Hypertrophic Cardiomyopathy: Causes, and Symptoms

Hypertrophic cardiomyopathy (HCM) is a genetic heart disease characterized by abnormal thickening of your heart’s muscle walls (especially the left ventricle). This thickening can reduce the internal volume of your heart’s chamber and negatively affect its blood pumping ability. HCM is usually a familial hereditary condition and is often diagnosed in young or middle age. The disease can progress without symptoms, but in some patients it can cause complaints such as shortness of breath, chest pain, and palpitations.

What is Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy (HCM) is abnormal thickening of your heart’s muscle tissue (myocardium). This thickening usually affects your heart’s left lower chamber (left ventricle) and is most commonly seen in the area close to the beginning of the main vessel (aorta) from which blood exits the heart. The thickened muscle can make it difficult for your heart to relax and fill, or it can prevent blood from being pumped out of the heart.

What are the Types of Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy is divided into two main types according to the location of the thickened heart muscle and whether it obstructs blood flow from the heart. Obstructive HCM can cause more pronounced symptoms because it blocks blood flow from the heart, while non-obstructive HCM does not obstruct blood flow. This distinction plays an important role in monitoring the disease and determining the treatment plan.

The main types of HCM are:

Obstructive Hypertrophic Cardiomyopathy:

The thickened heart muscle physically blocks blood flow from your heart’s left lower chamber. This obstruction causes your heart to work harder and your symptoms to become more pronounced. Especially during exercise, this obstruction can worsen as your heart beats faster.

Non-obstructive Hypertrophic Cardiomyopathy:

The heart muscle is thickened but does not obstruct blood flow. It can affect your heart’s ability to relax and fill. This type usually has fewer symptoms, but it can still carry risks such as heart failure or rhythm disorders.

What Causes Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy is a genetic disease and usually passes from generation to generation through autosomal dominant inheritance. The genetic mutations that cause the disease affect the protein structure of heart muscle cells, leading to abnormal muscle growth. If a parent has HCM, the likelihood of their child developing the disease is 50%. Therefore, it is of great importance for people with a family history of HCM to have regular cardiological evaluations.

What are the Symptoms of Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy may not cause any symptoms for years in some patients. However, as the disease progresses or heart muscle thickening increases, symptoms may appear. The most common symptoms are shortness of breath, chest pain especially during exertion, and palpitations. Fainting or dizziness are also important symptoms of HCM and may be harbingers of a more serious condition.

Let’s examine the most common symptoms of HCM in detail:

• Shortness of Breath: Due to your heart’s inability to pump blood adequately, you feel shortness of breath, especially during physical activity.
• Chest Pain (Angina): The increased oxygen need of the heart muscle can cause chest pain, especially with exertion.
• Palpitations: Disorders in heart rhythm (arrhythmia) create the feeling that your heart is beating irregularly or rapidly.
• Fainting or Dizziness: Due to restricted blood flow or serious rhythm disorders, blood flow to the brain may decrease and fainting (syncope) may occur.
• Fatigue: Inefficient functioning of the heart can lead to general fatigue and energy decline.

How is Hypertrophic Cardiomyopathy Diagnosed?

Hypertrophic cardiomyopathy diagnosis is usually made through screening tests performed when your symptoms are suspected or when there is a family history of the disease. The most important diagnostic tool is echocardiography, which is an ultrasound of your heart. This test shows the thickness of your heart muscle and your heart’s pumping function in detail. Additionally, ECG, Holter monitoring, and genetic tests are also used in the diagnostic process.

The main methods used in HCM diagnosis are:

• Physical Examination: Your doctor may hear a murmur while listening to your heart sounds.
• Echocardiography (Heart Ultrasound): This is the test that most clearly shows heart muscle thickness, chamber sizes, and heart pumping power.
• Electrocardiography (ECG): By measuring your heart’s electrical activity, it can show rhythm disorders or signs of heart muscle thickening.
• Holter Monitoring: Records your heart’s rhythm for 24 or 48 hours to detect irregular beats (arrhythmia).
• Cardiac MR: Used to examine heart muscle in more detail when clear images cannot be obtained with echocardiography.
• Genetic Tests: Genetic counseling and tests may be recommended to determine the genetic cause of the disease and screen family members.

