Understanding Hypertrophic Cardiomyopathy: Symptoms, Causes, Diagnosis, and Treatment Options

Creator: Doctronic
Published: 2023-12-10

Medically reviewed by Alan Lucks | MD, Alan Lucks MDPC Private Practice - New York on December 10th, 2023.

Key Takeaways

The condition primarily affects the interventricular septum, which can thicken to over 15mm (normal is 6-10mm), potentially blocking the left ventricular outflow tract in 70% of cases.
Over 1,400 genetic mutations have been identified as causes, with sarcomere protein genes (MYH7, MYBPC3) accounting for 60% of familial cases passed through autosomal dominant inheritance.
Sudden cardiac death risk is highest in patients under 30 with family history, unexplained syncope, or ventricular wall thickness exceeding 30mm—annual risk ranges from 0.5-1% in adults.
Beta-blockers like metoprolol (25-200mg daily) and calcium channel blockers such as verapamil improve filling by slowing heart rate, while vasodilators and digoxin are contraindicated as they worsen obstruction.
Septal myectomy removes 2-5 grams of muscle tissue and reduces outflow gradient by 90%, while alcohol septal ablation offers a less invasive alternative with 85% symptom improvement rates.

Hypertrophic cardiomyopathy (HCM) is a condition that causes the heart muscle to become thicker than normal, most commonly at the septum between the ventricles, below the aortic valve. This thickening can lead to stiffening of the heart walls and abnormal heart valve function, which may affect blood flow out of the heart.

Symptoms of Hypertrophic Cardiomyopathy

Many people with HCM have no symptoms or only minor symptoms and can live a normal life. However, some people may develop symptoms that worsen as heart function deteriorates. Symptoms of HCM can occur at any age and may include:

Chest pain or pressure, especially with exercise or physical activity
Shortness of breath (dyspnea), particularly with exertion
Fatigue (feeling overly tired)
Fainting (syncope) due to irregular heart rhythms or abnormal blood vessel responses during exercise
Palpitations (fluttering in the chest) caused by abnormal heart rhythms (arrhythmias)
Sudden death (occurs in a small number of patients with HCM)

Causes of Hypertrophic Cardiomyopathy

HCM can be inherited, running in families, but it can also be acquired as a part of aging or high blood pressure. In some cases, the cause is unknown.

Understanding Hypertrophic Cardiomyopathy: Symptoms, Causes, Diagnosis, and Treatment Options

Diagnosing Hypertrophic Cardiomyopathy

To diagnose HCM, doctors consider the patient's medical history, including symptoms and family history, and perform a physical exam. An echocardiogram is a key tool in diagnosing HCM. Additional tests may include:

Blood tests
Electrocardiogram (ECG)
Chest X-ray
Exercise stress test
Cardiac catheterization
CT scan
MRI

Treating Hypertrophic Cardiomyopathy

Treatment for HCM depends on several factors, including the presence of outflow tract narrowing, heart function, and the presence of arrhythmias. The goals of treatment are to prevent symptoms and complications through risk identification, regular follow-up, lifestyle changes, medications, and procedures when necessary.

Lifestyle Changes

Maintain adequate hydration, unless fluid restriction is advised by a doctor
Follow specific fluid and dietary guidelines provided by a doctor, including information about alcohol and caffeine consumption
Engage in non-competitive aerobic exercise, if approved by a doctor
Attend regular follow-up visits with a cardiologist to monitor the condition

Medications

Medications can help relax the heart, reduce obstruction, and improve heart function. Beta-blockers and calcium channel blockers are commonly prescribed. Arrhythmia medications may be used to control heart rate and reduce the occurrence of abnormal heart rhythms. Some medications, such as nitrates and digoxin, should be avoided as they can lower blood pressure or increase the force of the heart's contraction.

Procedures

Septal myectomy: A surgical procedure to remove a small portion of the thickened septal wall, widening the outflow tract from the left ventricle to the aorta
Ethanol ablation: A minimally invasive procedure that involves injecting a small amount of alcohol into the coronary artery supplying blood to the septum, causing the thickened area to shrink
Implantable Cardioverter Defibrillators (ICD): Devices that monitor heart rhythm and deliver energy to the heart muscle to restore normal rhythm when life-threatening arrhythmias are detected

Hypertrophic Cardiomyopathy and Sudden Death

A small number of people with HCM have an increased risk of sudden cardiac death. Risk factors include a family history of sudden cardiac death, young age, episodes of fainting, abnormal blood pressure response during exercise, a history of fast heart rate arrhythmias, and severe symptoms with poor heart function. If you have two or more risk factors, your doctor may prescribe medications or an ICD to prevent arrhythmias.

Preventing Endocarditis

People with obstructive HCM may have a higher risk of infective endocarditis, a serious condition. To prevent endocarditis, take the following precautions:

Inform all your doctors and dentists about your HCM diagnosis
Take antibiotics before any procedures that may cause bleeding, as prescribed by your doctor
Contact your doctor if you experience symptoms of an infection
Maintain good oral hygiene

For more information about hypertrophic cardiomyopathy, visit the following reputable sources:

The Bottom Line

Most patients live normal lives with proper medication and activity restrictions, though genetic counseling is recommended for family members since each child has a 50% inheritance risk. Regular echocardiograms and stress testing help monitor progression and sudden death risk factors. If you're experiencing unexplained chest pain, shortness of breath during exercise, or have a family history of heart conditions, Doctronic can help evaluate your symptoms quickly.