HOCM

Question 1

Hypertrophic (obstructive) cardiomyopathy presentation

Answer 1

This young man has complained of palpitations whilst playing football. Examine his cardiovascular system.

Question 2

Clinical signs of Hypertrophic (obstructive) cardiomyopathy

Answer 2

1. Jerky pulse character
2. Double apical impulse (palpable atrial and ventricular contraction)
3. Thrill at the lower left sternal edge
4. Auscultation:
   - Ejection systolic murmur (ESM) at the lower left sternal edge that radiates throughout the precordium.
   - A fourth heartsound (S4) is present due to blood hitting a hypertrophied stiff LV during atrial systole.
   - Dynamic ESM accentuated by reducing LV volume, e.g. standing from squatting or during a strain phase of Valsalva.
5. There may be associated mitral valve prolapse (MVP)
6. There may be features of Friedreich’s ataxia or myotonic dystrophy

Question 3

Auscultation in HOCM

Answer 3

1. Ejection systolic murmur (ESM) at the lower left sternal edge that radiates throughout the precordium.
2. A fourth heartsound (S4) is present due to blood hitting a hypertrophied stiff LV during atrial systole.
3. Dynamic ESM accentuated by reducing LV volume, e.g. standing from squatting or during a strain phase of Valsalva.
4. There may be associated mitral valve prolapse (MVP)

Question 4

Investigation for HOCM

Answer 4

1. ECG: LVH with strain (deep T‐wave inversion across precordial leads)
2. CXR: often normal
3. TTE:
   - Asymmetrical septal hypertrophy
   - Systolic ant. motion of the ant. mitral leaflet across the LVOT due to misalignment of septal papillary muscle,
   - LVOT gradient (rest/exercise or dobutamine stress)
4. Cardiac MR: identifies apical HCM more reliably than TTE
5. Cardiac catheterization:
   - gradient accentuated by a ventricular ectopic or pharmacological stress,
   - identification of septals
6. Genetic tests: sarcomeric proteins mutation

LVOT = left ventricular outflow tract, ant. = anterior

Question 5

Management of HOCM

Answer 5

1. Asymptomatic: Avoidance of strenuous exercise, dehydration and vasodilators
2. Symptomatic and LVOT gradient >30 mm Hg
- β‐Blockers
- Pacemaker
- Alcohol septal ablation
- Surgical myomectomy
3. Rhythm disturbance/high‐risk SCD:
- ICD
4. Refractory:
- Cardiac transplant
* Genetic counselling of first‐degree relatives (autosomal dominant inheritance)

Question 6

Prognosis of HOCM

Answer 6

i. Annual mortality rate in adults is 2.5%
ii. Poor prognosis factors:
1. Young age at diagnosis
2. Syncope
3. Family history of sudden death
4. Septal thickness > 3 cm