomyopathy only results in symptoms intermittently. Individuals with hypertrophic cardiomyopathy don't typically have these signs and symptoms of fluid backup, so that mechanism does not need to be treated. Let's move on to the pump failure and treatments that directly address what's going on in the heart. The first one to mention are two types of medications that have similar effects. Those are beta blockers and calcium channel blockers, which I'll abbreviate CCB. These medications are used in both dilated cardiomyopathy and hypertrophic cardiomyopathy, but they're used for different reasons. In dilated cardiomyopathy, beta blockers and calcium channel blockers decrease the oxygen demand of the heart, which can decrease some of the symptoms when the heart is overworked. However, in hypertrophic cardiomyopathy, these medications treat the disease by a different means. These medications also slow down the heart rate. In hypertrophic cardiomyopathy, this is important because they decrease heart rate, increases the time in which the heart is spent in diastole, or the filling phase. Then, when it contracts, there's an increased outflow. The next medication, here, is Digoxin. Digoxin isn't used all that frequently, but it can be used for dilated cardiomyopathy. What it does is it increases the contractile strength of the heart muscle to overcome this pump failure. It's really only used in dilated cardiomyopathy. These are the medications that are used to treat the pump failure, but there's also a few devices or procedures that can be done to treat the pump failure in cardiomyopathy. The first one I wanna mention is a pacemaker. A pacemaker is a device that is actually implanted into the heart to make sure that the heart beats regularly. In dilated cardiomyopathy and restrictive cardiomyopathy, the disease can become so severe that the conduction pathways that cause the heart to beat regularly can become dysfunctional. A pacemaker can be used to improve the heart's ability to beat on a regular basis. That's used to treat dilated cardiomyopathy and restrictive cardiomyopathy. The next treatment of the pump failure is something known as septal reduction. Septal reduction is only used for hypertrophic cardiomyopathy because hypertrophic cardiomyopathy is caused by this asymmetric enlargement of the ventricular septum. If you reduce the size of the septum, you decrease the severity of disease. A septal reduction can actually be done in two different ways. It can be done by actually injecting alcohol into the septum, which causes the muscle cells to reduce in size. Or, it can be done surgically through a procedure known as a septal myomectomy. The last treatment for pump failure is a transplant. A heart transplant is really a last-ditch effort to treat any of the forms of cardiomyopathy. Now, let's move on to this last target of treatment, which is the decreased outflow. There's really only one medication that's used on a regular basis to specifically treat this mechanism. That, we actually already mentioned over in the backup, is ACE inhibitors. What ACE inhibitors do is they cause dilation of the arterials, here, which decreases the resistance in the arterial system, of which the heart has to pump against. For the same contraction strength, you can get an increased outflow from the heart. This is used to treat, once again, dilated cardiomyopathy and restrictive cardiomyopathy. This is just a brief overview of the treatments of the different types of cardiomyopathy. If you can remember this simplified diagram of the cardiovascular system and how cardiomyopathy causes a pump failure with subsequent backup of fluids, as well as a decreased outflow, you can remember that there are three main targets of the treatments for cardiomyopathy. They vary somewhat depending on the specific type of cardiomyopathy, whether it be dilated cardiomyopathy, restrictive cardiomyopathy or hypertrophic cardiomyopathy.