Hypertrophic Obstructive Cardiomyopathy Flashcards
What is hypertrophic obstructive cardiomyopathy (HOCM)?
It is defined as a genetic condition in which there is an asymmetrical increase in left ventricular wall thickness – usually affecting the septum
Does hypertrophic obstructive cardiomyopathy lead to predominately systolic or diastolic dysfunction?
Diastolic
What is the inheritance of hypertrophic obstructive cardiomyopathy?
Autosomal dominant
Which genetic mutation is associated with hypertrophic obstructive cardiomyopathy?
Cardiac sarcomere proteins encoding genes
Name three cardiac sarcomere proteins
Beta-myosin heavy chain
Myosin-binding protein C
Cardiac troponin C
What is the function of cardiac sacromere proteins?
They are important structural components of cardiac muscle
Due to the genetic mutation of the cardiac sarcomere protein genes, describe the pathophysiology of hypertrophic obstructive cardiomyopathy?
This results in diastolic dysfunction, which in turn leads to decreased cardiac output and thus left ventricular hypertrophy
What are the two associations of hypertrophic obstructive cardiomyopathy?
Friedrich’s Ataxia
Wolff-Parkinson White Syndrome
What are the eleven clinical features associated with hypertrophic obstructive cardiomyopathy?
Exertional Dyspnoea
Exertional Syncope
Palpitations
Chest Pain
Jerky Pulse Rate
Double Apex Beat
Systolic Murmurs
S4 Sound
Split S2 Sound
Prominent A Wave of JVP
Sudden Cardiac Death
What two heart murmurs are associated with hypertrophic obstructive cardiomyopathy?
Ejection Systolic
Mitral Regurgitation
Which heart murmur is most commonly associated with hypertrophic obstructive cardiomyopathy?
Ejection Systolic
Describe three features of the ejection systolic murmur associated with hypertrophic obstructive cardiomyopathy
It is loudest between the apex and left sternal border
It is worsened upon the Valsalva manoeuvre and expiration
It improves upon squatting
What does the development of the ejection systolic murmur in hypertrophic obstructive cardiomyopathy indicate?
Left ventricular outflow obstruction
How is sudden cardiac death a clinical feature of hypertrophic obstructive cardiomyopathy?
It can result in the development of ventricular arrhythmias
What are the five murmur features of mitral regurgitation?
Holosystolic, High Pitched, Whistling Murmur
Murmur Radiation To Axilla
Quiet, Soft S1
S3 Sound
Widely Split S2
What is the most common cause of sudden cardiac death in young athletic males? How?
Hypertrophic obstructive cardiomyopathy
It can lead to the development of ventricular arrhythmias
What three investigations are used to diagnose hypertrophic obstructive cardiomyopathy?
ECG Scan
ECHO Scan
Cardiac MRI Scan
What are the five features of hypertrophic obstructive cardiomyopathy on ECG scans?
Non-Specific ST Segment Abnormalities
Non-Specific T Wave Abnormalities
Progressive T Wave Inversion
Deep, Narrow Q Waves
Atrial Fibrillation Features
What is the first line investigation used to diagnose hypertrophic obstructive cardiomyopathy?
ECHO scans
What are the three features of hypertrophic obstructive cardiomyopathy on ECHO scans?
Asymmetrical Left Ventricular Wall Thickness > 15mm During Diastole
Mitral Regurgitation Features
Systolic Anterior Motion of the Anterior Mitral Valve Leaflet
How can we remember the features of hypertrophic obstructive cardiomyopathy on ECHO scans?
MR SAM ASH
Mitral Regurgitation
Systolic Anterior Motion
ASymetric Hypertrophy
Which ECHO scans are preferred to diagnose hypertrophic obstructive cardiomyopathy - transoesophageal or transthoracic?
Transthoracic
How are cardiac MRI scans used to investigate hypertrophic obstructive cardiomyopathy?
They are not required for a diagnosis, however if local resources permit should be considered as part of the assessment
What is the histological feature of hypertrophic obstructive cardiomyopathy?
Myofibrillar hypertrophy with chaotic and disorganised fashion myocytes and fibrosis
