Cardiomyopathy Flashcards
1
Q
what is cardiomyopathy?
A
heart muscle disorder without coronary artery disease, hypertension, valvular or congenital heart diseases
2
Q
prognosis
A
varying prognoses
can be asymptomatic to severe life-limiting and life threatening
some are associated with sudden cardiac death
3
Q
types
A
dilated cardiomyopathy
hypertrophic cardiomyopathy
restrictive cardiomyopathy
4
Q
epidemiology
A
can occur at younger age
suspect in any patient presenting with heart failure
hypertrophic cardiomyopathy is the most common cause of unexpected death in childhood
often genetic link
5
Q
causes
A
primary = idiopathic secondary = has a cause
6
Q
secondary causes
A
connective tissue disorders endocrine disorders drugs infection nutrition genetics
7
Q
connective tissue disorders that cause cardiomyopathy
A
sarcoidosis
SLE
8
Q
endocrine disorders that cause cardiomyopathy
A
diabetes
thyroid disease
acromegaly
9
Q
drugs that cause cardiomyopathy
A
chemotherapeutic agents
cocaine
alcohol
10
Q
nutrition causes of cardiomyopathy
A
obesity
vitamin B1 deficiency
calcium deficiency
magnesium deficiency
11
Q
genetic causes of cardiomyopathy
A
duchenne muscular dystrophy
12
Q
clinical divisions of cardiomyopathy
A
dilated
hypertrophic
restrictive
arrhythmogenic right ventricular
13
Q
what is dilated cardiomyopathy?
A
most common type of cardiomyopathy enlarged ventricular normal wall thickness normal systolic function affects left or both ventricles most common indication for heart transplant
14
Q
epidemiology of dilated cardiomyopathy
A
2/10,000
often in genetically susceptible individuals
typically presents in 20-60 year olds
more common in men and africans
15
Q
causes of dilated cardiomyopathy
A
ischaemic heart disease alcohol cocaine use thyroid disorder valvular disease genetic causes idiopathic infection autoimmune disorders connective tissue disorders granulomatous disorders drugs peripartum - poor prognosis
16
Q
infective causes of cardiomyopathy
A
bacterial
HIV
viral - coxsackie or viral myocarditis
17
Q
pathophysiology of dilated cardiomyopathy
A
damage to myocardium
some myocardial cells undergo necrosis
chronic fibrosis
remaining myocardial tissue dilates and hypertrophies to compensate for necrosis and fibrosis
18
Q
what can occur as a result of hypertrophy?
A
mitral or tricuspid regurgitation
atrial fibrillation - and other arrhythmias
AV node block as a result of atrial dilatation
thrombus formation in large dilated chambers
19
Q
onset
A
gradual except when acute myocarditis is the cause
20
Q
presentation of dilated cardiomyopathy
A
heart failure: dyspnoea - exertional fatigue peripheral oedema raised JVP - if RV involved loud 3rd and 4th heart sounds arrhythmia thromboembolism - PE/stroke acute myocarditis
21
Q
what investigations need to be done for dilated cardiomyopathy?
A
ECG CXR echocardiogram coronary angiogram cardiac muscle biopsy
22
Q
ECG changes dilated cardiomyopathy
A
sinus tachycardia
T wave inversion and Q waves - even in absence of previous MI
ST depression
left BBB
23
Q
CXR dilated cardiomyopathy
A
enlarged heart
heart failure
pleural effusion
24
Q
Echo dilated cardiomyopathy
A
dilated chambers
hypokinetic chambers
used to rule out primary valve disorders
can detect a mural thrombus
25
coronary angiogram dilated cardiomyopathy
may be considered when there is doubt over diagnosis, potentially ischaemic heart disease or ischaemic heart disease is the cause
26
cardiac muscle biopsy dilated cardiomyopathy
rarely performed
| considered if there a specific cause is suspected such as myocarditis, amyloidosis or sarcoidosis
27
management of dilated cardiomyopathy
```
treat reversible causes
prophylactic anticoagulation
treat arrhythmias
consider pacemaker for AVN block
treat like heart failure
consider implantable cardioverter defibrillator for patients at high risk of arrhythmia
consider heart transplant
```
28
treating potential reversible causes of dilated cardiomyopathy
toxoplasmosis
haemochromatosis
thyrotoxicosis
29
prophylactic anticoagulation for dilated cardiomyopathy
warfarin
| DOACs
30
when to consider heart transplant for dilated cardiomyopathy?
