HF, constrictive pericarditis, cardiomyopathy, myocarditis Flashcards
Define cardiomyopathy
A group of diseases in which the myocardium becomes structurally and functionally abnormal
…in the ABSENCE of coronary artery disease, valvular disease and congenital heart disease
What are the 3 layers of the heart?
epicardium = outer protective myocardium = muscular endocardium = thin inner layer
Primary versus secondary cardiomyopathy
1 = abnormality confined to the myocardium 2 = myopathy is part of a systemic disease
What are the 3 types of cardiomyopathy?
DILATED – ventricle dilated, thin walls, reduced ventricular pressure
HYPERTROPHIC – muscle hypertrophies inwards, more rigid, obstruction etc.
RESTRICTIVE – basically the same amount of muscle but it’s rigid and doesn’t pump as well as normal
Symptoms of cardiomyopathy
Symptoms of HF:
- SOB on exertion
- Fainting
- Fatigue
Sudden death often 1st presentation
Family history (sudden, unexplained death at young age)
Signs of cardiomyopathy
Signs of HF:
- Respiratory crackles
- Murmurs
- S3 = Early ventricular filling- due to ventricular dilation (dilated CM)
- S4 = Atrial contraction- due to stiff, low compliant ventricle (hypertrophic CM)
What investigations are done for cardiomyopathy?
GOLD STANDARD = ECHO
- visualise the structure, observe ventricular function
No single diagnostic test for all types:
- BNP
- CXR
- ECG
- cardiac catheterisation
- stress test
Which law applies to the pathophysiology of dilated cardiomyopathy?
law of Laplace: increased radius leads to reduced ventricular pressure
Ventricles enlarge and become dilated.
Walls thin and weaken -> can’t contract effectively
RF for dilated cardiomyopathy
ALCOHOL
post-viral (myocarditis from viral infection can damage)
haemochromatosis
genetic
Signs of dilated cardiomyopathy
DISPLACED APEX BEAT
Signs and symptoms of HF
TR/MR murmur- end diastolic
S3- due to rapid ventricular filling
On echo and x-ray, what findings would indicate dilated cardiomyopathy?
echo = dilated ventricle xray = globular, enlarged heart
State 3 ways in which hypertrophic cardiomyopathy can cause problems
- Increased stiffness/rigidity of the muscle affects pumping.
- Thickened muscle disrupts electrical conduction and causes arrhythmia.
- Hypertrophic Obstructive Cardiomyopathy (HOCM) = thickened ventricle obstructs cardiac outflow
RF for hypertrophic cardiomyopathy
50% is familial (autosomal dominant)
How does hypertrophic cardiomyopathy present?
Usually ASYMPTOMATIC
Sudden cardiac death is often the 1st presentation
Angina, dyspnoea on exertion, palpitations, syncope
Signs of hypertrophic cardiomyopathy
EJECTION SYSTOLIC MURMUR- dilated ventricles obstruct outflow
Jerky carotid pulse
Double apex beat but NOT DISPLACED ! (muscle grows inwards)
S4- due to ventricle non-compliance
How do heart sounds differ in dilated versus hypertrophic cardiomyopathy?
DILATED = S3 (Ken-tuc-ky)
- during passive ventricular filling (early disatolic)
- due to very compliant LV (ventricle wall vibration)
HYPERTROPHIC = S4 (Ten-es-see)
- during active ventricular filling (late diastolic)
- due to non-complaint LV (forceful atrial contraction)
State 2 signs of LVH on ECG
V1 + V2 = deep S
V5 + V6 = tall R (>7 large squares)
Signs of hypertrophic cardiomyopathy on ECG
Q waves
Left axis deviation
signs of LVH: deep S (V1/2) and tall R (V5/6)
Explain the pathophysiology of restrictive cardiomyopathy
- Ventricles become abnormally rigid and lose flexibility.
- Impaired ventricular filling during diastole.