How is Hypertrophic Cardiomyopathy Treated?

Although there is no permanent cure for hypertrophic cardiomyopathy, there are various treatment methods to manage your symptoms and reduce the risk of sudden death. Treatment is planned individually according to the type of disease and the severity of your symptoms. Medications, interventional procedures for obstructive conditions, or ICD implantation in patients with high risk of sudden death are the most commonly used treatment options.

The methods applied in HCM treatment are:

Medication Treatment:

• Beta Blockers: Reduce symptoms by making your heart beat slower and stronger.
• Calcium Channel Blockers: Facilitate relaxation of heart muscle, increasing the heart’s filling capacity.

Interventional Treatments:

• Septal Ablation: A procedure to reduce thickened muscle tissue with alcohol injection.
• Surgical Myectomy: Surgical removal of thickened muscle tissue.

Implantable Cardioverter Defibrillator (ICD)

For patients with high risk of sudden death, a device is implanted that detects irregular heart rhythm and delivers a shock to restore normal rhythm.

Lifestyle Changes

It is important to avoid heavy physical exercises and adopt a healthy lifestyle.

What are the Risks and Complications of Hypertrophic Cardiomyopathy?

Hypertrophic cardiomyopathy can carry serious risks and complications if left untreated. The most important and most feared complication of this disease is sudden cardiac arrest. The irregular structure in the heart muscle can cause life-threatening rhythm disorders such as ventricular fibrillation. This condition can lead to sudden death as a result of the heart’s inability to pump blood effectively. Other serious risks include worsening heart failure, stroke, and arrhythmias such as atrial fibrillation. The severity of these complications depends on the type of disease and the individual’s general health condition.

The main complications that HCM can cause are:

• Sudden Cardiac Arrest and Ventricular Fibrillation (VF): HCM is one of the most common causes of sudden cardiac death, especially in young people. The thickened and irregularly structured heart muscle can cause the heart’s lower chambers (ventricles) to quiver chaotically (ventricular fibrillation). This completely stops the heart’s ability to pump blood and is fatal if emergency intervention is not provided.
• Heart Failure: Thickening of heart muscle can reduce the heart’s pumping efficiency, leading to heart failure.
• Atrial Fibrillation (AFib): Irregular heart rhythm (AFib) can cause clot formation in your heart, and this clot can go to the brain and cause stroke.
• Mitral Valve Problems: Thickened muscle tissue can disrupt mitral valve function and cause valve leakage.

Is it Possible to Prevent Hypertrophic Cardiomyopathy?

Since hypertrophic cardiomyopathy is a genetic disease, it is not possible to prevent the formation of the disease. However, with early diagnosis and regular follow-up of the disease, you can minimize complications and risks. It is of great importance for individuals with a family history of HCM to have regular cardiological check-ups even if they have no symptoms. Early diagnosis enables the most effective planning of treatment.

Preventive measures that can be taken for HCM are limited due to the genetic nature of the disease. However, for disease management and risk reduction, you can:

• Family Screening: If there is a history of HCM in your family, you and your relatives should be evaluated by a cardiologist.
• Regular Check-ups: After diagnosis, you should have regular doctor follow-up and check-ups.
• Lifestyle Changes: According to your doctor’s recommendation, you should avoid heavy physical activities and prefer regular, light exercises.

When Should You See a Doctor?

If there is a history of hypertrophic cardiomyopathy in your family or if you experience symptoms such as shortness of breath, chest pain, palpitations, fainting, you should consult a cardiology specialist without delay. Especially symptoms that appear during exertion may be a sign of your heart health and detailed evaluation should be performed.

You need to see a doctor immediately in the following situations:

• Family History: If there is a history of hypertrophic cardiomyopathy or sudden cardiac death in your close relatives (mother, father, sibling).
• Exertion-Related Symptoms: If you feel shortness of breath, chest pain, or dizziness during or after exercise.
• Frequent Palpitations: If you frequently feel that your heart is beating irregularly or rapidly.
• Fainting (Syncope): If you experience unexplained fainting episodes.
• Heavy Activity Restriction: If you have symptoms that prevent you from doing heavy physical activity in your daily life.

Reference: Hypertrophic cardiomyopathy