Diagnosis guide for clinicians
Hypertrophic cardiomyopathy: when to suspect it and what to test
Hypertrophic cardiomyopathy (HCM) is the most common heritable cardiomyopathy, with an estimated prevalence of 1 in 200 to 1 in 500, and is defined by left ventricular hypertrophy that is not the result of secondary causes, a 2026 Mayo Clinic review in BMJ Medicine says.Source Mayo Clinic review (Gilreath 2026)
Evaluation is often prompted by symptoms or a heart murmur, or by an abnormal ECG or imaging result obtained for another reason, and about 70% of patients have outflow tract obstruction at rest or with provocation.
Source Mayo Clinic review (Gilreath 2026)In US insurance claims for 3888 patients with obstructive HCM, 59.5% carried another diagnosis indicating a misdiagnosis in the 24 months before the definitive diagnosis, with a mean of 4.0 such diagnoses; 2 of the 7 authors worked for MyoKardia, a Bristol Myers Squibb subsidiary.
Source US claims study of delay (Naidu 2023)- Also called
NON RARE IN EUROPE: Familial isolated hypertrophic obstructive cardiomyopathy, NON RARE IN EUROPE: Familial isolated hypertrophic subaortic stenosis, NON RARE IN EUROPE: Familial or idiopathic hypertrophic subaortic stenosis and 4 more
NON RARE IN EUROPE: Familila or idiopathic hypertrophic obstructive cardiomyopathy, NON RARE IN EUROPE: Hypertrophic obstructive cardiomyopathy, NON RARE IN EUROPE: Primitive hypertrophic obstructive cardiomyopathy, NON RARE IN EUROPE: Primitive hypertrophic subaortic stenosis
Live from Orphanet (INSERM) via Orphadata, licensed CC BY 4.0, data version 2026-06-23.
Patterns that should prompt a test for Hypertrophic cardiomyopathy
Each sign below is common on its own, which is why Hypertrophic cardiomyopathy is missed. Published studies describe these combinations as the picture to act on. Rows are ordered from the highest published figure to the lowest, within each kind of measure.
Where testing finds it
Share of each screened or biopsied group found to have Hypertrophic cardiomyopathy, from the cited studies. A bar spans the lowest to the highest published figure.
- 1
Relative who carries the family's pathogenic variant+ECG and echocardiogram at cascade testing
273 relatives found to carry the family variant in a 2025 cascade testing study cited by a Mayo Clinic review
HCM was diagnosed at evaluation in 128 of 273 (47%); the other 145 (53%) were genotype-positive without the phenotype (Gilreath 2026).Mayo Clinic review (Gilreath 2026)
- 2
First-degree or other relative of a patient with HCM+ECG, echocardiogram and genetic testing at one screening visit
1230 relatives from 531 families screened at inherited cardiomyopathy clinics in Eastern Denmark, 2006 to 2023
The combined clinical and genetic yield at baseline was 26% (321 relatives); 43 more (4%) developed HCM over a mean 7 years of follow-up (Silajdzija 2024).Danish family screening (Silajdzija 2024)
- 3
Child with a first-degree relative with HCM+Serial ECG and echocardiogram, by family genotype
404 children from 227 genotype-positive families and 292 children from 170 genotype-negative families referred for screening to a London center
The 5-year cumulative incidence of a diagnosis was 11.1% in genotype-positive families and 4.0% in genotype-negative families; a diagnosis was made in 18.1% and 8.2% of families (Norrish 2026).Norrish 2026
- 4
Child with a first-degree relative with HCM+Serial ECG and echocardiogram
1198 consecutive children aged 18 or younger from 594 families screened at a London center, 1994 to 2017
Almost 5% met diagnostic criteria at first or later evaluations (32 at baseline and 25 during follow-up), at a median age of 10 years; a diagnosis was made in 8% of families (Norrish 2019).Norrish 2019
- 5
Echocardiogram in a young adult from the general population+Wall thickness of 15mm or more without hypertension
4111 men and women aged 23 to 35 from 4 urban centers in the CARDIA study, 1987 to 1988
Probable or definite HCM was found in 7 (0.17%); only 1 of the 7 had been suspected of cardiovascular disease, and ECGs were abnormal in 5 of the 7 (Maron 1995).CARDIA study (Maron 1995)
How often diagnosed patients show it
Share of patients already diagnosed who had the finding, in the group named on each row. Groups differ by age and type, so read each row with its group.
- 1
Unexplained wall thickening+Repolarization changes or hypertrophy voltage on ECG
682 patients with HCM by ESC criteria at an Istanbul center, and a Mayo Clinic series of 135 patients with a normal ECG and 2350 with an abnormal ECG
Repolarization changes were present in 82.6% and hypertrophy voltage criteria in 70.2%; 1.6% had a completely normal ECG (Guler 2026), as did almost 6% in the Mayo Clinic series (McLeod 2009).Guler 2026
- 2
Unexplained wall thickening+Outflow gradient at rest or after exercise
320 consecutive patients with HCM studied at rest, with Valsalva and with exercise echocardiography
Obstruction was present at rest or with exercise in 225 (70%); 119 had resting gradients of 50mmHg or more (Maron 2006).Maron 2006
- 3
Wall thickening on cardiac MRI+Late gadolinium enhancement
People with HCM in the studies summarized by a 2026 Mayo Clinic review
Some degree of late gadolinium enhancement is present in approximately 60% (Gilreath 2026).Mayo Clinic review (Gilreath 2026)
- 4
Another cardiovascular diagnosis in the previous 2 years+Obstructive HCM on the definitive work-up
3888 patients with obstructive HCM in US commercial and Medicare supplemental claims, 2009 to 2019, in a study with MyoKardia-employed authors
A delay marked by an alternative diagnosis was found in 59.5%, with a mean of 4.0 such diagnoses; 78.4% had seen a cardiologist first (Naidu 2023).US claims study of delay (Naidu 2023)
- 5
Resting outflow gradient under 50mmHg+Exercise echocardiography
201 of the 320 consecutive patients, those with resting gradients under 50mmHg
Obstruction developed after exercise in 106 of 201 (53%, our division of the reported counts), including 76 with gradients of 50mmHg or more; Valsalva underestimated it (Maron 2006).Maron 2006
- 6
Woman with HCM+Outflow obstruction
969 consecutive patients with HCM from Italy and the US, 59% of them men
Obstruction was found in 37% of women against 23% of men; women were older at first evaluation (47 against 38 years) and less often diagnosed on routine examination (23% against 41%) (Olivotto 2005).Olivotto 2005
- 7
Clinical HCM+Pathogenic or likely pathogenic sarcomere variant on a gene panel
2912 unrelated probands tested at one referral laboratory over 10 years, and 818 patients referred to 4 European centers
The detection rate was about 32% with a further 15% inconclusive (Alfares 2015), and 39% in the European cohort (Maurizi 2025); a Mayo Clinic review gives 30% to 40% (Gilreath 2026).Alfares 2015
- 8
Hypertension on the problem list+Wall thickening that meets HCM criteria
2873 consecutive patients with HCM referred for cardiac MRI in a French multicenter registry, 2008 to 2024
