Hypertrophic obstructive cardiomyopathy

Question 1

What is HOCM?

Answer 1

Hypertrophy (thickening) of the left ventricle muscle, particularly affecting the ventricular septum which reduces space inside the ventricle and blocks blood flow up to the aorta which is called left ventricular outflow tract obstruction

Question 2

What is HOCM associated with?

Answer 2

Heart failure, MI, arrhythmia and sudden cardiac death.

Arrhythmia and sudden death often occur during exertion.

Question 3

What causes HOCM?

Answer 3

Autosomal dominant genetic condition resulting from a defect in the genes for sarcomere proteins.

FH of heart disease is relevant.

Question 4

Presentation of HOCM?

Answer 4

• Most pt’s are asymptomatic
• SOB
• fatigue
• dizziness
• syncope
• chest pain
• palpitations

Question 5

Examination findings in HOCM?

Answer 5

• Ejection systolic murmur at the lower left sternal border (louder with Valsalva manoeuvre and decreases with squatting)
• Fourth heart sound
• Thrill at lower L sternal border

Question 6

Diagnosis of HOCM?

Answer 6

Echocardiogram or cardiac MRI, and genetic testing.

Question 7

Management of HOCM?

Answer 7

• Beta blockers
• Surgical myectomy (removing part of the heart septum to relieve the obstruction)
• Implantable cardioverter defibrillator (for those at risk of sudden cardiac death or ventricular arrhythmias)
• Heart transplant

Question 8

What advice is given to patients with HOCM?

Answer 8

Avoid intense exercise, heavy lifting & dehydration.

ACE inhibitors & nitrates are avoided as they can worsen LVOT obstruction.

Question 9

Complications of HOCM?

Answer 9

Arrhythmia, mitral regurgitation, heart failure, and sudden cardiac death.