Cardiology: Cardiomyopathy + Aortic Dissection Flashcards by Isabelle Schiff

What is cardiomyopathy?

Structural and functional abnormality of the myocardium without CAD, HTN, valvular or congenital heart diseases

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What are the four main types of cardiomyopathy?

1) Dilated
2) Hypertrophic (HOCM)
3) Restrictive
4) Arrhythmogenic right ventricular cardiomyopathy

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What is the most common type of cardiomyopathy?

Dilated cardiomyopathy

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When do most patients present with dilated cardiomyopathy?

Between age 20-60

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What are the causes of dilated cardiomyopathy?

1) Ischaemic changes over time can manifest as dilated cardiomyopathy esp. post MI
2) Hypertension
3) Genetic and congenital - familial dilated cardiomyopathy, sporadic gene mutations in idiopathic
4) Toxin-related i.e. drugs
5) Infiltrative - haemochromatosis, amyloidosis, sarcoidosis
6) Peripartum (rare)
7) Thyrotoxicosis
8) Infectious
9) Stress-induced cardiomyopathy (Takotsubo cardiomyopathy)
10) Idiopathic - when other potential causes have been ruled out

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Which drugs can cause dilated cardiomyopathy?

1) Excessive alcohol consumption - leads to myocardial dysfunction and subsequent DCM
2) Cocaine - ischaemia and DCM
3) Anthracycline chemotherapy (doxorubicin)
4) Cyclophosphamide
5) Antiretroviral drugs (zidovudine)
6) Chloroquine
7) Clozapine

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What are infectious causes of dilated cardiomyopathy?

1) Secondary to myocarditis
2) Direct result of infection from HIV, Lyme disease and Chagas disease

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What is stress induced cardiomyopathy (Takotsubo cardiomyopathy)?

Transient left ventricular ballooning precipitated by intense psychologic stress - almost all patients recover completely

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What are the clinical features of dilated cardiomyopathy (see on echo)?

Dilation and poor contraction of the left ventricle or both ventricles (EF < 40%)

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What is the EF in dilated cardiomyopathy?

< 40% (of left or both ventricles, poor contraction + dilation)

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What are the symptoms of dilated cardiomyopathy?

Most common = heart failure symptoms:
1) Exertional dyspnoea
2) Orthopnoea
3) Paroxysmal nocturnal dyspnoea
4) Peripheral oedema
Consequences of cardiomyopathy:
5) Arrhythmia - AF or VT
6) Conduction disturbances
7) Sudden cardiac death

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Which arrhythmias can occur as a result of dilated cardiomyopathy?

AF or VT

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Symptoms and signs of which condition occur in dilated cardiomyopathy?

Heart failure

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What are the examination findings in dilated cardiomyopathy?

1) Displaced apex beat
2) S3 gallop rhythm (rapid ventricular filling)
3) Mitral regurgitation murmur (due to displacement of the valve leaflets)
4) Signs of heart failure - oedema, hepatomegaly, ascites, raised JVP

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Which two signs are heard on auscultation in dilated cardiomyopathy?

1) S3 gallop rhythm
2) Mitral regurgitation murmur

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What might you see on ECG in dilated cardiomyopathy?

Poor R wave progression

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What is the diagnostic investigation for dilated cardiomyopathy?

Echo

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What is hypertrophic cardiomyopathy (HCM)?

A genetic condition characterised by left ventricular hypertrophy of varying degrees

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What causes hypertrophic cardiomyopathy?

Mutation in one of several myocyte sarcomere genes e.g. myosin and troponin, causing myocyte hypertrophy and disarray

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Which gene is mutated in HCM?

One of several myocyte sarcomere genes e.g. myosin and troponin

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What is the inheritance of HCM?

Autosomal dominant

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What causes the genetic defect in HCM?

1) Autosomal dominant inheritance
2) 50% of cases due to sporadic mutations where the parents do not carry a disease-causing gene

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When does HCM develop?

1) Most of the hypertrophy develops during childhood and adolescence
2) Genetic variation means some late onset disease does not occur

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What are the consequences of HCM?