Hypertension was present in 796 (28%) (Florence 2026).Florence 2026
- 9
Palpitations or an irregular pulse+Atrial fibrillation
Patients with HCM in the studies summarized by a 2026 Mayo Clinic review
Atrial fibrillation is present in 18% of patients with HCM, against about 4% of all American adults (Gilreath 2026).Mayo Clinic review (Gilreath 2026)
- 10
Syncope+Unexplained wall thickening
21,791 people with HCM in a 2022 study cited by a Mayo Clinic review
A syncopal episode occurred in 3452 (15.8%) over 5.6 years (Gilreath 2026).Mayo Clinic review (Gilreath 2026)
Also described, without a comparable figure
- Athlete with wall thickness of 13 to 15mm + Left ventricular cavity under 54mm: No frequency in unselected athletes was found; in this matched comparison of 53 people, a cavity under 54mm distinguished HCM from athlete's heart with 100% sensitivity and specificity, and absence of diffuse T-wave inversion had 92% specificity for excluding HCM (Caselli 2014).Caselli 2014
- HCM picture with no sarcomere variant + Diagnosis before age 20 or after age 60: Non-sarcomeric patients were diagnosed before age 20 or after age 60 in 476 of 500 (95%); physical examination red flags were almost exclusive to non-sarcomeric causes, 348 of 350 (Maurizi 2025).European red flag study (Maurizi 2025)
- HCM label in a patient aged 40 or older + Cardiac amyloidosis on further work-up: Cardiac amyloidosis was diagnosed in 32 (9%), from 1 of 75 (1%) at ages 40 to 49 to 8 of 31 (26%) at age 80 or older (Maurizi 2020).Maurizi 2020
- Left ventricular hypertrophy or an HCM label + Pathogenic GLA variant (Fabry disease): The pooled prevalence of Fabry disease was 1.2% using American College of Medical Genetics and Genomics criteria (Monda 2023).Fabry screening meta-analysis (Monda 2023)
- HCM label + Clinical skeletal myopathy + LAMP2 mutation (Danon disease): LAMP2 mutations were found in 2 of 197 (1%), or 2 of 50 sequenced (4%); Danon disease explained 2 of 4 cases with skeletal myopathy and none of 41 with isolated HCM (Charron 2004).Charron 2004
- Wall thickness of 13 to 14mm + First-degree relative with HCM or a pathogenic sarcomere variant: No frequency for this combination was found; the guideline says this more limited hypertrophy can be diagnostic in family members or with a positive genetic test (Sanghvi 2025).Guideline systematic review (Sanghvi 2025)
- Unexplained anterolateral T-wave inversion + Normal routine echocardiogram without contrast: No screening yield was found for this combination; all 10 in this selected series had apical HCM on cardiac MRI, with wall thickness up to 28mm (Moon 2004).Moon 2004
- Left ventricular hypertrophy + Short PR interval or pre-excitation: No frequency for this combination was found; ANMCO lists it as a pointer to Fabry disease, Danon disease, PRKAG2 disease and other storage or mitochondrial disease rather than sarcomeric HCM (ANMCO 2025).ANMCO position paper 2025
- Wall thickening in an older adult + Low QRS voltage for the degree of thickening + Carpal tunnel syndrome: No frequency for this combination was found; ANMCO lists old age at onset, low voltages and carpal tunnel syndrome as red flags for amyloidosis (ANMCO 2025).ANMCO position paper 2025
These figures describe published study groups. They are not the chance that any one patient has Hypertrophic cardiomyopathy, and bars whose ranges overlap are not in a settled order.
Red flags for Hypertrophic cardiomyopathy
What the cited sources describe, grouped by life stage and organ. Each line links to its source.
Symptoms and history
- Chest pain, exertional dyspnea, fatigue, palpitations, and syncope at rest or with exertion are the cardiac symptoms the Mayo Clinic review says should be asked about, along with any history of cardiac arrest.Mayo Clinic review (Gilreath 2026)
- Dyspnea on exertion is one of the main symptoms and may typically be accentuated after meals, an Italian cardiology society (ANMCO) position paper notes.ANMCO position paper 2025
- Syncope is common: the Mayo Clinic review cites a 2022 study in which 3452 of 21,791 people with HCM (15.8%) had a syncopal episode over 5.6 years.Mayo Clinic review (Gilreath 2026)
- Atrial fibrillation is present in 18% of patients with HCM, compared with about 4% of all American adults, according to the same review.Mayo Clinic review (Gilreath 2026)
- Anatomical and clinical manifestations often appear by the late teens or early twenties, but diagnosis can occur at any age and may be delayed.Mayo Clinic review (Gilreath 2026)
- Median age at diagnosis was 45.8 years among 4591 patients followed at 8 international HCM specialty centers in the SHaRe registry, which is funded by an unrestricted research grant from MyoKardia.SHaRe registry (Ho 2018)
Examination
- Obstructive HCM produces a harsh systolic murmur that swells and fades, often loudest along the left sternal border.Mayo Clinic review (Gilreath 2026)
- The murmur grows louder with reductions in preload or afterload, such as the Valsalva maneuver or standing from a squatting position.Mayo Clinic review (Gilreath 2026)
- Repeated squat-to-stand movements (5 to 20 repetitions) at the bedside can be quite sensitive for provoking a dynamic obstruction when other maneuvers fail, the Mayo Clinic authors write.Mayo Clinic review (Gilreath 2026)
- Brisk carotid upstrokes help separate HCM from valvular or fixed subvalvular aortic stenosis; a prominent apical impulse and a fourth heart sound may also be found.Mayo Clinic review (Gilreath 2026)
- A separate apical murmur of mitral regurgitation from systolic anterior motion of the mitral valve may accompany the outflow murmur, and the two are often hard to tell apart.Mayo Clinic review (Gilreath 2026)
ECG
- The 12-lead ECG is abnormal in about 90% of patients with HCM; the most common findings are voltage criteria for left ventricular hypertrophy and repolarization abnormalities, including deep lateral T-wave inversions.Mayo Clinic review (Gilreath 2026)
- Widespread deep Q waves and pre-excitation are additional ECG findings consistent with HCM.Mayo Clinic review (Gilreath 2026)
- Among 682 patients at an Istanbul center, repolarization changes were present in 82.6% and voltage criteria for hypertrophy in 70.2%; 11 (1.6%) had a completely normal ECG.Guler 2026
- ANMCO notes that an abnormal ECG may be the only sign of disease at an early stage, and that T-wave inversion in the lateral leads is typical of HCM with mainly apical hypertrophy.ANMCO position paper 2025
Echocardiography and MRI
- The 2024 AHA/ACC guideline criterion in adults, as reproduced in a 2025 systematic review of guidelines, is a maximal end-diastolic wall thickness of 15mm or more anywhere in the left ventricle, in the absence of another cause of hypertrophy.Guideline systematic review (Sanghvi 2025)
- Asymmetric septal hypertrophy is the most frequent pattern, but hypertrophy can occur in any distribution and with varied severity.Mayo Clinic review (Gilreath 2026)
