Powered By
Continue with Facebook
Continue with your email
Cardiomyopathy is a condition that affects your heart muscle and can make it harder for your heart to pump blood the way it should. Two common types are hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM). They can cause some of the same symptoms, but they affect the heart in different ways.
A key difference is what happens to the heart’s main pumping chamber, the left ventricle. With HCM, the heart muscle — especially the left ventricle — becomes thicker than normal. That extra thickness can make it harder for the heart to relax and fill properly between beats. In some cases, it can affect blood flow out of the heart. Furthermore, a thicker heart muscle does not necessarily imply a stronger heart muscle. In some people with HCM, the heart muscle may be weaker because the muscle fibers are not properly aligned.
With DCM, the heart muscle is often not thicker, but the left ventricle (and sometimes the right ventricle) becomes enlarged and stretched out. When that happens, the heart may not squeeze as strongly as it should.
Knowing the differences between HCM and DCM can help you understand symptoms, test results, and treatment options. It can also make it easier to talk with your healthcare provider about what’s going on and what to do next.
HCM is considered a genetic disorder that’s often inherited. If you have a parent, child, or sibling with the condition, your likelihood of also developing the condition is 50 percent. If a family member has been diagnosed with HCM, talk with your doctor about whether you should be checked.
Only about 1 in 5 people with HCM know they have the condition because it doesn’t always cause symptoms. Still, HCM can be serious. In rare cases, it can lead to sudden cardiac arrest, even in people who seem healthy. In the United States, HCM is the leading cause of cardiac death in people younger than 35, including some athletes.
According to StatPearls, an online medical reference written and reviewed by healthcare professionals, about 750,000 people in the U.S. have HCM, and it’s more common in men than in women. StatPearls reports that HCM is often diagnosed in people in their 20s or 30s but can be found at any age. Females who are diagnosed later in life typically have a worse prognosis (outlook) than males.
DCM is a type of heart disease that makes the heart muscle stretch and become larger. It usually affects the left ventricle, but it can affect both sides of the heart. DCM is often diagnosed when the left ventricle isn’t pumping well. For example, it may pump out only about 40 percent of the blood with each beat, compared with about 60 percent in a typical heart.
Researchers estimate that about 6 out of every 100,000 people are diagnosed with DCM each year. According to the Merck Manual, a widely used medical reference, men are three times more likely to have the condition than women, and those with African ancestry are twice as likely as white people to have DCM. Most people find out that they have the condition between the ages of 20 and 60, but it can be present at any age, including in children.
While DCM can be genetically inherited, in some cases, it’s caused by another condition. Common causes include coronary artery disease, infections, high blood pressure, alcohol or drug use, arrhythmia (abnormal heart rhythm), certain medications (including some cancer treatments), and pregnancy. When the cause of DCM is not clear, the condition is called idiopathic DCM. If you have DCM, getting treatment early can help lower your risk of heart failure.
Although both DCM and HCM are types of cardiomyopathy, they change your heart’s shape and how well it works in different ways. DCM causes a heart chamber to stretch and become enlarged, and the walls may become thinner. HCM causes the heart muscle to become thicker than normal, especially in the left ventricle.
These differences also affect how your heart works. With DCM, the heart usually can’t pump blood as strongly. In HCM, the thickened muscle can block or narrow blood flow out of the heart. Here are some other key differences in symptoms, diagnosis, and treatment.
In general, cardiomyopathy can cause chest pain, shortness of breath, dizziness, excessive tiredness, and swelling, particularly in your ankles and lower legs. But the type of cardiomyopathy you have — HCM or DCM — will influence your specific symptoms.
Most people with HCM have very few symptoms or none at all. However, some people may have chest pain, irregular heartbeats, fainting, or shortness of breath. In rare cases, HCM can lead to sudden cardiac arrest, which is one reason it’s important to get checked if you have symptoms or a family history.