younger patients - <60
| 70% 5-year survival
31
prognosis of dilated cardiomyopathy
poor
progression results in worsening heart failure
70% mortality in 5 years
sudden death due to thrombus formation or sudden arrhythmia
32
what worsens dilated cardiomyopathy prognosis?
ventricular wall is thin
| ventricles are markedly dilated
33
what improves dilated cardiomyopathy prognosis?
ventricular wall maintains normal thickness
| less dilated
34
what is hypertrophic cardiomyopathy?
autosomal dominant genetic disorder
causes diastolic dysfunction with or without outflow obstruction
common cause of sudden death in young athletes
35
what does hypertrophic cardiomyopathy cause?
hypertrophy of left ventricle causing left ventricular outflow obstruction, mitral valve problems, myocardial ischaemia and risk of tachyarrhythmias
36
epidemiology of hypertrophic cardiomyopathy
```
most common genetic cardiac disease
1/500
more common in men and black people
obstructive = 25% of cases
most common cause of sudden cardiac death in young people
```
37
age of presentation of hypertrophic cardiomyopathy
between 20-40
38
what causes hypertrophic cardiomyopathy?
mutation in any 1 or more of 12 genes that code for cardiac proteins
most significant = troponin T mutations, most likely to cause sudden cardiac death
39
inheritance of hypertrophic cardiomyopathy
autosomal dominant inheritance
| variable penetrance and expressivity
40
pathophysiology of hypertrophic cardiomyopathy
genetic defects in genes coding for cardiac proteins causing disorganised cardiac matrix and left ventricular hypertrophy
hypertrophy can occur in any part of the left ventricle
most commonly affects anterior ventricular septum
41
which proteins are affected in hypertrophic cardiomyopathy?
beta-myosin heavy chain
troponin
alpha-tropomyosin
42
presentation of hypertrophic cardiomyopathy
```
mostly asymptomatic
symptoms:
dyspnoea - can be initiated by alcohol
chest pain
syncope on exercise
palpitations
sudden death
family history
```
43
syncope in hypertrophic cardiomyopathy
can be initiated by alcohol
| can be seemingly unexplained
44
sudden death from hypertrophic cardiomyopathy
can be due to arrhythmia or due to outflow tract obstruction
unexplained syncope is a risk factor for sudden death
45
examination for hypertrophic cardiomyopathy
can be normal or abnormal
46
abnormal examination findings for hypertrophic cardiomyopathy
forceful apex beat
late ejection systolic murmur exacerbated by valsalva manoeuvre and reduced by squatting
prominent JVP
abnormal blood pressure response to exercise - may fall or rise very little
atrial fibrillation - occurs in 20%
47
what should happen to BP on exercise?
rise by 20-25mmHg
48
investigations for hypertrophic cardiomyopathy
```
ECG
Echo
CXR
Cardiac MRI
myocardial biopsy
cardiac catheterisation
```
49
ECG changes in hypertrophic cardiomyopathy
```
non-specific
ST segment changes
T wave inversion
signs of left ventricular hypertrophy
atrial fibrillation
```
50
Echo in hypertrophic cardiomyopathy
```
standard diagnostic test
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
```
51
CXR in hypertrophic cardiomyopathy
often normal
heart size may be normal or enlarged
left atrial enlargement seen in mitral regurgitation
52
cardiac MRI in hypertrophic cardiomyopathy
assessing segmental hypertrophy
| can assess systolic and diastolic dysfunction
53
myocardial biopsy for hypertrophic cardiomyopathy
used to rule out other conditions
54
cardiac catheterisation for hypertrophic cardiomyopathy
assesses the degree of outflow obstruction and other structural abnormalities
55
aims of management for hypertrophic cardiomyopathy
reduce symptoms
| reduce progression of disease
56
management of hypertrophic cardiomyopathy
control arrhythmias
anticoagulation for AF
reduce outflow tract obstruction gradient and improve diastolic function
disopyramide used in severe cases
implantable cardioverter defibrillator for those at risk of sudden death
avoid competitive sports and strenuous exercise
surgical myectomy
heart transplatn for severe heart failure
57
controlling arrhythmias in hypertrophic cardiomyopathy
anti-arrhythmic drugs
| ablation therapy
58
how to reduce outflow tract obstruction gradient and improve diastolic function
beta blockers
verapamil
reduce cardiac contractility and dilate hypertrophied left ventricle, reduce outflow tract obstruction and improve diastolic function
improve physical function of heart but do not treat arrhythmias
59
disopyramide
negative inotrope
60
what should we be wary of in hypertrophic cardiomyopathy management?