- Systolic anterior motion of the mitral valve with a late-peaking, dagger-shaped continuous wave Doppler signal marks dynamic outflow obstruction.Mayo Clinic review (Gilreath 2026)
- In 320 consecutive patients, obstruction was present at rest or with exercise in 225 (70%); 95 (30%) had no or small gradients (under 30mmHg) both at rest and with exercise.Maron 2006
- Late gadolinium enhancement on cardiac MRI, which marks replacement fibrosis, is present to some degree in about 60% of people with HCM.Mayo Clinic review (Gilreath 2026)
- Apical HCM, hypertrophy confined mainly to the apex, is more common in people of Asian ethnicity and in men, and is linked to mid-ventricular obstruction and apical aneurysms.Mayo Clinic review (Gilreath 2026)
Family history
- A 3-generation family history is advised to find relatives with known HCM and clues to undiagnosed HCM, such as a heart murmur or sudden death.Mayo Clinic review (Gilreath 2026)
- HCM is inherited within families in an autosomal dominant pattern, with incomplete penetrance and variable expression; non-familial HCM also occurs.Mayo Clinic review (Gilreath 2026)
- Among 1230 relatives from 531 families screened in Eastern Denmark, the combined clinical and genetic yield of the first screening visit was 26% (321 relatives).Danish family screening (Silajdzija 2024)
Women, children and athletes
- Women were older than men at first evaluation (47 against 38 years), more symptomatic, more often obstructed (37% against 23%) and less often diagnosed by chance on routine examination (23% against 41%) among 969 patients in Italy and the US.Olivotto 2005
- In an international registry of 5873 patients at experienced HCM centers, women were 3.6 to 7.1 years older at diagnosis, except those with MYH7 variants.Lakdawala 2021
- Among 1198 children screened at a London center after a first-degree relative was diagnosed, almost 5% met diagnostic criteria at first or later evaluations, at a median age of 10 years.Norrish 2019
- A wall thickness of 13mm or more was found in only 16 of 947 elite athletes (1.7%), the thickest wall measured 16mm, and all 16 had enlarged left ventricular cavities.Pelliccia 1991
Clues that point to a mimic instead
- Development of left ventricular hypertrophy in childhood and signs of disease outside the heart should raise suspicion of a genetic mimic, the Mayo Clinic review says.Mayo Clinic review (Gilreath 2026)
- In 818 patients with a clinical HCM diagnosis at 4 European centers, physical examination red flags were seen almost only in those with a definite non-sarcomeric cause (348 of 350), and 95% of non-sarcomeric patients were diagnosed before age 20 or after age 60.European red flag study (Maurizi 2025)
- ANMCO lists a short PR interval with hypertrophy as a pointer to Fabry disease, and a short PR interval or pre-excitation as common in Danon disease, PRKAG2 disease, Pompe disease and mitochondrial disease.ANMCO position paper 2025
- Low QRS voltage relative to the degree of wall thickening, carpal tunnel syndrome, pericardial effusion and valve thickening are listed by ANMCO as pointers to amyloidosis.ANMCO position paper 2025
- Raised transaminases or creatine kinase, muscle weakness and intellectual disability are among ANMCO's red flags for Danon disease.ANMCO position paper 2025
- In the European study, RASopathies and inherited metabolic and mitochondrial disorders were diagnosed at a mean age of 3 years, and Danon disease, Friedreich ataxia, Noonan syndrome and PRKAG2 cardiomyopathy mostly in adolescence (mean age 16).European red flag study (Maurizi 2025)
Hypertrophic cardiomyopathy is often mistaken for
Diagnoses patients commonly carry first, and why the sources say they are confused.
| First diagnosis | Why it is confused |
|---|---|
| Other cardiovascular diagnoses in the 2 years before | In the US claims study with MyoKardia-employed authors, most of the mean 4.0 earlier diagnoses were other cardiovascular conditions; 78.4% of patients had seen a cardiologist before the definitive diagnosis, and the authors estimate 15.7% may have received inappropriate treatment.US claims study of delay (Naidu 2023) |
| Hypertensive heart disease | Longstanding, poorly controlled hypertension can produce hypertrophy resembling HCM. The Mayo Clinic review lists features favoring HCM: systolic anterior motion, wall thickness of 18mm or more, hypertrophy mainly of the apex, anterolateral free wall or posterior septum, and prominent or diffuse late gadolinium enhancement.Mayo Clinic review (Gilreath 2026) |
| Athlete's heart | Training can thicken the wall, particularly in Black athletes and in strength and power sports. Features favoring HCM include wall thickness of 15mm or more, a normal or small cavity, systolic anterior motion, diastolic dysfunction, outflow obstruction and late gadolinium enhancement away from the right ventricular insertion points.Mayo Clinic review (Gilreath 2026) |
| Aortic stenosis or a subaortic membrane | Valvular aortic stenosis and supravalvular or subvalvular membranes raise afterload and cause hypertrophy that can resemble HCM. Obstruction in HCM is dynamic, unlike these fixed lesions, and brisk carotid upstrokes are a differentiator, the Mayo Clinic review says.Mayo Clinic review (Gilreath 2026) |
| Cardiac amyloidosis (labeled HCM) | Among 343 patients aged 40 or older referred to Italian cardiomyopathy centers with an initial HCM diagnosis, 32 (9%) had cardiac amyloidosis, rising from 1% at ages 40 to 49 to 26% at age 80 or older.Maurizi 2020 |
| Fabry disease (labeled HCM) | A meta-analysis pooled a 1.2% prevalence of Fabry disease across 26 studies and 10,080 patients with left ventricular hypertrophy or HCM, using American College of Medical Genetics and Genomics variant criteria.Fabry screening meta-analysis (Monda 2023) |
| Danon disease (labeled HCM) | LAMP2 mutations were found in 2 of 197 index cases with HCM in Paris (1%), both with severe heart failure before age 25; Danon disease explained 2 of 4 cases with clinical skeletal myopathy and none of 41 with isolated HCM.Charron 2004 |
| Pompe disease, mitochondrial disease, RASopathies and Friedreich ataxia | The Mayo Clinic review names these among the storage, metabolic and syndromic mimics, and says hypertrophy that develops in childhood and signs outside the heart should raise suspicion.Mayo Clinic review (Gilreath 2026) |
| PRKAG2 disease | ANMCO describes an autosomal dominant condition causing hypertrophy, pre-excitation and arrhythmia; its red flag table links pre-excitation, atrioventricular block, raised creatine kinase and massive hypertrophy to it.ANMCO position paper 2025 |
| A normal heart, after a normal routine echocardiogram | Ten patients with unexplained anterolateral T-wave inversion and a normal routine echocardiogram without contrast all had apical HCM on cardiac MRI, with wall thickness up to 28mm.Moon 2004 |
Codes patients often carry before this diagnosis
For spotting the pattern in a problem list or registry. Descriptions are checked daily against NLM's ICD-10-CM service; this is not coding advice.
