QuestionSBA
QuestionChoice
The vignette suggests a diagnosis of hypertrophic cardiomyopathy and chest X-ray does not play any role in its diagnosis.
10037215
d
Chest X-ray
QuestionChoice
Myocardial scintigraphy is used to diagnose coronary artery disease (CAD). The purpose of myocardial scintigraphy is to detect myocardial ischaemia. It does not play any role in diagnosing HOCM.
10037216
e
Myocardial Scintography
QuestionChoice
Holter monitoring is an important investigation that is warranted when arrhythmia is suspected but it cannot confirm the diagnosis of HOCM.
10037213
b
Holter monitoring
QuestionChoice
ECG would be the first line of investigation in the aforementioned scenario and even though there are ECG changes associated with HOCM such as septal Q waves (deep narrow dagger-like Q waves seen in lateral and inferior leads), it cannot confirm the given diagnosis and further investigation is imperative.
10037214
c
ECG
QuestionChoice
Cardiac MRI helps in the diagnosis of hypertrophic cardiomyopathy (HOCM) by identifying areas of hypertrophy, which are often not well visualised by echocardiography, providing more accurate wall thickness measurements and differentiating HOCM from other causes of left ventricular hypertrophy.
10037212
a
Cardiac MRI
QuestionComment
how can we rule out wolff parkinson white from the question stem?
54066
QuestionComment
WPW is usually not inherited, family history is more relevant for HOCM
57143
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Mirror syndrome 
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eosinophilic patience
QuestionComment
The fact that they put MRI there instead of echo really made me second guess myself... 
60136
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Odor Bladder
QuestionComment
In clinical practice, you would do an echocardiogram 
60974
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Neutrophillia
QuestionComment
Why not ARVC or brugada syndrome, is it that HOCM is the most common and therefor more likely? 
61665
QuestionComment
and the positive family history
61784
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Nightshift Bradykinin
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j.g.73
Concept
Chapter
# Summary

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant condition characterised by left ventricular hypertrophy without an apparent cause. It is a common inherited cardiac condition and a significant cause of sudden cardiac death in young adults. HCM is attributed to mutations in genes encoding sarcomere proteins leading to chaotic and disorganized myocytes. HCM may be asymptomatic but can also lead to exertional syncope, dyspnoea, chest pain and heart failure. Definitive diagnosis is made via echocardiogram. Management involves lifestyle modifications, medication for symptom control, surgical or interventional procedures for severe cases, and consideration of implantable cardioverter-defibrillators in those at risk of sudden cardiac death. Prognosis varies, with an annual mortality rate of 1.1%, and a 20-year survival rate estimated at 81% after diagnosis.

# Definition 

Hypetrophic cardiomyopathy (HCM) is an autosomal dominant condition characterised by asymmetrical septal hypertrophy leading to left ventricular hypetrophy and diastolic dysfunction in the absence of an obvious cause (e.g. hypertension). 

# Epidemiology 

HCM is estimated to impact 1 in 500 people. It is the most common inherited cardiac condition. Inheritance of HCM is in an autosomal dominant fashion. However, 50% of cases result due to sporadic mutations. Most of the hypertrophy develops during childhood and adolescent, however, genetic variation means late-onset disease can occur.

# Pathophysiology

HCM is attributed to mutations in one or a number of genes that encode for sarcomere proteins. A common mutation is in the beta-myosin heavy chain gene leading to myocyte hypetrophy with chaotic and disorganised myocytes.  

# Symptoms

* May be asymptomatic 
* Or can present with symptoms of left ventricular outflow obstruction, pulmonary congestion or heart failure: 
	* Exertional syncope 
	* Pre-syncope/syncope
	* Sudden cardiac death 
	* Exertional dyspnoea 
	* Fatigue
	* Chest pain: may be anginal (due to decreased blood flow through the coronary arteries) or atypical. 