- Reduced preload -> reduced CO + backing up of blood
Causes of restrictive cardiomyopathy
INFILTRATIVE -OSIS DISEASES:
sarcoidosis
amyloidosis
haemochromatosis
Familial
Idiopathic
Signs and symptoms of restrictive cardiomyopathy
usually ASYMPTOMATIC
signs of RIGHT HEART FAILURE:
- raised JVP
- S3
- ascites and oedema
- hepatomegaly
- Kussmaul’s sign = paradoxical rise in JVP during inspiration
What is Kussmaul’s sign and what does it indicate?
Kussmaul’s sign = paradoxical rise in JVP during inspiration
Indicates impaired right ventricular filling so blood backs up into the jugular vein.
What normally happens to JVP during inspiration?
Normally JVP falls with inspiration
due to reduced pressure in the expandingthoracic cavity
therefore increased volume afforded to right ventricular expansion during diastole.
Define constrictive pericarditis
Chronic inflammation of the pericardium with thickening and scarring
(basically chronic pericarditis with fibrosis)
Causes of constrictive pericarditis
Infectious (TB, bacterial, viral)- TB commonest cause worldwide
Acute pericarditis
Cardiac surgery and radiation- commonest in UK
Idiopathic
signs of constrictive pericarditis
Similar to restrictive cardiomyopathy
signs of RIGHT HEART FAILURE:
- raised JVP
- S3
- ascites and oedema
- hepatomegaly
- Kussmaul’s sign = paradoxical rise in JVP during inspiration
investigations for constrictive pericarditis
CXR: pericardial calcification
Echo: increased pericardial thickness – differentiate from restrictive cardiomyopathy
Cardiac CT/MRI
How can constrictive pericarditis be cured?
Surgical pericardial resection is the definitive treatment (pericardectomy)
(unlike restrictive CM which requires transplant)
Aston was a 33-year-old male who suddenly collapsed on stage. Although the doctors attempted “love CPR”, the patient died, and the post-mortem revealed a hypertrophic heart.
What was the most likely cause of death?
A. Obstructed flow of blood from the heart
B. Arrhythmia
C. Reduced pumping of blood due to stiff myocardium
D. Stroke
E. Sub-arachnoid haemorrhage
A. Obstructed flow of blood from the heart
Likely to experience warning symptoms beforehand
B. Arrhythmia
Most likely cause of death from HCM, hypertrophic muscle affects electrical circuits
C. Reduced pumping of blood due to stiff myocardium
Likely to experience warning symptoms beforehand
D. Stroke
Heart issue rather than brain issue, ventricular arrhythmia (not AF)
E. Sub-arachnoid haemorrhage
Heart issue rather than brain issue
Marvin presents with a 4-month history of increasing breathlessness and ankle swelling. On examination, he has ascites and Kussmaul’s sign is elicited.
What would be the most useful diagnostic investigation?
A. Echocardiography B. ECG C. Endomyocardial biopsy D. Abdominal X-ray E. CK
A. Echocardiography
Allows differentiation between restrictive cardiomyopathy and constrictive pericarditis
B. ECG
Non-specific signs – not the most useful
C. Endomyocardial biopsy
Pericardial biopsy might be useful – but highly invasive
D. Abdominal X-ray
Chest X-ray would be useful to look for pericardial calcifications, but these are not specific to constrictive pericarditis
E. CK
May be mildly elevated in both constrictive pericarditis and restrictive cardiomyopathy – not that helpful
Define myocarditis
Inflammation of the myocardium
i.e. Inflammatory cardiomyopathy
Causes of myocarditis
- Infectious- Coxakie B virus = most common cause in - Europe
- Drugs (cocaine)
- Metals
- Radiation
Signs and symptoms of myocarditis
Flu-like prodrome
Chest pain (worse when lying down)
SOB
Palpitations
Investigations myocarditis
ECG: non-specific ST and T wave changes
Cardiac biomarkers: CK and troponin
Endomyocardial biopsy: diagnostic but not routinely performed
What is the most common complication of myocarditis?
dilated cardiomyopathy (why dilated cardiomyopathy can be post-viral)
How can you differentiate between constrictive pericarditis and my myocarditis?
Cardiac biomarkers are not elevated in constrictive pericarditis, but they are in myocarditis because the muscle is affected
