What's hypertrophic cardiomyopathy?
Hypertrophic cardiomyopathy is a condition in which the heart muscle becomes abnormally thick, most often the wall (septum) between the heart's two main pumping chambers. It is the most common inherited heart-muscle disease and usually runs in families in an autosomal dominant pattern, meaning one altered gene copy can be enough to cause it. The genes most often involved build the sarcomere, the heart muscle's contracting unit; MYBPC3 and MYH7 are the two most frequently affected.
| Also indexed as | OMIM:192600, MONDO:0008647 |
|---|---|
| Features mapped | 11 |
| Treatments mapped | 5 |
| Published sources | 14 |
| Last reviewed | 2026-08-04 |
Signs and symptoms
Congestive heart failure
as treatment has lowered deaths from hypertrophic cardiomyopathy, heart failure (along with atrial fibrillation) has become one of the leading remaining causes of illness and death from the condition. heart failure means the thickened, stiff heart muscle struggles to fill and pump effectively.
Arrhythmia
abnormal heart rhythms (arrhythmias) can occur in hypertrophic cardiomyopathy, alongside reduced exercise tolerance, heart failure, and the risk of sudden cardiac death.
Asymmetric septal hypertrophy
The thickening is often asymmetric, affecting the septum more than the rest of the heart muscle. When the thickened septum blocks blood leaving the heart (left ventricular outflow tract obstruction), it can be present at rest or appear only with exertion, which is why exercise stress testing is sometimes needed to reveal it.
Autosomal dominant inheritance
Hypertrophic cardiomyopathy is usually inherited in an autosomal dominant pattern, so a child of an affected parent has about a 1 in 2 chance of inheriting the altered gene. This is why first-degree relatives are offered screening. Inheriting the gene does not guarantee disease, and severity varies widely between people.
Sudden cardiac death
Hypertrophic cardiomyopathy is a leading cause of sudden cardiac death in young people, including athletes. Much of specialist care centers on estimating each person's individual risk and, for those at higher risk, considering an implantable defibrillator. Most people with the condition are not at high risk, and the decision rests with the care team.
Syncope
Some people have fainting spells (syncope), especially during or just after exertion. Unexplained fainting is one of the warning signs doctors weigh when judging sudden-death risk, and it should be reported promptly.
Myofiber disarray
under the microscope, the heart muscle in hypertrophic cardiomyopathy often shows myofiber disarray, where muscle fibers that should line up in parallel are instead disorganized. it appears alongside features such as asymmetric thickening, outflow obstruction, and atrial fibrillation.
Ventricular hypertrophy
the defining feature of hypertrophic cardiomyopathy is unexplained thickening of the left ventricle, the heart's main pumping chamber, that is not accounted for by another cause such as high blood pressure. it arises from changes in the genes that build the heart muscle's contracting units.
Dyspnea
breathlessness (dyspnea) is one of the most frequent symptoms of hypertrophic cardiomyopathy. in a cohort study it was, along with chest pain, among the most common complaints people reported.
Chest pain
chest pain is one of the most frequent symptoms of hypertrophic cardiomyopathy. in a cohort study it was, along with breathlessness, among the most common complaints people reported.
Atrial fibrillation
Atrial fibrillation, an irregular heart rhythm, is common in hypertrophic cardiomyopathy and raises the risk of stroke, so it is actively looked for and treated, often including blood-thinning medication.
How it is diagnosed
Cardiomyopathy, familial hypertrophic 1
Diagnosed using: echocardiography.
“Current gold-standard diagnostic methods include echocardiography and cardiac magnetic resonance imaging.”
Cardiomyopathy, familial hypertrophic 1
Diagnosed using: cardiac magnetic resonance imaging.
“Current gold-standard diagnostic methods include echocardiography and cardiac magnetic resonance imaging.”
Cardiomyopathy, familial hypertrophic 1
Diagnosed using: genetic testing.
“…the consensus emphasizes a comprehensive diagnostic approach, including imaging and genetic testing, family screening and risk…”
Treatment and management
What the research describes, not a recommendation. Treatment decisions belong with your clinician.
This covers treatments that appear in the published research mapped here. Investigational and experimental therapies are not included, so their absence is a boundary of this map, not a sign they do not exist.
beta-blockers
Beta-blockers are a first-line medicine for hypertrophic cardiomyopathy with obstruction. They slow the heart and ease the obstruction to blood leaving the heart, relieving symptoms such as breathlessness and chest pain. They manage symptoms rather than changing the underlying genetic cause.
Used to help with: Cardiomyopathy, familial hypertrophic 1.
“Conventional pharmacological therapies such as β-blockers and nondihydropyridine calcium channel blockers are effective first-line treatments for obstructive…”
mavacamten
Mavacamten is a newer medicine called a cardiac myosin inhibitor. It calms the heart muscle's overactive contraction, which can reduce or resolve the obstruction to blood leaving the heart and is being used as an alternative when standard medicines are not tolerated. It is started and monitored by a specialist.
Used to help with: Cardiomyopathy, familial hypertrophic 1.
“After shared decision-making, mavacamten was initiated. Follow-up stress imaging demonstrated complete resolution of LVOTO with preserved systolic function.”
septal myectomy
When medicines do not control symptoms from obstruction, procedures that reduce the thickened septum can give effective relief. Surgical septal myectomy removes a small amount of the overgrown muscle; alcohol septal ablation is a catheter-based alternative. These are reserved for people whose symptoms persist despite medication.
Used to help with: Cardiomyopathy, familial hypertrophic 1.
“…established invasive septal reduction therapies, such as surgical myectomy and alcohol septal ablation, provide effective relief of obstruction in refractory…”
implantable cardioverter-defibrillator
an implantable cardioverter-defibrillator (ICD) is a device placed under the skin to prevent sudden cardiac death in hypertrophic cardiomyopathy. it watches the heart rhythm and delivers a shock to restore a normal beat if a dangerous rhythm occurs. it is used for people judged to be at higher risk.
Used to help with: Cardiomyopathy, familial hypertrophic 1.
“…in the prevention of sudden cardiac death, implantable cardiac defibrillators and antiarrhythmic drugs are…”
antiarrhythmic drugs
antiarrhythmic drugs are medicines used in hypertrophic cardiomyopathy to help prevent sudden cardiac death by controlling dangerous heart rhythms. they are used alongside other measures rather than changing the underlying genetic cause.
Used to help with: Cardiomyopathy, familial hypertrophic 1.
“…in the prevention of sudden cardiac death, implantable cardiac defibrillators and antiarrhythmic drugs are…”
How to read the evidence labels
Where this comes from
This guide is built from 14 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.
Take it further
Printed, source-linked documents built from this condition's graph — ready to bring to an appointment or attach to a coverage request. Every claim carries its published source, the same as this guide.