Cardiomyopathy, myocarditis & pericarditis Flashcards
What are the types of cardiomyopathy
Hypertrophic
Dilated
Restrictive
Myocarditis
What is dilated cardiomyopathy?
Chambers of the heart dilate (funnily enough)
Meaning the volume increases, but this leaves the heart walls relatively thin
How does heart muscle develop in dilated cardiomyopathy?
As the muscle walls dilate over time, new sarcomeres are added in series
Which chambers of the heart are affected more in DCM?
Ventricles
All 4 chambers of the heart can dilate though
What are the general causes of DCM?
Idiopathic
Ischaemia & valvular diseases
Arrhythmias
Genetic & familial causes
Infection, inflammatory, autoimmune, postpartum causes
Toxic damage
Injury, cell loss, scar replacement
What are the genetic / familial causes of DCM?
SCN5A gene mutations
Muscular dystrophy (Duchenne)
Haemaochromatosis
What toxic damage can cause DCM?
Chemotherapy (doxorubicin)
Cocaine
Alcohol
Exogenous chemicals
Endocrine stuff
What infections or diseases can cause DCM?
Sarcoidosis
Causes of myocarditis eg:
- Coxsackievirus B
- Chagas disease from south america
What does postpartum DCM mean?
= Pregnancy
DCM can occur in third trimester or just after the mother gives birth
What are the symptoms of DCM?
Progressive, slow development of:
Dyspnoea Orthopnoea PND - paroxysmal nocturnal dyspnoea Cough Ankle swelling Weight gain
(symptoms of heart failure)
If someone presents with symptoms indicating DCM, what important points should you get from the past medical history?
Systemic illness
Hypertension
Vascular disease
Thyroid problems
Neuromuscular disease
What important points for DCM should you get from the family & social history?
Incidence of DCM or other cardiomyopathy
Recent travel to spicy overseas places
Alcohol intake
Occupational history
What signs on inspection would indicate DCM?
SOB (tachypnoea) at rest
Elevated JVP
Poor superficial perfusion
Ankle oedema
Sacral oedema (if they’ve been lying down for a while)
What signs on palpation would indicate DCM?
Thready, narrow pulse
Irregular pulse if in AF
Displaced apex beat
Increased Cap refill
Hepatomegally
Ascites
When auscultating a patient, what signs would indicate DCM?
Mitral regurgitation murmur
S3 and S4 heart sounds
Crackles (pulmonary oedema, pleural effusions)
What investigations should be done for DCM?
Repeat ECGs CXR CMRI Bloods (FBC, U+Es) N termial pro Brain Natriuetic Peptide ECHO Coronary angiogram
What general measures are taken to patient care in DCM?
Correct anaemia
Remove exacerbating drugs eg NSAIDs
Correct any endocrine disturbance
Advise on fluid and salt intake, reduce it
Advise on managing weight to identify fluid overload
HF nurse referral
What drugs can be given to patients for DCM?
ACEI, ATII blockers, diuretics
Beta blockers
Spironolactone
Anticoagulants as required
What surgical management is available for DCM?
SCD risk assessment with ICD or CRT-D/P implant
Cardiac transplant
Which type of DCM has the best prognosis?
Postpartum DCM (pregnancy)
Which DCM has the worst prognosis?
DCM due to HIV infection
<20% survive past 10 years
What is the effect of Restrictive cardiomyopathy?
Reduced compliance of heart muscle
Reduced filling of heart means less blood pumped out
= Diastolic heart failure
What are the causes of RCM?
50% idiopathic
Non infiltrative; Familial, forms of HCM, Scleroderma, diabetic, pseudoxanthoma elasticum
Infiltrative; Amyloid, Sarcoid
Storage diseases; Haemachromatosis, Fabry disease
Endomyocardial; Fibrosis, carcinoid, radiation, drug effects
Summarise the basic investigation for RCM
Repeated ECG
CXR
N termial pro Brain Natriuetic Peptide
Basic bloods (FBC, U+Es)
Auto antibodies
Fabry; low plasma alpha galactosidase A activity
Echo
CMRI
Biopsy more helpful but still has high false negative rate
Which imaging method is best for identifying Cardiomyopathies?
CMRI
Why is taking bloods useful for identifying RCM?
Can identify Sarcoid causes and haemachromatosis
Why is autoantibodies a useful test for RCM?
Identifies sclerotic connective tissue diseases
If investigations indicate an Amyloid cause for RCM, what must be done to confirm the diagnosis?
Amyloid needs non cardiac biopsy to help establish the diagnosis
How is RCM pharmacologically managed?
Limited diuretic use as low filling pressures will cause problems
Beta blockers limited ACEI use
Anticoagulants as required
How is RCM surgically managed?
SCD risk assessment with ICD or CRT-D/P implant
Cardiac transplant
What mutation is associated with hypertrophic cardiomyopathy?
Sarcomeric protein gene mutation accounts for 40-60% of cases
Autosomal dominant gene but has varied expression and incomplete penetrance so often does not show
Most often MYBPC3, MYH7
How does cardiac muscle differ in someone with HCM
Sarcomeres added in parallel
Can be generalised or segmental thickness, so it may just be apical or septal areas that are fucking huge
Histologically, mad disarray of cells so it doesnt look ordered n stuff
How can HCM cause cardiac ischaemia?
Hypertrophic muscles are heavy massive so compress the coronary arteries
Reduces blood flow to areas leading to ischaemia
This is why HCM is a cause of stable angina and ACS’s
Apart from ischaemia, what other effects can HCM have on the heart?