Meanwhile, DCM symptoms often happen because the heart can’t pump blood as well as it should. These symptoms can include shortness of breath, chest pain, rapid pulse, irregular heartbeats, leg swelling, and waking from sleep feeling out of breath. Serious complications can happen in advanced cases, so it’s important to talk with your doctor if you notice these symptoms.
When diagnosing cardiomyopathy, your healthcare provider will often use the same tests regardless of whether you have HCM or DCM. As the results come in, they may order more specific testing to help identify which type of cardiomyopathy you have.
In general, your provider may begin with imaging tests, stress tests, and blood work. These tests give them an overview of your heart’s condition and how it is working, as well as its size and shape.
Some of the tests they may order include:
The most reliable ways to diagnose HCM are through the use of an echocardiogram and a cardiac MRI. Evaluating family history and conducting genetic testing are also important components to reach a reliable diagnosis.
Meanwhile, to diagnose DCM, healthcare providers typically start with a physical exam, a chest X-ray, an echocardiogram, and a blood test. From there, they may order more tests, like the use of a Holter monitor and stress test, to figure out how well your heart is working before moving on to more extensive testing.
If you have HCM, there are very few medications designed specifically for the condition. Your healthcare provider will likely prescribe medications to treat your symptoms, such as anti-arrhythmic medications, beta-blockers, and calcium channel blockers.
Some newer medicines treat the heart muscle itself. These drugs are called cardiac myosin inhibitors. They can help the thick heart muscle relax and let blood flow more easily.
The U.S. Food and Drug Administration (FDA) has approved two myosin inhibitor medicines for people with obstructive HCM: mavacamten (Camzyos) and aficamten (Myqorzo). Your doctor will decide if one of these is right for you based on your symptoms and test results.
Several procedures may help, including a septal ablation. In this minimally invasive procedure, a doctor injects a small amount of concentrated alcohol into an artery that supplies the thickened heart muscle. The alcohol purposely damages a small area of the thickened muscle. As it heals, that spot turns into scar tissue, which reduces the thickness and helps blood flow more easily. Another option is open-heart surgery called septal myectomy, where a surgeon removes part of the thickened heart muscle to improve blood flow.
Some people need an implantable cardioverter-defibrillator (ICD), which shocks the heart when a life-threatening arrhythmia occurs and causes it to return to a normal rhythm. Most severe HCM cases require heart transplantation.
If you have DCM, treatment aims to relieve symptoms, help you live longer, and protect your heart. Most people need a few daily medicines that work together.
Several treatments can improve how your heart works. These include inserting a pacemaker to help regulate your heart rhythm and make heart contractions more efficient, or adding an ICD to prevent sudden cardiac death due to arrhythmia.
Exercise and cardiac rehabilitation programs can also be helpful. In fact, researchers have found that cardiac rehab not only improves symptoms and reduces the likelihood of cardiac events but may also improve chances of survival with DCM. Ask your doctor for a referral to a cardiac rehabilitation program if it’s available to you.
In more severe cases, or if other treatment methods have failed, a left ventricular assist device may be recommended. These devices help your heart pump better. Heart valve surgery and heart transplants are other options considered in severe cases. These are used when medicines and devices are not enough.
HCM and DCM are different conditions, but both affect how the heart works and can change over time. Understanding which type of cardiomyopathy you have can help you know what symptoms to watch for and what treatments may help. If you have concerns about your symptoms or diagnosis, talk with your healthcare provider about the next steps.
On MyHeartDiseaseTeam, people share their experiences with heart disease, get advice, and find support from others who understand.
If you’ve been diagnosed with cardiomyopathy, what step have you taken that has helped your heart health the most? Let others know in the comments below.
Get updates directly to your inbox.
Continue with Facebook
Continue with your email
Become a member to get even more
Join
We'd love to hear from you! Please share your name and email to post and read comments.
You'll also get the latest articles directly to your inbox.