R01.1Detection of a heart murmur is one of the usual prompts for evaluation, and the obstructive murmur changes with Valsalva and standing.Mayo Clinic review (Gilreath 2026)
R55A 2022 study cited by the Mayo Clinic review found syncope in 15.8% of 21,791 people with HCM over 5.6 years.Mayo Clinic review (Gilreath 2026)
R94.31The ECG is abnormal in about 90% of patients, and an abnormal ECG obtained for another reason can be the first clue.Mayo Clinic review (Gilreath 2026)
R06.00, R07.9, R00.2Exertional dyspnea, chest pain and palpitations are the cardiac symptoms the review lists.Mayo Clinic review (Gilreath 2026)
I11.9In a French registry of 2873 patients with HCM, 28% also had hypertension, so the two labels overlap.Florence 2026
I35.0Valvular aortic stenosis causes hypertrophy that can resemble HCM; a brisk carotid upstroke helps separate the two.Mayo Clinic review (Gilreath 2026)
I48.91Atrial fibrillation is present in 18% of patients with HCM.Mayo Clinic review (Gilreath 2026)
Z82.41Sudden death in a relative is a clue to undiagnosed HCM in the family and part of the guideline's risk assessment.Mayo Clinic review (Gilreath 2026)
Testing for Hypertrophic cardiomyopathy, step by step
The testing order the cited guidance describes, by who it applies to. It summarizes published guidance and is not a plan for any one patient.
Anyone with a compatible symptom, murmur, ECG or imaging finding, or an affected relative
- Family history, symptoms and risk history
The Mayo Clinic review advises a 3-generation family history and questions about chest pain, exertional dyspnea, palpitations, syncope and cardiac arrest. A history of poorly controlled hypertension or signs of systemic disease may suggest a mimic.Mayo Clinic review (Gilreath 2026)
Patients with a systolic murmur or suspected obstruction
- Examination with provocative maneuvers
The systolic murmur of obstructive HCM increases with the Valsalva maneuver and on standing from a squat. The review describes 5 to 20 repeated squat-to-stand movements as quite sensitive when other maneuvers fail.Mayo Clinic review (Gilreath 2026)
All patients with suspected HCM, and relatives being screened
- 12-lead ECG
Abnormal in about 90% of patients. Typical findings are voltage criteria for left ventricular hypertrophy, deep lateral T-wave inversions, widespread deep Q waves and pre-excitation.Mayo Clinic review (Gilreath 2026)
All patients with suspected HCM
- Transthoracic echocardiogram
As reproduced in a 2025 systematic review of guidelines, the 2024 AHA/ACC guideline recommends a transthoracic echocardiogram in the initial evaluation (class 1). Its adult criterion is wall thickness of 15mm or more anywhere in the left ventricle without another cause; 13 to 14mm can be diagnostic in family members of a patient with HCM or with a pathogenic or likely pathogenic variant.Guideline systematic review (Sanghvi 2025)
All patients having the echocardiogram
- Doppler outflow gradient
Gradients are measured with continuous wave Doppler. Obstruction is defined by a gradient of at least 30mmHg, and at least 50mmHg is generally considered the level needed to cause symptoms. The gradient can vary within minutes and with time of day, position and meals.Mayo Clinic review (Gilreath 2026)
Patients whose resting peak outflow gradient is under 50mmHg
- Provocation for outflow obstruction
As reproduced in a 2025 systematic review of guidelines, the 2024 AHA/ACC guideline recommends an echocardiogram with provocative maneuvers when the resting peak gradient is under 50mmHg, and exercise echocardiography for symptomatic patients with no resting or provocable gradient of 50mmHg or more (both class 1). The 2023 ESC guideline specifies Valsalva in the sitting and semi-supine positions, then standing if no gradient is provoked.Guideline systematic review (Sanghvi 2025)
Inconclusive echocardiography, or suspicion of another cause of hypertrophy
- Cardiac MRI
As reproduced in a 2025 systematic review of guidelines, the 2024 AHA/ACC guideline indicates cardiac MRI when echocardiography is inconclusive and calls it useful when infiltrative or storage disease or athlete's heart is suspected (both class 1). The 2023 ESC guideline goes further and recommends contrast-enhanced MRI at initial evaluation for all patients.Guideline systematic review (Sanghvi 2025)
Patients under 18
- Wall thickness z-scores in children
Diagnosis rests on wall thickness, family history and genetic testing: at least 2 standard deviations above the mean with a positive family history or genetic test, or at least 2.5 standard deviations without them.Mayo Clinic review (Gilreath 2026)
Atypical presentations, childhood onset, onset after 60, or signs outside the heart
- Work-up for mimics
As reproduced in a 2025 systematic review of guidelines, the 2024 AHA/ACC guideline recommends a work-up that includes genetic testing for HCM and for other genetic causes of unexplained hypertrophy when the presentation is atypical or another genetic condition is suspected (class 1).Guideline systematic review (Sanghvi 2025)
Patients who meet criteria for HCM
- Genetic counseling and testing
Genetic testing is not required for the diagnosis, but guidelines recommend genetic counseling and offering testing. An identified pathogenic variant helps find family members at risk. Panels usually cover sarcomere genes and genes for mimics; a pathogenic or likely pathogenic variant is found in 30% to 40% of patients.Mayo Clinic review (Gilreath 2026)
All patients with HCM, at first evaluation and every 1 to 2 years
- Sudden death risk assessment