Fibrosis
Arrhythmias
What are the symptoms of HCM
Asymptomatic for many
fatigue dyspnoea anginal like chest pain Palpations exertional pre syncope syncope related to arrhythmias or LV outflow tract obstruction
What are the main examination findings for HCM
Can be none
Notched pulse pattern
Irreg pulse if in AF or ectopy
Double impulse over apex, thrills and murmurs, often dynamic, LVOT murmur will increase with valsalve and decrease with squatting
JVP can be raised in very restrictive filling
How do you assess HCM?
ECG
ECHO
CMRI
Might do an ETT
Could do a Holter monitor (ECG)
Risk stratification for SCD, may need ICD
Will an ECG always show signs of HCM?
Usually yes
a few are normal where phenotype is poorly expressed in genotype +ve individuals
How is HCM managed pharmacologically?
if symptomatic - beta blockers, verapamil, disopyrimide
If in AF - anticoagulate
What general measures are taken to manage HCM?
Avoid heavy exercise
Avoid dehydration
Explore Family History and first degree relatives, ECGs and echo’s may be required
Consider genetic testing
Regular Follow Ups to re appraise the risks and progress
What surgical options can be used to manage HCM?
If the disease is obstructive; surgical or alcohol septal ablation
ICD if required based on risk stratification
Myocarditis is most commonly caused by what group of microorganisms?
Viruses
Describe the pathologyphysiology stuff for myocarditis
Infection causes infiltration of inflammatory cells into the myocardium
Inflammation reduces cardiac function leading to Heart failure
If conduction system is involved, then heart block and potential arrhythmias
Myocyte degeneration or necrosis is key histological feature
How would a patient with myocarditis typically present?
Fairly rapid onset of:
Heart failure;
fatigue
SOB
Chest pain
Fever
Signs of Heart failure (ankle oedema, lung crackles etc)
What investigations are carried out for myocarditis?
ECG
Biomarkers (bloods)
ECHO
CMRI
Tests for specific viruses
Why is a blood test useful for myocarditis?
Biomarkers such as cTn, CK often elevated but not falling in a pattern consistent with MI
Why is an ECHO useful for myocarditis investigation?
Can identify Regional wall motion abnormalities (RWMA)
What specific viral tests can be done for myocarditis?
Viral DNA PCR Auto antibodies Step antibodies Lyme B burgdorferi HIV
What are the general measures for treating myocarditis?
Supportive treatment of heart failure
Support for brady and tachy arrhythmias.
Immunotherpay if biopsy or other Ix point to a specific diagnosis
Stop possible drugs or toxic agent exposure
What is the prognosis for myocarditis?
30% recovery fully
20% mortality at 1 year
56% mortality by 4 years
At 11 years those still alive are 93% transplant free
What is pericarditis?
Inflammation of the pericardial layers with or without myocardial involvement
What are the main/key causes of pericarditis?
Idiopathic Viral Bacterial Post MI Perforation Dissection of proximal aorta Neoplasia
What are the symptoms of pericarditis?
chest pain with pleuritic features
sitting forward usually improves it lying back makes it worse
Fever
What are the signs of pericarditis?
Pyrexia
Low Blood pressure
Muffled heart sounds
Pericardial rub at LSE
Raised JVP
What does pericarditis with a raised JVP indicate?
raised JVP should make you consider not just pericarditis but effusion
If a patient has a high fever, is generally very unwell, but has no effusion
What does this indicate?
Likely bacterial pericarditis
What are the investigations for pericarditis?
ECG
Echo
Bloods (troponin)
Why should bloods be taken for a patient for pericarditis?
Raised cTn indicates myocardium is involved / infected as well
How would you identify pericarditis on an ECG?
PR depression & ST elevation
What are the general measures for pericarditis?
Viral is conservative
Idiopathic gets colchicine and limited use of NSAIDs
Bacterial must be drained even if small effusion and antimicrobials, high death rate
If large effusion present and some haemodynamic effects then drain
What is the risk posed by pericardial effusion?
Tamponade
What are the symptoms of Tamponade?
Symptoms are overt
fatigue
SOB
Dizzy with low BP
Occasionally chest pain.
What are the signs of Tamponade?
Signs are overt as well;
pulsus paradoxus JVP raised low BP \+/- rub \+/- muffled Heart Sounds
Pulmoary oedema although this is very rare in pericardial effusions/tampaonade
What investigations should be done for pericardial effusions or tamponade?
Urgent ECHO
CXR - can show large cardiac shadow
ECG
How is pericardial effusion or tamponade treated?
Drainage is the destination treatment
Persistent effusion needs a surgical pericardial window made to allow flow to abdomen
Send for MCS, neoplasic cells, protein and LDH
What is the nature of most pericardial effusions?
Exudate
Determined by sending sample for protein levels, LDH etc to be tested
What feature of an ECG would indicate a large pericardial effusion?
Electrical alternans
Axis of QRS alternates between beats ± wandering base line
Constrictive pericarditis is a rare type of pericarditis
What are the causes of it?
idiopathic radiation post surgery autoimmune renal failure sarcoid
What is the effect of constrictive pericarditis?
impaired filling although myocardium is normal most of the time
causes Diastolic heart failure
What are the symptoms of restrictive pericarditis?
fatigue, SOB, cough
What are the signs of restrictive pericarditis?
Right heart failure signs:
oedema ascites high JVP jaundice hepatomegally AFib Tricuspid regurgitation pleural effusion pericardial knock
How do you investigate restrictive pericarditis?
What disease must you make sure to differentiate against?
Echo
Right heart catheter
differentiate from restrictive cardiomyopathy which can be very difficult
How is restrictive pericarditis treated?
Careful and limited diuretics
Pericardectomy - removal of part/all of the pericardium
