Hypertrophic Cardiomyopathy

Question 1

Explain the underlying process in cardiomyopathy

Answer 1

Walls of the heart become thick, heavy and hypercontractile. This reduces the chamber volume leading to reduced diastolic filling and so a reduced cardiac output.

Walls also become stiff and less compliant

Question 2

What type of heart failure is caused by hypertrophic cardiomyopathy?

Answer 2

Diastolic heart failure

Question 3

What type of murmur is heard with hypertrophic cardiomyopathy?

Answer 3

Crescendo-decrescendo- due to reduced area for outflow which occurs due to the venturi effect as the anterior leaflet of the mitral valve is drawn towards to septum§

Question 4

What may be heard on auscultation for hypertrophic cardiomyopathy?

Answer 4

S4- A fourth heart sound

Question 5

What is the mode of inheritance of HOCM?

Answer 5

50% are genetically inherited and this is autosomal domoniant

Question 6

What is the leading cause of sudden cardiac death in the young?

Answer 6

HOCM

Question 7

What genes are affected in the genetically inherited form?

Answer 7

Beta myosin
Alpha tropomyosin
Troponin T

Question 8

Why is it important to ask about family history in HOCM?

Answer 8

50% are inherited in an autosomal dominant manner so ask about history of sudden cardiac death

Question 9

What are some of the symptoms of HOCM?

Answer 9

Angina- blood supply does not adequately match the demands of the hypertrophied myocardium
Syncope
VF (Treatable with defibs)
Dyspnoea
Palpitations

Question 10

What medication is contraindicated in HOCM?

Answer 10

Digoxin- it increases the force of contraction which can then further the obstruction due to the venturi effect

Question 11

What may be used to treat HOCM?

Answer 11

Beta blockers- slow the heart rate
Verapamil/Diltiazem
Surgery
Implantable defibrillators