Hypertrophic cardiomyopathy

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Last reviewed: 14 Apr 2025

Last updated: 01 May 2025

Hypertrophic cardiomyopathy (HCM) is the most common cardiomyopathy and the most frequent cause of sudden cardiac death in young people.

Presentation varies from asymptomatic to symptoms of heart failure.

Physical examination may be normal at rest. Auscultation along the left sternal border when the patient is standing after a brief period of exercise may elicit a murmur.

Family history may be present. Echocardiography should be used to screen first-degree family members.

Has a benign prognosis in the majority of patients.

Medical therapy with beta-blockers or nondihydropyridine calcium-channel blockers is used in symptomatic patients.

A subset of patients with increased risk for sudden death should undergo defibrillator implantation.

Definition

HCM is a genetic disorder characterized by left ventricular hypertrophy that is not solely explained by abnormal loading conditions.[1] It is a common genetic heart disease globally, as well as a common cause of sudden cardiac death in young people.[2] Given its prevalence in younger patients, HCM is frequently confused with athlete's heart. In older patients, HCM may be misdiagnosed as hypertensive heart disease. Many patients will have no symptoms at the time of diagnosis and will be diagnosed following routine examination or family screening of an affected family member.[1][2]

History and exam

Key diagnostic factors

family history of HCM
history of presyncope or syncope
systolic ejection murmur
left ventricular lift (heave)
double apical impulse or double carotid pulsation
family history of sudden death

Full details

Other diagnostic factors

younger male (<50 years)
dyspnea
angina
palpitations
irregularly irregular pulse
older female (>50 years)
collapse
fourth heart sound

Full details

Risk factors

family history of HCM or sudden cardiac death

Full details

Diagnostic tests

1st tests to order

ECG
creatine kinase (CK)
liver function tests
renal function tests
N-terminal pro-brain natriuretic peptide (NT-proBNP)
troponin
urinalysis
CXR
transthoracic echocardiography with Doppler

Full details

Tests to consider

exercise ECG
Holter monitoring
nuclear imaging exercise test
cardiac magnetic resonance (CMR)
cardiac computed tomography (CT)
CT coronary arteriography
cardiac catheterization
stress echocardiography
exercise echocardiography
transesophageal echocardiography
endomyocardial biopsy
genetic mutation analysis

Full details

Treatment algorithm

ONGOING

asymptomatic

symptomatic: left ventricular outflow tract obstruction (LVOTO) with preserved systolic function (ejection fraction ≥50%)

symptomatic: nonobstructive with preserved systolic function (ejection fraction ≥50%)

symptomatic: with systolic dysfunction (ejection fraction <50%)

Contributors

Authors

Theodore Abraham, MD

Professor of Medicine and Radiology

Meyer Friedman Distinguished Professor of Medicine

Co-director, UCSF HCM Center of Excellence

University of California

San Francisco

Disclosures

TA serves as a steering committee member/local investigator and his institution has received research funding for hypertrophic cardiomyopathy-related clinical trials sponsored by Bristol Myers Squibb; Cytokinetics Inc.; Tenaya Pharmaceuticals; and Imbria Pharmaceuticals.

Acknowledgements

Dr Theodore Abraham would like to gratefully acknowledge Dr Monica Mukherjee, Dr Melanie D. Everitt, and Dr Anji T. Yetman, previous contributors to this topic.

Disclosures

MM, MDE, and ATY declare that they have no competing interests.

Peer reviewers

Radhika Kuna, MD

Fellow

Division of Cardiology

University of Maryland Medical Center

Baltimore

Disclosures

RK declares that she has no competing interests.

Saidi Mohiddin, BSc, MBChB

Consultant Cardiologist/Head of Unit

Heart Muscle Disease Unit

Barts and The London NHS Trust

London

Disclosures

SM declares that he has no competing interests.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Arbelo E, Protonotarios A, Gimeno JR, et al. 2023 ESC Guidelines for the management of cardiomyopathies. Eur Heart J. 2023 Oct 1;44(37):3503-626.Full text Abstract

Writing Committee Members, Ommen SR, Ho CY, et al. 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR guideline for the management of hypertrophic cardiomyopathy: a report of the American Heart Association/American College of Cardiology Joint Committee on clinical practice guidelines. J Am Coll Cardiol. 2024 Jun 11;83(23):2324-405.Full text Abstract

Richard P, Charron P, Carrier L, et al. Hypertrophic cardiomyopathy: distribution of disease genes, spectrum of mutations, and implications for a molecular diagnosis strategy. Circulation. 2003 May 6;107(17):2227-32. [Erratum in: Circulation. 2004 Jun 29;109(25):3258.]Full text Abstract

O'Mahony C, Jichi F, Pavlou M, et al. A novel clinical risk prediction model for sudden cardiac death in hypertrophic cardiomyopathy (HCM risk-SCD). Eur Heart J. 2014 Aug 7;35(30):2010-20.Full text Abstract

Pelliccia A, Sharma S, Gati S, et al. 2020 ESC guidelines on sports cardiology and exercise in patients with cardiovascular disease. Eur Heart J. 2021 Jan 1;42(1):17-96.Full text Abstract

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials
- Athlete's heart
- Discrete subaortic stenosis
- LVH due to hypertension
More Differentials
Guidelines
- 2024 AHA/ACC/AMSSM/HRS/PACES/SCMR guideline for the management of hypertrophic cardiomyopathy
- 2023 ESC Guidelines for the management of cardiomyopathies
More Guidelines
Videos
Fourth heart sound gallop
More videos
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Hypertrophic cardiomyopathy

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic tests

1st tests to order

Tests to consider

Treatment algorithm

asymptomatic

symptomatic: left ventricular outflow tract obstruction (LVOTO) with preserved systolic function (ejection fraction ≥50%)

symptomatic: nonobstructive with preserved systolic function (ejection fraction ≥50%)

symptomatic: with systolic dysfunction (ejection fraction <50%)

Contributors

Authors

Theodore Abraham, MD

Disclosures

Acknowledgements

Disclosures

Peer reviewers

Radhika Kuna, MD

Disclosures

Saidi Mohiddin, BSc, MBChB

Disclosures

References

Key articles

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials

Guidelines

Videos

Log in or subscribe to access all of BMJ Best Practice

Log in or subscribe to access all of BMJ Best Practice

Log in to access all of BMJ Best Practice