Hypertrophic cardiomyopathy
Hypertrophic Cardiomyopathy (HCM) is a genetic condition that causes the heart muscle to become abnormally thickened (hypertrophied), especially in the left ventricle. This thickening can make it harder for the heart to pump blood efficiently and can lead to various complications. Let me explain this condition in more detail.
What is Hypertrophic Cardiomyopathy (HCM)?
HCM is a disorder where the walls of the left ventricle become thicker than normal, often without any obvious cause. This abnormal thickening can affect the heart's ability to pump blood and may obstruct blood flow, particularly out of the left ventricle into the aorta.
Hypertrophic Cardiomyopathy (HCM) is a genetic condition that causes the heart muscle to become abnormally thickened (hypertrophied), especially in the left ventricle. This thickening can make it harder for the heart to pump blood efficiently and can lead to various complications. Let me explain this condition in more detail.
What is Hypertrophic Cardiomyopathy (HCM)?
HCM is a disorder where the walls of the left ventricle become thicker than normal, often without any obvious cause. This abnormal thickening can affect the heart's ability to pump blood and may obstruct blood flow, particularly out of the left ventricle into the aorta.
Key Features of HCM:
Thickening of the Heart Muscle:
The left ventricle's muscle becomes abnormally thickened, which can make the chamber smaller and reduce the space available for blood flow. This is often seen in the interventricular septum (the wall between the left and right ventricles).
Obstruction of Blood Flow:
In some cases, the thickened heart muscle can obstruct the flow of blood from the left ventricle into the aorta, a condition known as obstructive hypertrophic cardiomyopathy (oHCM).
This obstruction can increase the pressure in the left ventricle and cause symptoms like shortness of breath and chest pain.
Arrhythmias (Irregular Heart Rhythms):
The thickening of the heart muscle and the changes in heart structure can cause electrical disturbances, leading to arrhythmias. These can range from mild palpitations to life-threatening conditions like ventricular fibrillation.
Impaired Heart Function:
Over time, the thickened heart muscle can become stiff, impairing the heart’s ability to relax and fill properly during diastole (when the heart is at rest). This can lead to diastolic dysfunction and symptoms of heart failure.
Causes of HCM:
HCM is primarily genetic and is caused by mutations in the genes that control the proteins involved in the contraction of the heart muscle. The condition is typically inherited in an autosomal dominant pattern, meaning that one copy of the mutated gene is enough to cause the disorder.
In many cases, a person with HCM inherits the condition from one parent. However, some cases may result from spontaneous mutations that are not inherited.
Symptoms of HCM:
The severity of symptoms can vary widely. Some people may have no symptoms at all, while others may experience:
Shortness of breath (especially with exertion)
Chest pain (angina), often due to reduced blood flow to the heart muscle
Fatigue and weakness
Dizziness or lightheadedness
Fainting (syncope), especially during or after exercise (due to arrhythmias or reduced blood flow)
Palpitations (feeling of irregular heartbeats)
Sudden cardiac arrest (in rare, severe cases)
Diagnosis of HCM:
HCM is usually diagnosed through a combination of physical examination, family history, and imaging tests:
Echocardiogram (Echocardiography):
This is the primary test for diagnosing HCM. It uses sound waves to produce images of the heart and can show the thickening of the heart walls and assess how well the heart is pumping.
Electrocardiogram (ECG):
An ECG records the electrical activity of the heart and can reveal signs of arrhythmias or other electrical abnormalities associated with HCM.
Cardiac MRI:
In some cases, a cardiac MRI can provide more detailed images of the heart’s structure and help assess the degree of thickening.
Genetic Testing:
Since HCM is genetic, testing for mutations in the heart muscle proteins can help confirm the diagnosis, especially in families with a history of the condition.
Treatment of HCM:
Treatment for HCM depends on the severity of the condition and the presence of symptoms. It may involve medications, lifestyle changes, or surgical procedures.
Medications:
Beta-blockers (e.g., metoprolol, propranolol) are commonly prescribed to help slow the heart rate, reduce symptoms, and lower the risk of arrhythmias.
Calcium channel blockers (e.g., verapamil) can help relax the heart muscle and improve blood flow.
Antiarrhythmic medications may be prescribed if arrhythmias are a concern.
Surgical Procedures:
Septal Myectomy: This is a surgery in which part of the thickened septum (the wall between the ventricles) is removed to relieve the obstruction.
Alcohol Septal Ablation: In cases where surgery is not an option, alcohol may be injected into the small arteries supplying the thickened part of the septum to shrink it and reduce the obstruction.
Implantable Cardioverter-Defibrillator (ICD): For patients at high risk of life-threatening arrhythmias or sudden cardiac arrest, an ICD may be implanted to detect and correct dangerous arrhythmias.
Lifestyle Changes:
People with HCM are typically advised to avoid intense exercise, as it can trigger arrhythmias or other complications.
Maintaining a healthy diet, avoiding excessive alcohol, and managing stress can also help improve overall heart health.
Prognosis:
The prognosis for individuals with HCM can vary. Many people with the condition live relatively normal lives, especially when it is detected early and managed effectively.
The risk of sudden cardiac death (SCD) is higher in individuals with severe forms of the condition, especially if there are symptoms like syncope (fainting) or a family history of sudden death. This is why screening is important, particularly for people with a family history of HCM.
Family Screening:
Since HCM is inherited, family members of a person diagnosed with the condition should undergo screening (typically starting at age 12) to identify whether they are also at risk. This often involves an echocardiogram and ECG.