Cardiomyopathy

Question 1

Cardiomyopathy definition

Answer 1

Heart muscle disorder

Question 2

Cardiomyopathy types

Answer 2

Dilated
Hypertrophic
Restrictive
Arrhythmogenic right ventricular cardiomyopathy (ARVC)

Question 3

Cardiomyopathy epidemiology

Answer 3

Can occur at younger age
Suspect if presenting with CCF
Hypertrophic = most common cause of unexpected death in childhood
Often genetic component

Question 4

Cardiomyopathy causes

Answer 4

Connective tissue disorders
Endocrine - diabetes, thyroid
Drugs - chemo, cocaine, alcohol
Infection
Nutrition - obesity, vit B1, Ca, Mg deficiencies
Genetic - duchenne muscular dystrophy

Question 5

Dilated cardiomyopathy (DCM) epidemiology

Answer 5

Most common type
Enlarged ventricular size, with normal ventricular wall thickness and systolic dysfunction
Left or both ventricles
Most common indication for heart transplant
Men and Africans and genetic link

Question 6

DCM causes

Answer 6

Ischaemic heart disease
Alcohol
Cocaine
Thyroid
Valvular disease
Genetic
Idiopathic
Infection - bacterial, HIV, coxackie virus, viral myocarditis
Autoimmune
CT disorder
Granulomatous disorder
Drug
Peripartum in pregnancy -poor prognosis

Question 7

DCM pathophysiology

Answer 7

Damage to myocardium
Necrosis of myocardial cells
Chronic fibrosis
Remaining tissue dilates and hypertrophies to compensate
Link with mitral/tricuspid regurgitation
Can lead to AF, thrombus formation

Question 8

DCM presentation

Answer 8

SOB
Fatigue
Peripheral oedema
Raised JVP
Loud S3 and S4
Arrythmia
Thromboembolism
Acute myocarditis
Heart failure

Question 9

DCM ECG

Answer 9

Sinus tachycardia
T wave inversion
Pathological Q waves
ST depression
LBBB

Question 10

DCM investigations

Answer 10

ECG
CXR
Echo
Coronary angiogram if ischaemic heart disease suspected
Cardiac muscle biopsy if specific cause suspected

Question 11

DCM CXR

Answer 11

Enlarged heart
Signs of heart failure
Pleural effusion

Question 12

DCM echo

Answer 12

Dilated hypokinetic chambers
Rule out valve disorders
Check for thrombus

Question 13

DCM management

Answer 13

Tx for reversible causes
Prophylactic anticoagulation
Treat arrhythmia
Consider pacemaker if block /ICD for arrhythmia
Treat as for heart failure
- ACEi/ARB
- +/- Beta blocker
- Diuretics - loop and thiazide, spironolactone
- Nitrates
Consider heart transplant

Question 14

DCM prognosis

Answer 14

70% mortality within 5 years
Worse if:
Ventricular wall is thin
Ventricles markedly dilated

Question 15

Hypertrophic cardiomyopathy (HCM) definition

Answer 15

Autosomal dominant genetic disorder that causes diastolic dysfunction, with or without outflow obstruction
Can cause sudden cardiac death in young athletes
LV hypertrophy - LV outflow obstruction, mitral valve problems, myocardial ischaemia and tachyarrhythmias

Question 16

HCM causes

Answer 16

Autosomal dominant - variable penetrance and expressivity
Mutation in one+ of 12 genes that code for cardiac proteins - esp troponin T mutations

Question 17

HCM pathophysiology

Answer 17

Genetic defect in codes for cardiac proteins (beta-myosin heavy chain, troponin, alpha-tropomyosin)
Disorganised cardiac matrix
LV hypertrophy, esp in ant ventricular septum

Question 18

HCM presentation

Answer 18

Asymptomatic
SOB
Chest pain
Syncope on exercise/alcohol
Palpitations
Sudden death, esp if experiencing syncope, due to outflow tract obstruction or arrhythmia
FH
Aortic stenosis / coronary artery disease

Question 19

HCM examination

Answer 19

Forceful apex beat
Late ejection systolic murmur
- reduced when squatting
Prominent JVP
Abnormal BP response to exercise - no rise in BP
AF

Question 20

HCM investigations

Answer 20

ECG
Echo - standard diagnostic test
CXR
Cardiac MRI
Myocardial biopsy
Cardiac catherisation

Question 21

HCM ECG

Answer 21

ST changes
T wave inversion
LVH
AF

Question 22

HCM echo

Answer 22

Asymmetric septal hypertrophy > 15mm
Ratio of septal wall to posterior wall > 1.4:1
Non-dilated left ventricular cavity
Normal systolic function
Absence of valvular disease

Question 23

HCM management

Answer 23

Beta blockers
Verapamil
Reduce cardiac contractibility - dilate LV
Beware of ACEi, ARB, nitrites, diuretics
Reduce preload - decrease chamber size - exacerbate symptoms
ICD
Avoid sports or strenuous exercise
Surgical myectomy
Heart transplant

Question 24

Risk factors for sudden cardiac death

Answer 24

Unexplained syncopal events
Episodes of VF or VT
Abnormal BP response to exercise
FH
Age < 30

Question 25

Restrictive cardiomyopathy definition

Answer 25

Reduced compliance of ventricular walls during diastolic filling
Type 1 - infiltration of myocardium by invasive substance (amyloid plaques, sarcoidosis, iron in haemochromatosis)
Type 2 - fibrotic myocardium
Leads to high diastolic filling pressures and so pulmonary hypertension
Associated with mural thrombi

Question 26

RCM aetiology

Answer 26

Idiopathic
Lofflers syndrome - tropical disease
Amyloidosis
Sarcoidosis
Haemochromatosis

Question 27

RCM presentation

Answer 27

CCF signs
Heart size enlarged
RVF signs - raised JVP, hepatomegaly, oedema, ascites
AF and other arrhythmias
Similar to constrictive pericarditis symptoms

Question 28

RCM ecg

Answer 28

Non-specific T and ST changes
Pathological Q waves
LVH

Question 29

RCM CXR

Answer 29

Heart size normal or small

Question 30

RCM echo

Answer 30

Normal systole
Dilated atria
Myocardial hypertrophy
Differentiate from restrictive pericarditis - thickened pericardium

Question 31

RCM medications not to give

Answer 31

Diuretics - reduce preload
Digoxin - sensitivity in amyloidosis pts
Nitrites - reduce after load - hypotension

Question 32

RCM management

Answer 32

Tx underlying cause
Endocardial resection
Heart transplant

Question 33

Cardiomyopathy differentials

Answer 33

Ischaemic heart disease
Valvular heart disease - esp mitral and aortic
Athletes
Pericarditis
Pulmonary stenosis
VSD