Cardiomyopathies

Question 1

Most common type of cardiomyopathy

Answer 1

Dilated cardiomyopathy

Question 2

What is dilated cardiomyopathy

Answer 2

Characterised by dilation and impaired contractility of one or both ventricles resulting in reduced ejection fraction

Question 3

Clinical features of dilated cardiomyopathy

Answer 3

Dyspnoea
Orthopnoea
Paroxysmal nocturnal dyspnoea
S3 gallop

Mitral valve and tricuspid regard

Systolic murmur

Balloon appearance of heart on cxr

Question 4

Aetiology of dilated cardiomyopathy

Answer 4

Primary - genetics

secondary - viruses(coxsackie B), substances(cocaine, alcohol), CAD(ischaemic cardiomyopathy), valvular disease, arrhythmias

Question 5

Treatment for dilated cardiomyopathy

Answer 5

Similar to heart failure

Fluid restriction 
daily weights
diuretics 
ACEi
beta blockers 
heart transplant

Question 6

What is hypertrophic cardiomyopathy

Answer 6

Left ventricular hypertrophy with no chamber dilation

Question 7

What is primary hypertrophic cardiomyopathy caused by

Answer 7

Autosomal mutations of genes that code for sarcomere proteins(myosin heavy chain most common)

Question 8

Secondary causes of HOCM

Answer 8

Chronic hypertension(due to increase in afterload)

Aortic stenosis

Freidreich’s ataxia

Fabry’s disease

Question 9

What is freidreich’s ataxia

Answer 9

autosomal recessive neurodegenerative mutation of frataxin gene

Question 10

Two main types of HOCM

Answer 10

Obstructive type

Non-obstructive

Question 11

What is obstructive HOCM characterised by

Answer 11

LVH

Intraventricular septal hypertrophy

Question 12

Clinical manifestation of HOCM

Answer 12

Asymptomatic
Heart failure symptoms
Sudden cardiac death
Exercise exacerbates symptoms of intraventricular septal hypertrophy –> syncope, angina, dyspnoea

Question 13

Murmur in HOCM

Answer 13

Systolic crescendo-decrescendo murmur(similar to AS)

Increased by valsalva manoeuvre(reducing preload)

Reduced by hand grip or squatting(increasing afterload)

S4 gallop

Question 14

ECG findings in HOCM

Answer 14

Left ventricular hypertrophy

Deep Q waves

Question 15

IX of choice for HOCM

Answer 15

Doppler echo

Could do cardiac MRI in cases of uncertainty

Holter monitor to assess for arrhythmias

Question 16

Management of HOCM(ABCDE)

Answer 16

Amiodarone 
Beta-blockers or verapamil for symptoms 
Cardioverter defibrillator 
Dual chamber pacemaker 
Endocarditis prophylaxis

Question 17

Drugs to avoid in HOCM

Answer 17

Nitrates
ACE-inhibitors
Inotropes

Question 18

What is restrictive cardiomyopathy

Answer 18

Restrictive cardiomyopathy is a condition characterised by normal left ventricular cavity size and systolic function but with increased myocardial stiffness.

This makes the ventricle incompliant and fill predominantly in early diastole. It is often associated with raised left atrial pressure, atrial dilatation and sometimes arrhythmias.

Question 19

Causes of restrictive cardiomyopathy

Answer 19

Idiopathic 
Endomyocardial fibrosis associated with loffler's syndrome 
Infiltrative myocardial disease 
Amyloid heart disease 
Sarcoidosis 
Haemochromatosis

Question 20

Presentation of restrictive cardiomyopathy

Answer 20

Usually presents with heart failure but normal systolic function: dyspnoea, fatigue, loud third heart sound, pulmonary oedema, murmurs due to valve incompetence.

Heart size is usually normal or slightly enlarged.

Features of right ventricular failure predominate: raised JVP, with prominent x and y descents, hepatomegaly, oedema, ascites.

Up to 75% of patients with idiopathic restrictive cardiomyopathy develop atrial fibrillation

Question 21

Gold-standard diagnostic test for restrictive cardiomyopathy

Answer 21

The gold-standard diagnostic test is right ventricular biopsy, which demonstrates positivity for Congo red staining

Question 22

Management of restrictive cardiomyopathy

Answer 22

In children, restrictive cardiomyopathy is primarily idiopathic, and transplantation is the treatment of choice.

Management of heart failure

Amiodarone can reduce ventricular arrhythmias in high-risk patients.

All patients with restrictive cardiomyopathy and atrial fibrillation should be anticoagulated unless contra-indicated

Beta-blockers and non-dihydropyridine calcium-channel blockers may be used for rate control in those with atrial fibrillation

Question 23

Intervention for high risk patients with restrictive cardiomyopathy

Answer 23

Implantable cardioverter defibrillator: to prevent sudden death in high-risk patients

Question 24

Causes of inherited dilated cardiomyopathy

Answer 24

either a familial genetic predisposition to DCM or a specific syndrome e.g. Duchenne muscular dystrophy

Majority of defects are inherited in an autosomal dominant fashion although other patterns of inheritance are seen

Question 25

JVP in cardiac tamponade vs constrictive pericarditis

Answer 25

Cardiac tamponade - Asent Y descent

Constrictive pericarditis - X + Y present

TAMponade = TAMpaX

Question 26

What is arrhythmogenic right ventricular cardiomyopathy

Answer 26

is a form of inherited cardiovascular disease which may present with syncope or sudden cardiac death.

Question 27

Pathophys of arrhythmogenic right ventricular cardiomyopathy

Answer 27

inherited in an autosomal dominant pattern with variable expression

the right ventricular myocardium is replaced by fatty and fibrofatty tissue

around 50% of patients have a mutation of one of the several genes which encode components of desmosome

Question 28

ECG changes in arrhythmogenic right ventricular cardiomyopathy

Answer 28

ECG abnormalities in V1-3, typically T wave inversion. An epsilon wave is found in about 50% of those with ARV - this is best described as a terminal notch in the QRS complex

Question 29

Management of arrhythmogenic right ventricular cardiomyopathy

Answer 29

drugs: sotalol is the most widely used antiarrhythmic
catheter ablation to prevent ventricular tachycardia
implantable cardioverter-defibrillator