As reproduced in a 2025 systematic review of guidelines, the 2024 AHA/ACC guideline recommends a systematic noninvasive assessment (class 1) covering personal history of cardiac arrest or sustained ventricular arrhythmia, syncope suspected to be arrhythmic, premature HCM-related sudden death, cardiac arrest or sustained ventricular arrhythmia in a close relative, maximal wall thickness, ejection fraction, apical aneurysm, and nonsustained ventricular tachycardia on ambulatory monitoring. Cardiac MRI is recommended when risk remains uncertain.Guideline systematic review (Sanghvi 2025)
Symptomatic obstructive HCM being considered for mavacamten (Camzyos)
- Echocardiogram before a cardiac myosin inhibitor
The Camzyos label requires echocardiogram assessments of left ventricular ejection fraction before and during treatment, does not recommend starting when ejection fraction is under 55%, and limits supply to a REMS program. Dosing follows ejection fraction and the Valsalva outflow gradient.Camzyos label
Where testing goes wrong
- A resting echocardiogram alone can miss obstruction: of 201 patients with resting gradients under 50mmHg, 106 developed obstruction after exercise, and the Valsalva maneuver underestimated exercise-induced obstruction.Maron 2006
- A normal ECG does not exclude HCM. Almost 6% of Mayo Clinic patients with echocardiographic HCM had a normal ECG at diagnosis; they had a less severe phenotype than the 2350 with an abnormal ECG.McLeod 2009
- The Istanbul authors, who found a completely normal ECG in 1.6% of 682 patients, conclude that a normal ECG substantially lowers the likelihood of HCM but does not exclude it.Guler 2026
- Obstruction without systolic anterior motion of the mitral valve should raise suspicion of a subaortic membrane, ANMCO notes.ANMCO position paper 2025
- A normal routine echocardiogram without contrast does not exclude apical HCM in a patient with unexplained repolarization abnormalities; the authors of a 10-patient series advise cardiac MRI or contrast echocardiography.Moon 2004
- The 15mm threshold is not adjusted for ethnicity, sex or body size. The guideline review notes that women have a wall 1 to 2mm thinner than men, and that the tapering apex needs relatively more hypertrophy to reach 15mm.Guideline systematic review (Sanghvi 2025)
- Systolic anterior motion is not unique to HCM. It is also seen in Fabry disease and cardiac amyloidosis, in critical illness with catecholamine excess, and during dobutamine stress testing.Mayo Clinic review (Gilreath 2026)
- ANMCO states that dobutamine is contraindicated for provoking a gradient; it names the Valsalva maneuver, moving from lying to standing, squatting and exercise instead.ANMCO position paper 2025
- Hypertension and HCM coexist. In a French multicenter registry of 2873 patients with HCM referred for cardiac MRI, 796 (28%) had hypertension.Florence 2026
- In the population-based CARDIA study of 4111 young adults, 7 had probable or definite HCM, and 5 others had walls of 15 to 21mm attributed to systemic hypertension.CARDIA study (Maron 1995)
- Age is a red flag for amyloidosis in a patient labeled with HCM, but the Italian authors found no clear age cut-off mandating scintigraphy when other amyloid features are absent.Maurizi 2020
- A negative genetic test does not exclude HCM. One referral laboratory found a causal variant in about 32% of 2912 unrelated probands, with inconclusive results in another 15%.Alfares 2015
- Larger panels add little: a panel of more than 50 genes found only a very small number of additional pathogenic variants beyond an 11-gene panel.Alfares 2015
- Only 8 of 33 genes reported for HCM had definitive evidence in a ClinGen curation, and 31% of 4191 HCM variants in ClinVar sat in genes with limited or no evidence.ClinGen gene curation (Ingles 2019)
- A variant of uncertain significance is not a basis for cascade testing of relatives, ANMCO says; such variants need reassessment over time, and relatives still need clinical follow-up.ANMCO position paper 2025
- Unexplained syncope, presumed to be due to ventricular arrhythmia, carries a particularly poor prognosis and feeds into sudden death risk assessment, so the cause of syncope matters.Mayo Clinic review (Gilreath 2026)
- Guidelines differ on sudden death risk, a 2025 systematic review of guidelines notes. The 2023 ESC guideline starts from the HCM Risk-SCD 5-year estimate, while the 2024 AHA/ACC guideline assesses individual risk factors and treats an apical aneurysm as an independent factor.Guideline systematic review (Sanghvi 2025)
- The 2024 AHA/ACC guideline, published May 8, 2024, drew on a literature search run from September to November 2022, with studies added through May 23, 2023; newer studies cited here postdate it.AHA/ACC HCM guideline 2024
Where to test
- NIH Genetic Testing Registry: hypertrophic cardiomyopathy: NCBI E-utilities listed 80 tests for hypertrophic cardiomyopathy (MedGen concept C0007194) and 73 for primary familial hypertrophic cardiomyopathy (C0949658) on November 13, 2026. NIH does not independently verify submissions or endorse any laboratory.NIH GTR
- Multigene panels through clinical laboratories: ANMCO recommends panels that hold the sarcomere genes MYBPC3, MYH7, TNNT2, TNNI3, TPM1, ACTC1, MYL2 and MYL3 plus genes for mimics, including GLA (Fabry disease), LAMP2 (Danon disease), PRKAG2 and TTR (transthyretin amyloidosis), with counseling before and after the test.ANMCO position paper 2025
- Echocardiography with provocation, and cardiac MRI: The Mayo Clinic review calls provocative maneuvers during echocardiography essential to capture provocable obstruction, and says referral to an HCM center of excellence gives access to advanced imaging.Mayo Clinic review (Gilreath 2026)
- NIH's Genetic Testing Registry listed 400 tests for a search of “Hypertrophic cardiomyopathy” on November 13, 2026. NIH does not endorse or verify the labs it lists.
