Cardiomyopathy Flashcards
What is cardiomyopathy?
Heart muscle disease
What are the main types of cardiomyopathy?
Hypertrophic
Dilated
Restrictive
Myocarditis
What is dilated cardiomyopathy?
When all four chambers of the heart enlarge
What are the causes of dilated cardiomyopathy?
Primary: Idiopathic Genetic mutation Infection Inflammatory Alcohol Drugs Post partum Tropical disease Haemaochromatosis Sarcoid
Secondary to pathological insult to myocardium
How does dilation occur in DCM?
New sarcormere are added in series and chamber grow larger leaving the walls thin compared to large chamber size - therefore less muscle used for contraction
How does DCM lead to congestive heart failure?
Less contraction -> less SV -> biventricular congestive heart failure as heart cant pump blood out to lungs and body efficiently -> systolic HF
What are the symptoms of DCM?
Progressive dyspnoea Fatigue Orthopnoea Paroxysmal nocturnal dyspnoea (PND) Ankle swelling Weight gain (fluid overload) Cough
What should be looked for in the clinical history for DCM?
PMH:
Illness, HPT, vascular disease, thyroid, neuromuscular disease
SH:
Travel, alcohol, job
What are clinical signs of DCM?
Poor perfusion Thready pulse Elevated JVP Displaced apex S3 and S3 MR murmur Pulmonary, sacral and ankle oedema Pleural effusion Thready pulse Acites Hepatomegally
What are the conditions that DCM commonly presents with?
Heart failure Cardiac arrhythmias Conduction defects Thromboembolism Sudden death
How can DCM cause regurgitation of AV valves?
Dilation of chambers, stretches valve so that they cant close all of the way during systole
MR can produce holosystolic pressure and S3 sound due to blood slamming against ventricle wall during diastole
How can DCM cause arrhythmia?
Stretching of muscle wall can irritate myocytes important for conduction
What investigations should be carried out for DCM?
ECG CXR BNP level FBC U+E Echo CMRI Coronary angiogram Biopsy depending on type of type of cardiomyopathy
What are general measures to treat DCM?
Correct anaemia
Remove exacerbating factors i.e. drugs
Reduce Na intake
What are specific measures to treat DCM?
ACEi
ATII blockers
Diuretics
B blockers
Spionolactone
Anticoagulants as required (thrombus formation common in DCM)
What are surgical measures to treat DCM?
Cardiac transplant
Sudden cardiac death risk with defibrillator implant
What is restrictive cardiac myopathy?
Myocardium become stiffer and less compliant - which means less blood enters the ventricle during diastole as they ventricles do not stretch to allow more blood in
How does RCM cause heart failure?
Stiffer myocardium means ventricles don’t stretch during diastole -> less blood pumped out -> diastolic heart failure
What are the causes of RCM?
Amyloidosis, sarcoid Familial, forms of HCM, diabetic Haemachromatosis Fabry disease Fibrosis, carcinoid, radiation, drug effects
How do amyloid cause RCM?
Misfolding of proteins which make it insoluble and can deposit in tissue
How does sarcoids cause RCM?
Forms granulomas in myocardium
Why does bi-atrial dilation occur in RCM?
Less filling of ventricles means extra blood in atrium
How does haemachromatosis cause RCM?
Too much iron from the diet is absorbed and it builds up in the myocardium
What investigation should be carried out for RCM?
ECG CXR BNP FBC U+Es - sarcoid and haemachormatosis Auto-Antibodies for sclerotic (hardening) connect tissue diseases Cardiac biopsy - amyloid Fabry - low plasma galactosidase A activity Echo CMRI
How does radiation cause RCM?
radiation generate reactive oxygen species in the myocardium which causes inflammation -> myocardial fibrosis
What can an ECG show in RCM?
Smaller QRS complexes due to restricted ventricular contraction
What is fabry disease?
Genetic disease a deficiency of the enzyme alpha-galactosidase A (a-Gal A) that causes a buildup of a type of fat in tissue
What are general measure for RCM?
Limited diuretic use B blockers Anticoagulats SCD risk assessment with IC implant Cardiac transplant Treat iron overload if due to amyloid or sarcoid
What is hypertrophic cardiomyopathy?
When walls are thick, heavy and hypercontractile - new sarcomeres are added in parallel
Usually affect Left ventricle
How does HCM lead to heart failure?
Larger muscles take up more room so less blood fills into the ventricle
Myocardium stiff and less compliant so less blood fills ventricle due to reduced stretch
Less EDV -> decreased SV -> diastolic heart failure
What genetic inheritance is HCM?
Autosomal dominant
Describe the pathology of HCM?
Myocyte hypertrophy and disarray
Wall thickness > 14mm
Can be apical, septal or generalised
Septal hypertrophy can cause mitral valve effect and lead to LVOT obstruction
What is the Venturi effect?
Septal muscle growth can obstruct the LV outflow tract during systole
This increases blood velocity through the smaller opening which pulls the anterior leaflet of the mitral valve toward the septum - venturi effect
This further obstructs LVOT
What are the symptoms of HCM?
Asymptomatic Fatigue Dysnoea Chest pain - like angina Exertional pre-syncope Syncope related to arrhythmia or LVOT Palpitations SCD
What are the clinical signs of HCM?
Can be none
Notched pulse pattern
Irregular pulse if in AF or ectopy
Double impulse over apex, thrills and murmurs
LVOT murmur - will increase which Valsalva and decrease with squatting
JVP elevated in very restrictive filling
What investigations are used for HCM?
ECG
Echo
CMRI
Risk stratification for SCD, may need ICD
Why does squatting decrease LVOT murmur in HCM?
