What Is Hypertrophic Cardiomyopathy?

Editor's Choice
Main Category: Heart Disease
Also Included In: Cardiovascular / Cardiology;  Genetics
Article Date: 08 Jun 2011 - 0:00 PST


Hypertrophic cardiomyopathy is a type of heart disease in which the heart muscle (myocardium) becomes thickened without any obvious cause. This prevents it from pumping effectively and can cause sudden cardiac death if left untreated. As the heart muscle thickens, the muscle cells can also disorganize which can complicate the delivery of electrical signals through the muscle. The heart muscle also becomes rigid which prevents the muscle from fully relaxing.

The disease appears to occur equally in men and women and can affect people of many ages including infants. It normally develops during childhood or young adulthood. Younger people with hypertrophic cardiomyopathy are likely to suffer a more severe form of the condition.

According to Medilexicon's medical dictionary hypertrophic cardiomyopathy is:

"thickening of the ventricular septum and walls of the left ventricle with marked myofibril disarray; often associated with greater thickening of the septum than of the free wall resulting in narrowing of the left ventricular outflow tract and dynamic outflow gradient; diastolic compliance is greatly impaired."

What are the signs and symptoms of hypertrophic cardiomyopathy?

A symptom is something the patient feels or reports, while a sign is something that other people, including the doctor detects. A headache may be an example of a symptom, while a rash may be an example of a sign.

A person can suffer hypertrophic cardiomyopathy and never feel any symptoms, but symptoms can appear at different stages of a person's life, ranging from teenage years to middle ages or older. A list of the possible symptoms are below:

• Chest pain when under stress (angina)
• Heartbeat is erratic (palpatations)
• Shortness of breath (dyspnea)
• Feeling faint or light headed (syncope)

What causes hypertrophic cardiomyopathy?

The exact cause of hypertrophic cardiomyopathy has not been fully identified, however it would appear that the condition is a result of genetic mutation. Studies have revealed that approximately half of people with hypertrophic cardiomyopathy have a close relative with the disease. This type of inheritance is called autosomal dominant.

The genetic cause of hypertrophic cardiomyopathy for people with no family history of the condition is known as de novo mutation. There might also be non-genetic influences that cause the disease. However, this is yet to be confirmed in research.

How is hypertrophic cardiomyopathy diagnosed?

When diagnosing hypertrophic cardiomyopathy, there are a variety of methods a doctor can choose from. These include:

• Carrying out a physical assessment - The patient will be asked about their medical history and what symptoms they are suffering/have suffered. Their heart will then be inspected for signs of valve leakage or obstruction.
• Using imaging tests - By producing an image of the heart, these tests help the doctor identify its condition. Methods include MRI (Magnetic Resonance Imaging) scans, Chest X-rays and echocardiograms. Echocardiograms use sound waves and are very useful in diagnosis of hypertrophic cardiomyopathy, as they identify heart muscle thickness, chamber size, range of valve movement, flow of blood and extent of obstruction.
• Taking a blood sample - There are specific gene mutations that can be identified by testing a sample of someone's blood. The gene mutations that are known to cause hypertrophic cardiomyopathy can be identified this way.
• Monitoring how the body responds to exercise - An effective way of checking the heart's condition is by observing it during or just after exercise. This can be done a number of different ways such as an oxygen consumption test where the patient breathes into a mask during exercise. Other methods include: a thallium scan, monitoring the change in blood pressure or performing an echocardiogram after exercise.
• Performing cardiac catheterization - This involves insertion of a catheter into the left ventricle and ascending aorta so that the pressure difference between them can be gauged. If a person is suffering from hypertrophic cardiomyopathy the pressures will differ.

What are the treatment options for hypertrophic cardiomyopathy?

It is important, when choosing the appropriate treatment method, to consider factors such as the risk of the procedure and severity of the condition. The following are types of treatment available to people with hypertrophic cardiomyopathy:

• Surgical myectomy - This is an open heart operation, in which a section of the overgrown muscle is removed and any obstructions cleared. Due to its complexity, an experienced surgeon would need to perform this procedure. Surgical myectomy is proven to be very successful at treating hypertrophic cardiomyopathy and has a low mortality rate of 1/100.
• Defibrillator therapy - A defibrillator may be required to prevent cardiac death for someone very high risk. It monitors the rhythm of the heart and corrects any irregularities using tiny electric shocks.
• Cardiac transplantation - This procedure also known as a heart transplant, involves replacing the diseased heart with a healthy heart from a recently deceased donor. It is a last resort reserved for when all other treatment methods have proved unsuccessful.
• Alcohol septal ablation - A less invasive alternative to surgery, alcohol septal ablation involves injection of alcohol into the artery that leads to the affected section of the heart. This leads to a small controlled heart attack (localized myocardial infarction) which can help alleviate the symptoms and lessen the extent of the obstruction.
• Medication - Use of certain medication can partially remove the obstruction and relax the heart muscles. Types of medication that can be used include anti-arrhythmia drugs and beta-blockers.
• Ventricular pacing - Using a pacemaker can prove useful in aiding the contraction of the left ventricle but is not consistently successful in all cases of hypertrophic cardiomyopathy.

Written by Mike Paddock
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

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