Myocardial Disease - Hypertrophic Obstructive Cardiomyopathy

Question 1

What is Hypertrophic Obstructive Cardiomyopathy?

Answer 1

Autosomal Dominant disorder of muscle tissue caused by defects in genes encoding contractile proteins.

Question 2

Associations of Hypertrophic Obstructive Cardiomyopathy.

Answer 2

1. Friedrich’s Ataxia.

2. Wolff-Parkinson White.

Question 3

Pathophysiology of Hypertrophic Obstructive Cardiomyopathy.

Answer 3

1. Commonest Defect : Mutation in Gene encoding B-Myosin Heavy Chain Protein or Myosin-Binding Protein C.
2. Predominantly Diastolic Dysfunction (LV Hypertrophy - Decreased Compliance - Decreased CO).
3. Myofibrillar Hypertrophy with Chaotic and Disorganised Fashion Myocytes (‘Disarray’) and Fibrosis on Biopsy.

Question 4

Clinical Features of Hypertrophic Obstructive Cardiomyopathy.

Answer 4

1. Asymptomatic.
2. Exertional Dyspnoea.
3. Angina.
4. Syncope following Exercise (Subaortic Hypertrophy of Ventricular Septum - Functional Aortic Stenosis).
5. Sudden Death (Ventricular Arrhythmias).
6. Jerky Pulse, Large A Waves, Double Apex Beat.

Question 5

Describe the murmur in Hypertrophic Obstructive Cardiomyopathy

Answer 5

1. Ejection Systolic Murmur.
2. Increases with Valsalva Manoeuvre.
3. Decreases with Squatting.
4. Impaired Mitral Valve Closure - can cause regurgitation.

Question 6

ECG Findings in Hypertrophic Obstructive Cardiomyopathy.

Answer 6

1. LV Hypertrophy.
2. Non-Specific ST and T Wave Abnormalities - Progressive T Wave Inversion.
3. Deep Q Waves.

Question 7

ECHO Findings in Hypertrophic Obstructive Cardiomyopathy.

Answer 7

MR. SAM ASH :

1. Mitral Regurgitation (MR).
2. Systolic Anterior Motion of Anterior Mitral Valve Leaflet (SAM).
3. Asymmetric Hypertrophy (ASH).

Question 8

Management of Hypertrophic Obstructive Cardiomyopathy (5).

Answer 8

ABCDE :

1. A - Amiodarone.
2. B - B-Blockers/Verapmil.
3. C - Cardioverter Defibrillator.
4. D - Dual Chamber Pacemaker.
5. E - Endocarditis Prophylaxis.

Question 9

What 3 drugs must be avoided in Hypertrophic Obstructive Cardiomyopathy?

Answer 9

1. Nitrates.
2. ACE Inhibitors.
3. Inotropes.

Question 10

Prognosis of Hypertrophic Obstructive Cardiomyopathy.

Answer 10

Sudden Death - Ventricular Arrhythmia (VT due to Ischaemia).