Cardiovascular 2 Flashcards
what is a cardiomyopathy?
a group of diseases of the myocardium that affect the mechanical or electrical function of the heart
what are the 4 types are cardiomyopathy?
hypertrophic
dilated
restricted
arrythmogenic right ventricular
what is dilated cardiomyopathy?
Dilated cardiomyopathy (DCM) is the most common form of cardiomyopathy, accounting for 90% of cases.
- dilated heart leading to predominately systolic dysfunction
- all 4 chambers are dilated, but the left ventricle more so than right ventricle
- eccentric hypertrophy (sarcomeres added in series) is seen
what causes dilated cardiomyopathy ?
idiopathic = the most common cause
myocarditis: e.g. Coxsackie B, HIV, diphtheria, Chagas disease
ischaemic heart disease
peripartum
hypertension
iatrogenic: e.g. doxorubicin
substance abuse: e.g. alcohol, cocaine
inherited: either a familial genetic predisposition to DCM or a specific syndrome e.g. Duchenne muscular dystrophy
around a third of patients with DCM are thought to have a genetic predisposition
a large number of heterogeneous defects have been identified
the majority of defects are inherited in an autosomal dominant fashion although other patterns of inheritance are seen
infiltrative e.g. haemochromatosis, sarcoidosis
wet beriberi - thiamine deficiency
what are the features of dilated cardiomyopathy?
classic findings of heart failure
systolic murmur: stretching of the valves may result in mitral and tricuspid regurgitation
S3
‘balloon’ appearance of the heart on the chest x-ray
what investigations would you perform for cardiomyopathy?
- ECG - often non-specific findings
- CXR - enlarged heart silhouette
- Echo - 4 chamber cardiac enlargement, poor systolic function with diminished stroke volume and low ejection fraction
- FBC - low Hb or haematocrit levels
- BNP - raised in heart failure
how do you manage dilated cardiomyopathy?
manage heart failure and AF in conventional way
what is hypertrophic obstructive cardiomyopathy?
Hypertrophic obstructive cardiomyopathy (HOCM) is an autosomal dominant disorder of muscle tissue caused by defects in the genes encoding contractile proteins. The estimated prevalence is 1 in 500. HOCM is important as it is the most common cause of sudden cardiac death in the young.
- the most common defects involve a mutation in the gene encoding β-myosin heavy chain protein or myosin-binding protein C
- results in predominantly diastolic dysfunction
left ventricle hypertrophy → decreased compliance → decreased cardiac output
-characterized by myofibrillar hypertrophy with chaotic and disorganized fashion myocytes (‘disarray’) and fibrosis on biopsy
what are the features of hypertrophic obstructive cardiomyopathy ?
- often asymptomatic
- exertional dyspnoea
- angina
- syncope - typically following exercise due to subaortic hypertrophy of the ventricular septum, resulting in functional aortic stenosis
- sudden death (most commonly due to arrhythmias)
- arrhythmias
- heart failure
- jerky pulse, JVP with a large ‘a’ waves, double apex beat
- ejection systolic murmur
- S4 gallop
associated with friedreich’s ataxia and wolff-parkinson white
what would an echo show in someone with hypertrophic obstructive cardiomyopathy?
Echo findings - mnemonic - MR SAM ASH
mitral regurgitation (MR)
systolic anterior motion (SAM) of the anterior mitral valve leaflet
asymmetric hypertrophy (ASH)
what would an ECG show in someone with hypertrophic obstructive cardiomyopathy?
left ventricular hypertrophy
non-specific ST segment and T-wave abnormalities, progressive T wave inversion may be seen
deep Q waves
atrial fibrillation may occasionally be seen
how is hypertrophic obstructive cardiomyopathy managed?
Management - ABCDE Amiodarone Beta-blockers or verapamil for symptoms Cardioverter defibrillator Dual chamber pacemaker Endocarditis prophylaxis*
Drugs to avoid
nitrates
ACE-inhibitors
inotropes
what are the features of restrictive myocarditis?
may be asymptomatic or present with symptoms of cardiac failure
what are some causes of restrictive cardiomyopathy?
amyloidosis
post-radiotherapy
Loeffler’s endocarditis
what are examples of genetic cardiomyopathies?
Genetic - both conditions listed below are autosomal dominant. An implantable cardioverter-defibrillator is often inserted to reduce the incidence of sudden cardiac death.
they are primary cardiomyopathies which predominantly involve the heart
what are examples of mixed cardiomyopathies?
Mixed - rather confusingly most of the causes of dilated and restrictive cardiomyopathy are now listed separately in the ‘secondary’ causes. This category servers as a reminder that many patients will have a genetic predisposition to cardiomyopathy which is then triggered by the secondary process, hence the ‘mixed’ category
what are some causes of secondary cardiomyopathies?
- infective - coaxsackie B virus, Chagas disease
- infiltrative - amyloidosis
- storage - haemochromatosis
- Toxicity - doxorubicin, alcoholic cardiomyopathy
- inflammatory - granulomatosis - sarcoidosis
- endocrine - DM, thyrotoxicosis, acromegaly
- Neuromuscular - Friedreich’s ataxia, Duchenne, myotonic dystrophy
- nutritional deficiency - berberi - thiamine
- autoimmune - SLE
what is arrhythmogenic right ventricular cardiomyopathy?