Systemic vascular resistance increases making it harder to eject blood and increases afterload
This increases ESV which stretches valves from septum so it is less obstructed, decreasing to LVOT murmur
Why does the valsvalva manouver increase the LVOT in HCM?
Decreases venous return -> decrease preload, so less blood to stretch out ventricle so obstruction is larger and murmur intensity increases
Why does the apex produces a double impulse?
Due to the mitral valve moving to the outflow tract causing increase in obstruction mid-systole
What are general measures for treatment of HCM?
No heavy exercise No dehydration FH and first degree relatives ECG Echo Genetic testing
Why does HCM lead to formation of arrhythmia?
Myocardium becomes ischaemic as cant pump effieicintly
Also why most common cause of sudden cardiac death
What is myocyte disarray?
Lack of striations in myocardium
What are specific measure to treat HCM?
Enhance relaxtion: B blocker, verapamil (CCB), disopyrimide
AF: anticoagulant
Surgical or alcohol septal ablation
ICD implant based on risk assessment
What is myocarditis?
Acute or chronic inflammation of the myocardium
This can impair myocardial function, conduction and generate arrhythmia
How does myocarditis lead to heart failure?
Myocardial inflammation causes swelling which damages myocyte needed to contract
This means less blood is pumped is pumped out of the heart during systole
What are two possible outcomes of myocarditis?
Inflammation resolves and heart contractility returns to normal
If severe, can causes fibrosis and scar tissue of myocardium -> long term problems with contraction
What are causes of myocarditis?
Viral infections - can trigger lymphocytic myocarditis where lymphocytes and water enter ISF space of myocytes : adenovirus
Bacterial: strep., mycobacterial
Lymes disease
What is the pathology of myocarditis?
Infiltration or inflammatory cells into the myocardial layers, reduced function and heart faikur, heat block as conduction system involve and arrythmias
What are the symptoms of myocarditis?
Arrhythmias Positional chest pain Fatigue Fever sob HF sign: peripheral oedema
What investigations should be carried out for myocarditis?
ECG Biomarkers elevated (troponin, creatine kinase) Echo CMRI Viral DNA PCR Auto antibodies Strep antibodies Lyme B burgdoferi HIV Biopsy can diagnose but it is risky
What can echo show in myocarditis?
Regional wall motion abnormalities (RWMA)
Inflamed heart muscle walls
What can CMRI show in myocarditis?
Oedema
Cardiomegaly
What can ECG show in myocarditis?
Sinus tachycardia
T wave inversion
What are general measure in treatment of myocarditis?
Virus is self limiting
Other infections - antibiotics
HF: meds and fluid balance
Arrhythmias: resolves as inflammation does
Immunotherapy if biopsy point to specific outcome
Cardiac transplant if severe
What is pericarditis?
Inflammation of the perIcardium
How does pericarditis lead to pericardial effusion?
Inflammation causes fluid to build up the the pericardial cavity, as the serous pericardium cannot remove the fluid as quickly as it comes in
What are the two layers to the pericardium?
Fibrous outer layer
Serous inner later (visceral, pericardial cavity, parietal)
What are the causes of pericarditis?
Idiopathic
Viral
Bacterial Post MI (dressler's syndrome) Perforation Dissection of aorta Neoplasia Autoimmne diseases: systemic lupus erythematosus Cancer and chest radiation
How does post MI lead to pericarditis?
Necrosis leads to inflammation that also involves serous pericardia
What is the pathology of pericarditis?
Pericardial inflammation means that fluid and immune cells move from the cavity through BV to the fibrous and serous pericardium
This enlarges the layers
What is the effect of a pericardial effusion?
Puts pressure on the heart, preventing it from fully stretching out or relaxing which can lead to tamponade
What is a tamponade?
Perical effusion putting pressure on heart so it doesn’t fill properly, causing decrease in CO which can be medical emergency
What is the pathophysiology of chronic pericarditis?
Immune cells initiate fibrosis of the serous pericardium, forming an inelastic shell around the heart, decreasing ventricular compliance -> decreases SV but HR increases to compensate
What are the symptoms of pericarditis?
Fever
Chest pain - pleuritic and postual features (sitting forward improves)
What are the signs of pericardial disease?
Pericardial rub
Raised JVP
Low BP
Muffled HS
What investigations should be carried out for pericarditis?
ECG
Echo
CXR
Troponin may be raised
What can an ECG show in pericarditis?
- ST elevation
PR depression - After few weeks - T wave inverts
- Returns to normal
Pericardial effusion:
Small QRS complex
What can a CXR show in pericarditis?
Large pericardial effusion - large shadow
What can an echo show in pericarditis?
Pleural cardial effusion - dancing heart
Chronic pericarditis - stiff pericardium restricting movement
What are measures to treat pericarditis?
Relieve pain
Treat cause
If severe effusion: pericardiocentesis (drains fluid)
What are symptoms of pericardial effusion?
Fatigue SOB Dizziness Low BP Occasionally chest pain
What are signs of pericardial effusion?
Pulsus paradoxus JVP raised Low BP Pericardial rub Muffled HS
What are key investigation for pericardial effusion?
Echo
CXR
ECG
What can an ECG show for pericardial effusion?
Electrical alternans:
QRS complexes have different heights due to the heart swinging back and forth in a pool of pericardial fluid
What are the causes for constrictive pericarditis?
Idiopathic Radiation Post surgery Autoimmune Renal failure Sarcoid
What are symptoms of constrictive pericarditis?
Fatigue
SOB
Cough
What are the signs of constrictive pericarditis?
RHF: Oedema Ascites High JVP Jaundice Hepatomegally AF Pleural effusion
What investigations should be carried out for constrictive pericarditis?
Echo
R heart catheter to differentiate from restrictive cardiomyopathy
What is the treatment for constrictive cardiomyopathy?
Limited diuretics
Pericardectomy
