Examine this patient's cardiovascular system.



· Patients may be asymptomatic.

· Severe cardiac failure (in infants).

· Premature unexpected death: may be presenting symptom in children or young

· Dyspnoea on exertion: (in -50% of patients).

· Chest pain (in -50%; may be exertional or occur at rest).

· Syncope (in 15-25%).

· Dizziness and palpitations.

· Obtain a family history of the following: (a) similar cardiomyopathy, (b) sudden


· Carotid pulse is bifid.

· 'a' wave in the JVP.

· Double apical impulse (left ventricular heave with a prominent presystolic pulse caused by atrial


· Pansystolic murmur at the apex due to mitral regurgitation.

· Ejection systolic murmur along the left sternal border (across the outflow tract obstruction);

accentuated by standing and Valsalva manoeuvre and softer on squatting (squatting increases LV

cavity size and reduces outflow tract obstruction).

· Fourth heart sound.


This patient has hypertrophic cardiomyopathy (aetiology) as evidenced by a double apical impulse and

ejection systolic murmur along the left sternal border which is heard better on standing (lesion); the

patient is in cardiac failure.


How would you investigate this patient?

· Echocardiogram is useful for assessing left ventricular structure and function, gradients, valvular

regurgitation, and atrial dimensions. Characteristic findings include systolic anterior motion of mitral valve

(SAM), asymmetric hypertrophy (ASH) and mitral regurgitation.

· ECG may be normal (in about 5% of patients) or show abnormalities including left ventricular

hypertrophy, atrial fibrillation, left axis deviation, right bundle branch block and myocardial disarray

(e.g. ST-T wave changes, intraventricular conduction defects, abnormal Q waves); bizarre or

abnormal findings in young patients should raise suspicion of hypertrophic cardiomyopathy,

especially if family members are also affected.

· Chest radiograph may be normal or show evidence of left or right atrial or left ventricular enlargement.

· Treadmill exercise test is performed when patients have angina (ST segment changes of >2 mm

documented in 25% associated with symptoms of angina).

· 48-hour Holter monitoring identifies established atrial fibrillation (in about 10% of patients), paroxysmal

supraventricular arrhythmias (in 30%), non-sustained ventricular tachycardia (in 25%), and ventricular

tachycardia (in 25%). Ventricular tachycardia is invariably asymptomatic during Holter monitoring, but

the most useful risk marker of sudden death in adults. Sustained supraventricular arrhyth-mias are

often symptomatic and predispose to thromboembolic complications.

· Endomyocardial biopsy may be necessary to exclude specific heart muscle dis-order (amyloid, sarcoid)

but has no role in diagnosis because of the patchy nature of myofibrillar disarray.

What are the complications of hypertrophic cardiomyopathy?

· Sudden death.

· Atrial fibrillation.

· Infective endocarditis.

· Systemic embolization.

How would you manage such a patient?

· Relief of symptoms.

· Prevention of arrhythmias and sudden death by administration of amiodarone (Br Heart J 1985; 53:


· Improvement of ventricular function using a beta-blocker (propranolol up to 640 mg per day),

verapamil, amiodarone and diuretics (N Engl J Med 1997; 336: 775).

· Prevention of infective endocarditis.

· Dual-chamber pacing or DDD pacing (see p. 98) is considered by some to be the initial procedure in

symptomatic patients resistant to treatment with drugs. DDD pacing causes depolarization from the

right ventricular apex, resulting in altered motion of the interventricular septum and diminished

subaortic gradient.

· Septal ablation with alcohol or surgery - such as myotomy or myectomy -relieves symptoms but

does not alter the natural history of the disease. Mitral valve replacement may be done

simultaneously for severe mitral regurgitation.

· Counselling of sufferers and relatives is essential and they should be encouraged to contact the

Hypertrophic Cardiomyopathy Association.

What is the most characteristic pathophysiological abnormality in hypertrophic cardiomyopathy?

Diastolic dysfunction.

Which condition has the most common association with hypertrophic


Friedreich's ataxia.

What do you know about the genetics of hypertrophic


· Hypertrophic cardiomyopathy is an autosomal dominant heart muscle disorder.

· Mutations in the gene encoding contractile proteins cause disease in 50-60'7c of patients.

· There are mutations in the gene encoding for myofibrillary proteins: at least 9 individual genes have

been identified. Beta heavy chain myosin gene mutations are associated with left ventricular outflow

obstruction, whereas troponin T mutations are associated with rather modest left ventricular wall

thickening, and mutations in myosin binding protein C are associated with onset in late adult life. Arginine

gene mutations have a worse prognosis than leucine gene mutations.

What do you know about the Brockenbrough-Braunwald-Morrow sign?

Diminished pulse pressure in post-extrasystolic beat occurs in hypertrophic cardiomyopathy/aortic

stenosis (Circulation 1961: 23: 189-94).

What do you know about the epidemiology of this condition?

· The male to female ratio is equal, although the disease tends to affect younger men and older women.

· In children and adolescents, myocardial hypertrophy often occurs during growth spurts (a negative

diagnosis made before adolescent growth does not exclude the condition, and reassessment at a later

age is important).

· Myocardial hypertrophy does not ordinarily progress after adolescent growth is completed.

· Sudden death can occur at any age (from childhood to over 90 years) in subjects who have been

asymptomatic all their life. The annual mortality from sudden death is 3-5% in adults and at least 6% in

children and young adults.

· First-degree relatives of affected patients have a 50% chance of carrying the disease gene; they should

be investigated by ECG and two-dimensional echocardiogram. Genetic counselling is therefore important.

The pathology of hypertrophic cardiomyopathy was first described by two French pathologists in the mid

19th century and by a German pathologist in the early 20th century. The simultaneous reports of Sir

Russel Brock, thoracic surgeon at Guy's and Brompton Hospitals (Guy's Hosp Rep 1957; 106: 221-38),

and of Teare in 1958 brought the condition to modern medical attention (Br Heart J 1958; 20: 1).