HYPERTROPHIC CARDIOMYOPATHY

Introduction;

 Cardiac Enlargement;

Cardiac enlargement refers to an increase in the size of the heart. There are two types of cardiac enlargement: hypertrophy and dilation. (Though usually occurring separately, they may occur at the same time.) Hypertrophy involves an increase in the thickness of the heart muscle. Dilation involves an increase in the size of the inside cavity of a chamber of the heart. Hypertrophy usually occurs in only one chamber while dilation may occur in one, two, three, or all of the chambers, based on its cause. In most cases, cardiac enlargement is abnormal and accompanied by additional cardiovascular problems. The one exception is regular aerobic exercise, which produces a beneficial enlargement involving both hypertrophy and dilation of the heart.

 Cardiac Hypertrophy:

Hypertrophy, or thickening, of the heart muscle occurs in response to increased stress on the heart. It typically involves one of the bottom chambers of the heart, which are known as the ventricles. The right ventricle pumps blood to the lungs and the left ventricle pumps blood to the body. The most common causes of hypertrophy are related to increased blood pressure in either the lungs or the body. The extra work of pumping blood against the increased pressure causes the ventricle to thicken over time, the same way a body muscle increases in mass in response to weightlifting.
High blood pressure, or hypertension, is the most frequent cause of left ventricular hypertrophy (LVH). Stenosis of the aortic valve – a condition in which, for a variety of reasons, this heart valve cannot open fully – is another common cause of LVH. Hypertrophic cardiomyopathy (a disease previously known as idiopathic hypertrophic subaortic stenosis or IHSS), and the ongoing use of cocaine round out the list of most common causes of LVH. Hypertrophic cardiomyopathy is a genetic disease related to weakness of the individual muscle fibers of the heart. These fibers need to work harder to pump blood and become thickened over time. Hypertrophic cardiomyopathy occurs in 1 in 500 people and is the most common cardiac cause of sudden death in young athletes.

The most common causes of right ventricle hypertrophy (RVH) are diseases that damage the lung like emphysema and cystic fibrosis. These diseases destroy blood vessels in the lung, causing increased pressure in the remaining vessels. Conditions that decrease oxygen levels, such as chronic bronchitis and sleep apnea, also lead to RVH. Stenosis of the pulmonic heart valve, repeated blood clots to the lungs (chronic pulmonary embolism), and primary pulmonary hypertension are a few of the remaining causes of RVH.

Causes of HCM-Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy is often asymmetrical, meaning one part of the heart is thicker than the other parts. The condition is usually passed down through families (inherited). It is believed to be a result of several problems (defects) with the genes that control heart muscle growth.

Younger people are likely to have a more severe form of hypertrophic cardiomyopathy. However, the condition is seen in people of all ages.

Symptoms of HCM(Hypertrophic Cardiomyopathy)

• Chest pain
• Dizziness
• Fainting, especially during exercise
• Heart failure (in some patients)
• High blood pressure (hypertension)
• Light-headedness, especially with or after activity or exercise
• Sensation of feeling the heart beat (palpitations)
• Shortness of breath

Other symptoms that may occur are:

• Fatigue, reduced activity tolerance
• Shortness of breath when lying down

Some patients have no symptoms. They may not even realize they have the condition until it is found during a routine medical exam.
The first symptom of hypertrophic cardiomyopathy among many young patients is sudden collapse and possible death. This is caused by very abnormal heart rhythms(arrhythmias), or from the blockage of blood leaving the heart to the rest of the body.
Hypertrophic cardiomyopathy is a major cause of death in young athletes who seem completely healthy but die during heavy exercise. However, certain normal changes in athletes' hearts can confuse the diagnosis

Exams and Tests;

The doctor will perform a physical exam and listen to the heart and lungs with a stethoscope. Listening with a stethoscope may reveal abnormal heart sounds or a murmur. These sounds may change with different body positions.
The pulse in your arms and neck will also be checked. The doctor may feel an abnormal heartbeat in the chest.
Tests used to diagnose heart muscle thickness, problems with blood flow, or leaky heart valves (mitral valve regurgitation) may include:

• Chest x-ray
• ECG
• Echocardiography (the most common test) with Doppler ultrasound
• 24-hour Holter monitor (heart monitor)
• Cardiac catheterization
• MRI of the heart
• Transesophageal echocardiogram (TEE)

Not all of these tests are useful for evaluating all of these conditions.
Blood tests may be done to rule out other possible diseases.
If you are diagnosed with hypertrophic cardiomyopathy, your doctor may recommend that your close blood relatives (family members) be screened for the condition

Treatment of HCM;

• In all patients with hypertrophic cardiomyopathy risk stratification is essential to attempt to ascertain which patients are at risk for sudden cardiac death. In those patients deemed to be at high risk the benefits and infrequent complications of defibrillator therapy are discussed; devices have been implanted in as many as 15% of patients.
• Treatment of symptoms of obstructive HCM is directed towards decreasing the left ventricular outflow tract gradient and symptoms of dyspnea, chest pain and syncope.
•  Medical therapy is successful in the majority of patients. The first medication that is routinely used is a beta-blocker (atenolol,propranolol). If symptoms and gradient persist, disopyramide may be added to the beta-blocker. Alternately a calcium channel blocker such as verapamil may be substituted for a beta blocker.
• It should be stressed that most patients' symptoms may be managed medically without needing to resort to interventions such as surgical septal myectomy, alcohol septal ablation or pacing. Severe symptoms in non-obstructive HCM may actually be more difficult to treat because there is no obvious target (obstruction) to treat.
• Medical therapy with verapamil and beta-blockade may improve symptoms. Diuretics should be avoided, as they reduce the intravascular volume of blood, decreasing the amount of blood available to distend the left ventricular outflow tract, leading to an increase in the obstruction to the outflow of blood in the left ventricle.

Complications;

• Dilated cardiomyopathy
• Heart failure
• Life-threatening heart rhythm problems (arrhythmias)
• Severe injury from fainting

Prevention;

If you are diagnosed with hypertrophic cardiomyopathy, your doctor may recommend that your close blood relatives (family members) be screened for the condition.

Some patients with mild forms of hypertrophic cardiomyopathy are only diagnosed by screening echocardiograms because of their known family history.

If you have high blood pressure, make sure you take your medication and follow your doctor's recommendations

Please Note;

Call for an appointment with your doctor

if:

You have any symptoms of hypertrophic cardiomyopathy

You develop chest pain, palpitations, faintness, or other new or unexplained symptoms