# Signs

Physical examination can often be normal or non-specific, however typical findings may include:

* "Jerky" pulse
* Double apex beat
* Harsh ejection systolic murmur
* Apical thrill
* A wave in JVP 

# Differential Diagnoses

* Aortic Stenosis 
	* Similarities: both may have an ejection systolic murmur and present similarly with chest pain, exertional syncope and dyspnoea. 
	* Differences: can be difficult to delineate clinically, but demographics may be very different. Aortic stenosis tends to affect older patients, whilst HOCM is likely to be found in younger patients. 

* Hypertensive Disease 
	* Similarities: chronic high blood pressure can lead to left ventricular hypertrophy. 
	* Differences: echocardiogram reveals asymmetrical left ventricular hypertrophy in HOCM. Family history and patient demographics may also suggest HOCM over hypertensive disease. 

* Supravalvular Aortic Stenosis: 
	* Similarities: both may have an ejection systolic murmur. 
	* Differences: supravalvular aortic stenosis is a congenital cardiac condition whereas HOCM tends to develop over time. Supravalvular  stenosis can be distinguished from HOCM on echocardiography due to the level of obstruction either above or below the aortic valve respectively. 

# Investigations

**ECG** typically demonstrates: 

* Abnormal Q waves
* Deep T wave inversion 
* LVH 

**Echocardiogram: definitive diagnosis** 

* HCM is reliably diagnosed on echocardiogram. 
* Findings of HOCM on echocardiogram can be remembered with the mnemonic 'MR SAM ASH'. 
	* **M**itral **R**egurgitation
	* **S**ystolic **A**nterior **M**otion of the mitral valve leaflets 
	* **A**symmetrical **S**eptal **H**ypertrophy. 

**Genetic testing:** there is a role for genetic testing in HCM in families where there are known cases of HCM. 

# Management

## Conservative 

Many patients with HCM do not have any symptoms and have a normal life expectancy. They are often counselled on not undertaking particularly stressful exercise or competitive athletics.  

## Medical 

Medical treatment of HCM remains symptoms control. 
**1st line: beta-blockers** to reduce palpitations symptoms, ectopic beats and are anti-anginal. 

Other medications that can be used are: non-dihydropyridine calcium channel blockers (verapamil), anti-arrhythmics (amiodarone) and anticoagulation (for AF). 

## Surgical and Interventional

Management of the septal hypetrophy in those with severe left ventricular outflow tract obstruction (LVOTO) or symptoms that are refractory to medical management. 

* Surgical septal myectomy
* Alcohol septal ablation

For those at significant risk of sudden cardiac death an ICD may be inserted to mitigate this risk. 

# Complications

The abnormal morphology of the left ventricle can cause severe consequences for heart function: 

* Left ventricular outflow tract obstruction (LVOTO)
* Diastolic dysfunction: HFpEF
* Ischaemia 
* Mitral regurgitation: MR SAM ASH on echocardiogram 

# Prognosis 

The annual mortality rate for HCM is 1.1% of people per year and the HCM survival rate is estimated to be 81% at 20 years after diagnosis. 

# NICE Guidelines

[NICE Guidelines on Non-Surgical Reduction of the Myocardium in HCM](<https://www.nice.org.uk/guidance/ipg40>)

# References

[Patient UK HCM Summary](<https://patient.info/doctor/hypertrophic-cardiomyopathy-pro>)

[American Heart Association Article on HCM](<https://www.ahajournals.org/doi/full/10.1161/circresaha.116.309348>)
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Hypertrophic cardiomyopathy
Topic
35
Cardiology
Condition
126
Cardiac arrest
UkmlaTopic
4
Cardiovascular
19846
Cardiac MRI is essential for diagnosing hypertrophic cardiomyopathy by accurately assessing wall thickness and identifying hypertrophy not visible on echocardiography.
Presentation
83
Blackouts and faints
UkmlaTopic
4
Cardiovascular
A 25-year-old female presents to the emergency department after collapsing during a football game. She is currently haemodynamically stable. Her father passed away at the age of 42 after a collapse.

Which of the following investigations would confirm the diagnosis?
a