Family screening and referral
Who else in the family
- As reproduced in a 2025 systematic review of guidelines, the 2024 AHA/ACC guideline says first-degree relatives should be offered both clinical screening (ECG and 2D echocardiogram) and cascade genetic testing when a pathogenic or likely pathogenic variant has been found in the proband (class 1).Guideline systematic review (Sanghvi 2025)
- Children from genotype-positive families and families with early-onset disease: screening at the time a family member is diagnosed, repeated every 1 to 2 years, per the Mayo Clinic review of the guideline schedule.Mayo Clinic review (Gilreath 2026)
- Other children with a family history of HCM: screening by puberty, usually before age 13, repeated every 2 to 3 years.Mayo Clinic review (Gilreath 2026)
- Adults with a family history of HCM: screening at the time a family member is diagnosed, repeated every 3 to 5 years.Mayo Clinic review (Gilreath 2026)
- A relative who tests positive for the family variant continues long-term screening; a relative who tests negative can safely stop, the review says.Mayo Clinic review (Gilreath 2026)
- When the proband has no pathogenic variant, only benign or likely benign variants, the 2024 AHA/ACC guideline says cascade genetic testing of the family is not useful (class 3), as reproduced in the same 2025 systematic review.Guideline systematic review (Sanghvi 2025)
- If genetic testing is not pursued or finds no pathogenic variant in the proband, relatives undergo clinical screening with ECG and echocardiogram, the Mayo Clinic review says.Mayo Clinic review (Gilreath 2026)
- In a 2025 cascade testing study cited by the Mayo Clinic review, 128 of 273 relatives who carried the family variant (47%) were diagnosed with HCM at evaluation; the other 145 were genotype-positive without the phenotype.Mayo Clinic review (Gilreath 2026)
- Penetrance among variant carriers found through family screening has been reported at 45.8% to 57.0%, against about 11% in carriers identified incidentally.Mayo Clinic review (Gilreath 2026)
- In Eastern Denmark, the combined clinical and genetic yield of one screening visit was 26% of 1230 relatives; 43 more (4%) developed HCM over a mean 7 years, and only 2 relatives from gene-elusive families with a baseline wall under 10mm did so.Danish family screening (Silajdzija 2024)
- A diagnosis in a child first-degree relative was made in 8% of 594 families screened at a London center, with 72% of affected children aged 12 or younger at diagnosis.Norrish 2019
- Children from genotype-negative families still had a 5-year cumulative incidence of diagnosis of 4.0%, against 11.1% in genotype-positive families, which the authors say supports screening child relatives whatever the genotype.Norrish 2026
Who to refer to
- The Mayo Clinic review calls referral to an HCM center of excellence a guideline-supported recommendation that gives access to the most knowledgeable care, advanced imaging and septal reduction treatment.Mayo Clinic review (Gilreath 2026)
- Patient groups such as the Hypertrophic Cardiomyopathy Association help patients find an HCM center of excellence, according to the Mayo Clinic review.Mayo Clinic review (Gilreath 2026)
- A 2025 systematic review reports that all 3 guidelines it covers (2024 AHA/ACC, 2023 ESC and 2018 Japanese) recommend that septal reduction therapy be performed by experienced operators at experienced centers within a multidisciplinary team.Guideline systematic review (Sanghvi 2025)
- Genetic counselors are typically the most qualified to discuss the risks and benefits of genetic testing and what results mean, the review says.Mayo Clinic review (Gilreath 2026)
- ANMCO says the clinical diagnosis should be made by experienced cardiologists so that the genetic test is well directed and easier to interpret.ANMCO position paper 2025
- As reproduced in a 2025 systematic review of guidelines, the 2024 AHA/ACC guideline says preconception and prenatal reproductive and genetic counseling should be offered in affected families (class 1).Guideline systematic review (Sanghvi 2025)
- Camzyos (mavacamten) is indicated for adults and pediatric patients weighing 30kg or more with symptomatic obstructive HCM, and is available only through the Camzyos REMS program because of the risk of heart failure.Camzyos label
- Myqorzo (aficamten) is indicated for adults with symptomatic obstructive HCM, requires echocardiogram assessments before and during treatment, and is available only through the Myqorzo REMS program.Myqorzo label
Find a specialist by state
From the CMS NPI Registry, a public directory of US clinicians by registered specialty. A listing is not an endorsement and says nothing about experience with Hypertrophic cardiomyopathy; patient organizations and academic centers can often name experienced clinicians.
ICD-10-CM codes for Hypertrophic cardiomyopathy
For orders, referrals and prior authorization. Each code is checked daily against NLM's ICD-10-CM service.
Once the diagnosis is confirmed
For the patient: why your doctor ordered this test
Plain language a patient can read or take home.
Your doctor ordered these tests because of a heart murmur, an unusual heart tracing, or a symptom such as chest pain, shortness of breath, a racing heartbeat or fainting. Tests are also ordered when a close relative has hypertrophic cardiomyopathy.
Hypertrophic cardiomyopathy means the heart muscle is thicker than it should be without another cause such as high blood pressure. It often runs in families. Many people with it have few or no symptoms and live a normal life span. It can cause heart rhythm problems and, in some people, it blocks blood flow out of the heart.
The main test is an ultrasound of the heart (echocardiogram). You may be asked to bear down, stand up or exercise during the scan, because the blockage can come and go. Your doctors or health care professionals may also order a heart tracing (ECG), a heart MRI and a genetic test. They will ask about heart problems or sudden deaths in your family.
Other conditions can also thicken the heart muscle, including athletic training, high blood pressure and some rare diseases, so part of the testing is to tell these apart. If you are diagnosed, your parents, brothers, sisters and children are usually offered heart checks, and sometimes a genetic test.
Questions clinicians ask about Hypertrophic cardiomyopathy testing
Which combinations of findings should prompt testing for hypertrophic cardiomyopathy?
In published screening and biopsy studies, the highest yields came from relative who carries the family's pathogenic variant plus ECG and echocardiogram at cascade testing (47% of 273 relatives found to carry the family variant in a 2025 cascade testing study cited by a Mayo Clinic review), and from first-degree or other relative of a patient with HCM plus ECG, echocardiogram and genetic testing at one screening visit (26% of 1230 relatives from 531 families screened at inherited cardiomyopathy clinics in Eastern Denmark, 2006 to 2023). Among patients already diagnosed, the most common combination began with unexplained wall thickening, seen in 70.2% to 82.6% of 682 patients with HCM by ESC criteria at an Istanbul center, and a Mayo Clinic series of 135 patients with a normal ECG and 2350 with an abnormal ECG. These figures describe study groups, not any one patient's chance of having hypertrophic cardiomyopathy.
What wall thickness defines hypertrophic cardiomyopathy in adults and in relatives?
A maximal end-diastolic wall thickness of 15mm or more anywhere in the left ventricle, with no other cause of hypertrophy, is the adult criterion in the 2024 AHA/ACC guideline. More limited hypertrophy of 13 to 14mm can be diagnostic in family members of a patient with HCM or together with a pathogenic or likely pathogenic variant. The 2023 ESC guideline uses 15mm in any segment and 13mm or more in adult first-degree relatives of patients with unequivocal disease. In children the Mayo Clinic review gives z-score criteria: at least 2 standard deviations above the mean with a positive family history or genetic test, or 2.5 without (Sanghvi 2025; Gilreath 2026).