Arrhythmogenic right ventricular cardiomyopathy (ARVC, also known as arrhythmogenic right ventricular dysplasia or ARVD) is a form of inherited cardiovascular disease which may present with syncope or sudden cardiac death. It is generally regarded as the second most common cause of sudden cardiac death in the young after hypertrophic cardiomyopathy.
AD inheritance
the right ventricular myocardium is replaced by fatty and fibrofatty tissue
how does arrhythmogenic right ventricular present?
palpitations
syncope
sudden cardiac death after physical exertion
chest pain
dizziness
fatigue
usually in males - first presentation in adolescence
they may have normal cardiac exam, s3, s4 or split s2 may be present
what investigations would you perform for arrhythmogenic right ventricular cardiomyopathy?
- 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
- echo changes are often subtle in the early stages but may show an enlarged, hypokinetic right ventricle with a thin free wall
- MRI is useful to show fibrofatty tissue
what management would you perform for arrhythmogenic right ventricular cardiomyopathy?
drugs: sotalol is the most widely used antiarrhythmic
catheter ablation to prevent ventricular tachycardia
implantable cardioverter-defibrillator
what is naxos disease?
an autosomal recessive variant of ARVC
a triad of ARVC, palmoplantar keratosis, and woolly hair
what are types of acquired cardiomyopathy?
peripartum cardiomyopathy
Takotsubo cardiomyopthy
what is peripartum cardiomyopathy?
Typical develops between last month of pregnancy and 5 months post-partum
More common in older women, greater parity and multiple gestations
what is Takotsubo cardiomyopathy?
‘Stress’-induced cardiomyopathy e.g. patient just found out family member dies then develops chest pain and features of heart failure
they will be ST elevation but normal coronary angiogram
Transient, apical ballooning of the myocardium
Treatment is supportive
what is acute pericarditis?
- inflammation of the pericardium
- new onset of inflammation lasting less than 4-6 weeks
- it can be either fibrinous or effusive with a purulent, serous or haemorrhagic exudate
what are the features of pericarditis?
it is characterised by a triad of chest pain, pericardial friction rub and serial ECG changes
- the chest pain is usually pleuritic - and often relieved by sitting forward
- non productive cough
- dyspnoea
- flu like symptoms
- tachypnoea
- tachycardia
what are some causes of acute pericarditis?
viral infections (Coxsackie) tuberculosis uraemia (causes 'fibrinous' pericarditis) trauma post-myocardial infarction, Dressler's syndrome connective tissue disease hypothyroidism malignancy idiopathic
what investigations would you perform for acute pericarditis?
ECG changes
the changes in pericarditis are often global/widespread, as opposed to the ‘territories’ seen in ischaemic events
‘saddle-shaped’ ST elevation
PR depression: most specific ECG marker for pericarditis
transthoracic echo
serum troponins, ESR, CRP, FBC, UREA
pericardial fluid/blood culture
how is acute pericarditis managed?
treat the underlying cause
a combination of NSAIDs and colchicine is now generally used for first-line for patients with acute idiopathic or viral pericarditis
if there is tamponade or symptomatic effusion - pericardiocentesis
if it is purulent - pericardiocentesis and antibiotics - vancomycin and ceftriaxone
what can cause constrictive pericarditis?
any cause of pericarditis but particularly TB
what are the features of constrictive pericarditis?
dyspnoea right heart failure: elevated JVP, ascites, oedema, hepatomegaly JVP shows prominent x and y descent pericardial knock - loud S3 Kussmaul's sign is positive
CXR - will show pericardial calcification
how can you distinguish between constrictive pericarditis and cardiac tamponade?
cardiac tamponade
JVP - absent Y descent
Pulsus paradoxus - present
Kaussmaul’s sign - rare
Constrictive pericarditis JVP - X + Y present pulsus paradoxus - absent Kussmaul's sign - present preicardial calcification on CXR
what is cardiac tamponade?
Cardiac tamponade is characterized by the accumulation of pericardial fluid under pressure.
what are the features of cardiac tamponade?
Classical features - Beck’s triad:
hypotension
raised JVP
muffled heart sounds
Other features:
dyspnoea
tachycardia
an absent Y descent on the JVP - this is due to the limited right ventricular filling
pulsus paradoxus - an abnormally large drop in BP during inspiration
Kussmaul’s sign - much debate about this
ECG: electrical alternans
what investigations would you perform for cardiac tamponade?
- ECG - low voltage, electrical alternans, electromechanical dissociation associated with end stage tamponade
- Transthoracic echo - large pericardial effusion, chamber collapse and respiratory variation of ventricular filling
- CXR - enlarged heart
- FBC, ESR, cardiac enzymes
how is cardiac tamponade managed?
pericardiocentesis
or surgical drainage
how do you manage recurrent pericarditis?
NSAIDs plus PPI plus colchicine
2nd line corticosteroid
3rd line immunosupressant
what is an aneurysm?
defined as abnormal dilation of a blood vessel by more than 50% of its normal diameter
what is an abdominal aortic aneurysm?
An abdominal aortic aneurysm (AAA) is defined as a dilatation of the abdominal aorta greater than 3cm
they can be true or false aneurysm
true - all 3 layers of the arterial wall are involved
false - only a single layer of fibrous tissue forms the aneurysm wall
*it is important to identify and manage early