What is Hypertrophic Cardiomyopathy?
Hypertrophic cardiomyopathy (HCM) is a heart disease characterized by thickening of the heart muscle (myocardium). It is a genetic or inherited disease. That is, it is inherited through parental genes. A child has a 50% chance of inheriting the disease if one of his or her parents has the gene.
HCM attacked one in 500 people. However, this is not always a cause for concern. Many people who have this gene, but do not show any symptoms, can even live normal and active lives. However, about 10% of those suffering from severe illness and are at high risk of serious diabetes. These include life-threatening conditions, namely arrhythmia (abnormal heartbeat) and sudden cardiac death.
HCM can inhibit the heart in pumping blood properly. Because of this, the amount of blood circulating in the body will be reduced. When this happens, vital organs, such as the brain and lungs, do not get enough oxygen and nutrients to function as normal.
HCM can be obstructive and non-obstructive. In some people, the disease makes the septum (the wall that separates the heart ventricles) swell. This makes it difficult for the heart to push blood into the lungs (obstructive). In other cases, the disease attacks the right ventricle so that it can only hold a small amount of blood. Therefore, even when there is no obstruction, the amount of blood that reaches vital organs will still be reduced.
Hypertrophic Cardiomyopathy Symptoms
Some cases of hypertrophic cardiomyopathy often go undetected and patients show few or no symptoms. This mild case also allows sufferers to live a normal life without any significant problems.
However, in some other cases, hypertrophic cardiomyopathy can cause some dangerous symptoms, for example:
- Shortness of breath
- Chest pain
- Irregular heart rhythm or arrhythmia
- Sudden death.
Hypertrophic Cardiomyopathy Types
There are two types of hypertrophic cardiomyopathy, namely obstructive hypertrophic cardiomyopathy and non-obstructive hypertrophic cardiomyopathy.
Obstructive hypertrophic cardiomyopathy
Obstructive hypertrophic cardiomyopathy is the most common type. In this case, the septum or muscle wall separating the two chambers of the heart becomes thicker than usual. As a result, thickened muscle walls will inhibit blood flow out of the heart.
Non-obstructive hypertrophic cardiomyopathy
In the case of non-obstructive hypertrophic cardiomyopathy, blockage of blood flow does not occur significantly. However, the left chamber of the heart remains stiff and makes it difficult for the heart to relax. This condition also reduces the flow of blood that the chambers store to be sent to other parts of the body.
Hypertrophic Cardiomyopathy Causes
Genetics
Hypertrophic cardiomyopathy is usually an inherited condition. Damaged genes can cause the heart muscle to thicken. You have a 50 percent chance of inheriting one of these genes if one of your parents develops hypertrophic cardiomyopathy.
Inheriting a gene doesn’t necessarily mean that you’ll have a symptomatic disease. Hypertrophic cardiomyopathy follows a dominant pattern of inheritance. However, symptoms don’t always develop in people with defective genes.
Other causes
Other possible causes of hypertrophic cardiomyopathy include aging and high blood pressure. In some cases, the cause of this condition is never identified.
Hypertrophic Cardiomyopathy Diagnosis
Various tests can be used to diagnose this condition, including:
Physical Examination
Your doctor will listen for a heart murmur or an unusual heartbeat. Heart murmurs can occur if the thickened heart muscle interferes with blood flow to the heart.
Echocardiogram
This is the most common diagnostic test for hypertrophic cardiomyopathy. An echocardiogram creates an image of the heart using sound waves. Your doctor may look for unusual movements.
Electrocardiogram
An electrocardiogram is used to measure electrical activity in the heart. Hypertrophic cardiomyopathy can cause abnormal results.
Holter Monitor
A Holter monitor is a portable electrocardiogram that you can wear all day. Your doctor will recommend that you wear it for 24 to 48 hours. This test aims to see how your heart rate changes during various activities.
MRI of the Heart
MRI of the heart uses a magnetic field to produce detailed images of the heart.
Cardiac Catheterization
This cardiac catheterization test is used to measure blood flow pressure in the heart and look for blockages. To do this test, your doctor will place a catheter in one of the arteries in your arm or near your groin.
The catheter is carefully connected through an artery to your heart. Once it reaches your heart, a dye is injected so your doctor can take detailed X-ray images.
Source:
- Image: Blausen Medical Communications, CC BY 3.0 https://creativecommons.org/licenses/by/3.0, via Wikimedia Commons
- Video: British Heart Foundation