What LVOT gradient defines obstructive HCM, and how is it provoked?
A left ventricular outflow tract gradient of at least 30mmHg defines obstruction, and at least 50mmHg is generally considered the level needed to cause symptoms (Gilreath 2026). The 2024 AHA/ACC guideline recommends an echocardiogram with provocative maneuvers when the resting peak gradient is under 50mmHg, and exercise echocardiography in symptomatic patients with no resting or provocable gradient of 50mmHg or more, as reproduced in a 2025 systematic review of guidelines (Sanghvi 2025). Maneuvers named by the Mayo Clinic review are Valsalva, squat-to-stand, amyl nitrite and exercise. In 320 consecutive patients, 70% had obstruction at rest or with exercise, and Valsalva underestimated exercise-induced obstruction (Maron 2006).
How often is genetic testing positive in HCM, and which genes are tested?
A pathogenic or likely pathogenic variant is found in 30% to 40% of patients with HCM (Gilreath 2026), and one referral laboratory reported about 32% among 2912 unrelated probands with another 15% inconclusive (Alfares 2015). Over 90% of pathogenic variants are in sarcomere genes, with MYBPC3 and MYH7 the most common. A ClinGen curation rated 8 genes as definitive: MYBPC3, MYH7, TNNT2, TNNI3, TPM1, ACTC1, MYL2 and MYL3 (Ingles 2019). Panels often add genes for mimics such as GLA, LAMP2, PRKAG2 and TTR. Genetic testing is not required for the diagnosis.
How often should first-degree relatives of a patient with HCM be screened?
Every 1 to 2 years for children from genotype-positive families or families with early-onset disease, every 2 to 3 years for other children, and every 3 to 5 years for adults is the schedule the Mayo Clinic review reports as consistent with the 2024 AHA/ACC guideline. Screening starts when the family member is diagnosed, or by puberty for children in the lower-risk group. Screening uses an ECG and echocardiogram, plus cascade genetic testing when the proband carries a pathogenic or likely pathogenic variant. Relatives who test negative for the family variant can stop screening (Gilreath 2026; Sanghvi 2025).
How does the 2024 AHA/ACC guideline assess sudden cardiac death risk in HCM?
Every 1 to 2 years after an assessment at the first evaluation is the interval the guideline recommends for a systematic noninvasive review of risk. The factors it lists are a personal history of cardiac arrest or sustained ventricular arrhythmia, syncope suspected to be arrhythmic, premature HCM-related sudden death, cardiac arrest or sustained ventricular arrhythmia in a close relative, maximal wall thickness, ejection fraction, apical aneurysm, and nonsustained ventricular tachycardia on ambulatory monitoring. It names massive hypertrophy of 30mm or more, an ejection fraction under 50% and an apical aneurysm with transmural scar among its major risk factors. The 2023 ESC guideline instead starts from the HCM Risk-SCD 5-year estimate (Sanghvi 2025).
How often does a patient labeled with HCM turn out to have amyloidosis, Fabry disease or Danon disease?
About 9% of 343 patients aged 40 or older referred to Italian centers with an initial HCM diagnosis had cardiac amyloidosis, rising to 26% at age 80 or older (Maurizi 2020). A meta-analysis pooled a Fabry disease prevalence of 1.2% across 10,080 patients with left ventricular hypertrophy or HCM who were screened for it (Monda 2023). LAMP2 mutations causing Danon disease were found in 1% of 197 French index cases (Charron 2004). As reproduced in a 2025 systematic review, the 2024 AHA/ACC guideline calls cardiac MRI useful and recommends genetic testing for other causes of hypertrophy when another diagnosis is suspected (Sanghvi 2025).
How is HCM told apart from athlete's heart?
A left ventricular cavity under 54mm separated HCM from athlete's heart with 100% sensitivity and specificity in a study of 28 athletes and 25 untrained patients with HCM matched for wall thickness of 13 to 15mm (Caselli 2014). Among 947 elite athletes, only 1.7% had a wall of 13mm or more, the thickest wall was 16mm, and all of those with 13mm or more had enlarged cavities (Pelliccia 1991). The Mayo Clinic review adds systolic anterior motion, diastolic dysfunction, outflow obstruction and late gadolinium enhancement away from the right ventricular insertion points as features favoring HCM. The 2024 AHA/ACC guideline calls cardiac MRI useful when athlete's heart is suspected, as reproduced in a 2025 systematic review (Sanghvi 2025).
What is the ICD-10 code for hypertrophic cardiomyopathy?
The ICD-10-CM codes are I42.1, Obstructive hypertrophic cardiomyopathy, and I42.2, Other hypertrophic cardiomyopathy, per the National Library of Medicine's ICD-10-CM lookup checked November 13, 2026. Family history of sudden cardiac death is coded separately as Z82.41.
Sources
- 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. Circulation 2024;149(23):e1239-e1311 (Ommen SR, Ho CY, Asif IM et al), via PubMed abstract; full text not opened, so its recommendations are cited here through Sanghvi 2025 and Gilreath 2026, 2024-05-08.
- Hypertrophic cardiomyopathy management: a systematic review of the clinical practice guidelines and recommendations. European Heart Journal. Quality of Care & Clinical Outcomes 2025;11(7):919-933 (Sanghvi MM, Dhall E et al; reproduces the 2024 AHA/ACC, 2023 ESC and 2018 JCS/JHFS recommendations; no conflict of interest declared), via PubMed Central, 2025-01-02.
- Pathogenesis, screening, and diagnosis of hypertrophic cardiomyopathy. BMJ Medicine 2026;5(1):e002433 (Gilreath KM, Newman DB, Ommen SR, Geske JB; the authors declare no interests), via PubMed Central, 2026-10-01.
- ANMCO position paper 'Hypertrophic cardiomyopathy: from diagnosis to treatment'. European Heart Journal Supplements 2025;27(Suppl 5):v256-v279 (Chimenti C, Iacovoni A, Montalto A et al; Italian Association of Hospital Cardiologists; no conflict of interest declared), via PubMed Central, 2025-05-15.
- Frequency and clinicoeconomic impact of delays to definitive diagnosis of obstructive hypertrophic cardiomyopathy in the United States. Journal of Medical Economics 2023;26(1):682-690 (Naidu SS, Sutton MB, Gao W et al; 2 authors employed by MyoKardia, a wholly owned subsidiary of Bristol Myers Squibb), via PubMed abstract, 2023.
- Prevalence of hypertrophic cardiomyopathy in a general population of young adults. Echocardiographic analysis of 4111 subjects in the CARDIA Study. Coronary Artery Risk Development in (Young) Adults. Circulation 1995;92(4):785-9 (Maron BJ, Gardin JM, Flack JM et al), via PubMed abstract, 1995-08-15.