```
drugs that reduce preload, as it decreases the chamber size and can exacerbate symptoms
ACE inhibitors
ARBs
nitrites
diuretics
```
61
surgical myectomy in hypertrophic cardiomyopathy
patients with symptoms resistant to medical management can be managed with resection of the hypertrophied muscle to reduce outflow tract obstruction
62
mortality risk if hypertrophic cardiomyopathy
annual = 1-3%
higher risk if younger age at presentation
sudden death is most common cause of death
typically sudden death occurs in young patients with few or no symptoms
63
risk factors for sudden death in hypertrophic cardiomyopathy
```
unexplained syncopal events
episode of ventricular fibrillation or ventricular tachycardia
abnormal BP response to exercise
family history of sudden cardiac death
under 30
```
64
how to prevent sudden death in hypertrophic cardiomyopathy
intra-cardiac devices
65
when to use ICDs in hypertrophic cardiomyopathy?
secondary prevention in any patient who has had a cardiac arrest or previous episode of sustained VT
66
good prognosis for hypertrophic cardiomyopathy
patients with LVH wall thickness of <20mm and no other risk factors/ low risk have a similar life expectancy to general population
67
risk of infective endocarditis
low
| no need for antibiotic prophylaxis
68
what is restrictive cardiomyopathy?
reduced compliance of ventricular walls during diastolic filling
most commonly affects LV but can affect both
69
how common is restrictive cardiomyopathy?
least common of the cardiomyopathies
70
types of restrictive cardiomyopathy
1. infiltration of myocardium by an invasive substance such as amyloid plaques, sarcoidosis or iron in haemochromatosis
2. fibrotic myocardium - no external invasive substance
71
what can restrictive cardiomyopathy cause?
high diastolic filling pressures
leads to pulmonary hypertension
associated with mural thrombi
72
epidemiology of restrictive cardiomyopathy
most patients are elderly
equal affect on genders
not inherited
more prevalent in tropical regions
73
causes of restrictive cardiomyopathy
```
no underlying cause
lofflers syndrome
amyloidosis most common in western world
sarcoidosis
haemochromatosis
```
74
lofflers syndrome
tropical disease
starts with arteritis which spreads to cause thrombus formation of the endocardium and valves
leads to fibrosis
75
presentation of restrictive cardiomyopathy
```
heart failure signs
normal/enlarged heart
features of right ventricular failure
similar presentation to constrictive pericarditis
AF in 75% of patients
other arrhythmias - AVN block etc.
```
76
signs of heart failure associated with restrictive cardiomyopathy
```
dyspnoea - exertional
orthopnoea
fatigue
pulmonary oedema
loud 3rd heart sound
```
77
features of right ventricular failure associated with restrictive cardiomyopathy
raised JVP
hepatomegaly
oedema
ascites
78
investigations for restrictive cardiomyopathy
ECG
CXR
echo
79
ECG changes in restrictive cardiomyopathy
non-specific T wave and ST changes
pathological Q waves in absence of previous MI
Left ventricular hypertrophy
80
CXR changes in restrictive cardiomyopathy
heart size is often normal or small
| may be enlarged in late stage amyloidosis or haemochromatosis
81
Echo changes in restrictive cardiomyopathy
normal systolic function
dilated atria
myocardial hypertrophy - increased wall thickness
can help differentiate from restrictive pericarditis
82
restrictive pericarditis echo
thickened pericardium
83
treatment aim for restrictive cardiomyopathy
treat underlying cause
early treatment for major underlying causes may reduce disease progression
no specific cardiac medical treatments
some cases suitable for endocardial resection
heart transplant
84
prognosis of restrictive cardiomyopathy
poor
similar to dilated cardiomyopathy
30% 5 year survival
no effective treatments for most patients that alter the cause of disease
85
cautions in restrictive cardiomyopathy
diuretics
digoxin
nitrites
86
why is caution taken with diuretics in restrictive cardiomyopathy?
reduce preload
| stiff ventricles rely on preload for filling
87
why is caution taken with digoxin in restrictive cardiomyopathy?
amyloidosis patients have extreme digoxin sensitivity and can become easily toxic
88
why is caution taken with nitrites in restrictive cardiomyopathy?
can reduce afterload and cause dangerous hypotension
89
differential diagnoses for cardiomyopathy
```
ischaemic heart disease
valvular heart disease - mitral and aortic valves
athletes
pericarditis
pulmonary stenosis
VSD
```
90
type of dysfunction in dilated cardiomyopathy
systolic
91
type of dysfunction in hypertrophic cardiomyopathy
diastolic potentially plus outflow obstruction
92
type of dysfunction in restrictive cardiomyopathy
diastolic