- Hypertrophic cardiomyopathy is predominantly a disease of left ventricular outflow tract obstruction. Circulation 2006;114(21):2232-9 (Maron MS, Olivotto I, Zenovich AG et al), via PubMed abstract, 2006-11-06.
- Outcome of patients with hypertrophic cardiomyopathy and a normal electrocardiogram. Journal of the American College of Cardiology 2009;54(3):229-33 (McLeod CJ, Ackerman MJ, Nishimura RA et al), via PubMed abstract, 2009-07-14.
- Prevalence and characteristics of normal electrocardiograms in hypertrophic cardiomyopathy. Journal of Electrocardiology 2026;96:154363 (Guler A, Gorgulu BK, Surgit O et al; the authors declare no conflict of interest), via PubMed abstract, 2026-05-16.
- Detection of apical hypertrophic cardiomyopathy by cardiovascular magnetic resonance in patients with non-diagnostic echocardiography. Heart 2004;90(6):645-9 (Moon JC, Fisher NG, McKenna WJ, Pennell DJ), via PubMed abstract, 2004-06.
- Genotype and Lifetime Burden of Disease in Hypertrophic Cardiomyopathy: Insights from the Sarcomeric Human Cardiomyopathy Registry (SHaRe). Circulation 2018;138(14):1387-1398 (Ho CY, Day SM, Ashley EA et al; SHaRe is funded by an unrestricted research grant from MyoKardia, Inc, 2 authors were MyoKardia employees and 5 received MyoKardia research support), via PubMed abstract; funding statement read in PubMed Central, 2018-08-23.
- Gender-related differences in the clinical presentation and outcome of hypertrophic cardiomyopathy. Journal of the American College of Cardiology 2005;46(3):480-7 (Olivotto I, Maron MS, Adabag AS et al), via PubMed abstract, 2005-08-02.
- Associations Between Female Sex, Sarcomere Variants, and Clinical Outcomes in Hypertrophic Cardiomyopathy. Circulation. Genomic and Precision Medicine 2021;14(1):e003062 (Lakdawala NK, Olivotto I, Day SM et al), via PubMed abstract, 2020-12-07.
- The upper limit of physiologic cardiac hypertrophy in highly trained elite athletes. The New England Journal of Medicine 1991;324(5):295-301 (Pelliccia A, Maron BJ, Spataro A et al), via PubMed abstract, 1991-01-31.
- Differentiating left ventricular hypertrophy in athletes from that in patients with hypertrophic cardiomyopathy. The American Journal of Cardiology 2014;114(9):1383-9 (Caselli S, Maron MS, Urbano-Moral JA et al), via PubMed abstract, 2014-08-12.
- Hypertrophic cardiomyopathy: prevalence of disease-specific red flags. European Heart Journal 2025;46(31):3082-3094 (Maurizi N, Monda E, Biagini E et al), via PubMed abstract, 2025-08-14.
- Prevalence of cardiac amyloidosis among adult patients referred to tertiary centres with an initial diagnosis of hypertrophic cardiomyopathy. International Journal of Cardiology 2020;300:191-195 (Maurizi N, Rella V, Fumagalli C et al), via PubMed abstract, 2019-07-17.
- Impact of GLA Variant Classification on the Estimated Prevalence of Fabry Disease: A Systematic Review and Meta-Analysis of Screening Studies. Circulation. Genomic and Precision Medicine 2023;16(6):e004252 (Monda E, Diana G, Graziani F et al; disclosures: none), via PubMed abstract, 2023-12-04.
- Danon's disease as a cause of hypertrophic cardiomyopathy: a systematic survey. Heart 2004;90(8):842-6 (Charron P, Villard E, Sébillon P et al), via PubMed abstract, 2004-08.
- Concomitant Hypertension in Hypertrophic Cardiomyopathy: Clinical Phenotype and Prognostic Associations of Cardiovascular Magnetic Resonance Biomarkers. European Journal of Preventive Cardiology 2026, online ahead of print, zwag343 (Florence J, Gonçalves T, Toupin S et al), via PubMed abstract, 2026-07-13.
- Results of clinical genetic testing of 2,912 probands with hypertrophic cardiomyopathy: expanded panels offer limited additional sensitivity. Genetics in Medicine 2015;17(11):880-8 (Alfares AA, Kelly MA, McDermott G et al), via PubMed abstract, 2015-01-22.
- Evaluating the Clinical Validity of Hypertrophic Cardiomyopathy Genes. Circulation. Genomic and Precision Medicine 2019;12(2):e002460 (Ingles J, Goldstein J, Thaxton C et al), via PubMed abstract, 2019-02.
- Family Screening in Hypertrophic Cardiomyopathy: Identification of Relatives With Low Yield From Systematic Follow-Up. Journal of the American College of Cardiology 2024;84(19):1854-1865 (Silajdzija E, Vissing CR, Christensen EB et al; supported by Rigshospitalet Research Council; the authors report no relevant relationships), via PubMed abstract, 2024-10-02.
- Yield of Clinical Screening for Hypertrophic Cardiomyopathy in Child First-Degree Relatives. Circulation 2019;140(3):184-192 (Norrish G, Jager J, Field E et al), via PubMed abstract, 2019-04-22.
- The Yield of Clinical Screening in Pediatric Relatives of Hypertrophic Cardiomyopathy With Negative Genetic Testing. JACC. Heart Failure 2026;14(10):103283 (Norrish G, Pascall E, Field E et al; charity and UK research council funding), via PubMed abstract, 2026-08-10.
- Camzyos (mavacamten) [Myokardia, Inc.] (prescribing information, SPL version 9, NDA214998). Myokardia, Inc., via openFDA, 2026-09-30.
- Myqorzo (aficamten) [Cytokinetics Inc.] (prescribing information, SPL version 2, NDA219083). Cytokinetics Inc., via openFDA, 2025-12-16.
- NIH Genetic Testing Registry tests for hypertrophic cardiomyopathy, MedGen concept C0007194 (80 tests listed in NCBI E-utilities on November 13, 2026). National Center for Biotechnology Information, NIH, 2026-11-13.
- ICD-10-CM search results for "I42.1" (Clinical Table Search Service). National Library of Medicine, 2026-11-13.
A reference for licensed professionals, checked against its sources on November 13, 2026. It summarizes what the cited guidance says and does not tell anyone how to diagnose or treat a specific patient. Guidelines change; the current guideline and the treating clinician's judgment govern. Trial Friend is an independent information service, not a medical provider.