The abnormal morphology of the left ventricle can cause severe consequences:
1) Left ventricular outflow tract obstruction (LVOTO) - this is known as HOCM
2) Diastolic dysfunction
3) Ischaemia
4) Mitral regurgitation

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What are the symptoms of HCM?

1) Many patients have little to no symptoms and the initial presenting conditions can sometimes be presyncope, syncope or sudden death 2) Exertional dyspnoea 3) Fatigue 4) Chest pain (anginal or atypical)

What are the signs of HCM?

Typical findings: 1) Jerky pulse 2) Double apex beat 3) Harsh ejection systolic murmur 4) Apical thrill (physical examination can also be normal or non-specific)

What are the ECG findings in HCM?

1) Abnormal Q waves 2) Deeply inverted T waves 3) Left ventricular hypertrophy

How do you diagnose HCM?

Echo - shows an area of left ventricular wall thickness in the absence of any other cause

What is restrictive cardiomyopathy?

Non-dilated non-hypertrophied ventricles with impaired ventricular filling

What are inherited genetic causes of restrictive cardiomyopathy?

Familial non-infiltrative cardiomyopathy (inherited genetic disorders)

What are infiltrative causes of restrictive cardiomyopathy?

1) Amyloidosis 2) Sarcoidosis 3) Gaucher disease 4) Hurler syndrome 5) Fatty infiltration

What are storage causes of restrictive cardiomyopathy?

1) Haemochromatosis 2) Fabry disease 3) Glycogen storage disorders

What are other causes of restrictive cardiomyopathy?

1) Diabetic cardiomyopathy 2) Scleroderma 3) Hypereosinophilic syndrome (Löffler's) 4) Radiation 5) Chemotherapy (anthracyclines e.g. doxorubicin and daunorubicin)

How does restrictive cardiomyopathy present?

1) Often present as heart failure 2) Sometimes present similar to constrictive pericarditis 3) Up to 75% have associated AF

How do you diagnose restrictive cardiomyopathy?

1) Echo (shows thickened ventricular walls and valves) AND 2) Cardiac MRI (useful for distinguishing between restrictive cardiomyopathy and constrictive pericarditis)

What causes aortic dissection?

A tear in the tunica intima of the aorta creates a false lumen whereby blood can flow between the inner and outer layers of the walls of the aorta

What are risk factors for aortic dissection?

1) Hypertension 2) Connective tissue disease e.g. Marfan's syndrome 3) Valvular heart disease 4) Cocaine/amphetamine

What classification is used to classify aortic dissections?

Stanford classification

What is a Stanford Type A aortic dissection?

Involves the ascending aorta + arch of aorta

What is a Stanford Type B aortic dissection?

Involves the descending aorta

Which patients usually present with aortic dissection?

Men > 50

How does aortic dissection present?

1) Sudden onset tearing chest pain or interscapular pain radiating to the back 2) Depending on how far the dissection extends it can also present with bowel/limb ischaemia, renal failure and syncope

What are the examination findings in aortic dissection?

1) Radio-radial delay 2) Radio-femoral delay 3) Blood pressure differential between arms

What investigation is used to diagnose aortic dissection?

CT angiogram

What might you see on ECG in aortic dissection?

Ischaemia in specific territories if dissection extends into coronary arteries

What might you see on echo in aortic dissection?

Pericardial effusion + aortic valve involvement

What might you see on CXR in aortic dissection?

Widened mediastinum

What will blood tests show in aortic dissection?

1) Raised troponin 2) Raised D dimer

Why is prompt diagnosis and treatment of aortic dissection required?

Bc aortic rupture carries an 80% mortality rate

What is the initial management of aortic dissection?

1) Resuscitation 2) Cardiac monitoring 3) Strict BP control e.g. IV metoprolol infusion

Which medication is given in aortic dissection and why?

IV metoprolol infusion (strict BP control)

How is a Type A aortic dissection managed?

(Open) surgery e.g. aortic graft

How is a type B aortic dissection managed?

1) Normally managed conservatively with BP control 2) If evidence of end organ damage then endovascular or open repair may be performed

What are complications of aortic dissection?

1) Death due to internal haemorrhage 2) Rupture 3) End organ damage (renal or cardiac failure) 4) Cardiac tamponade 5) Stroke 6) Limb ischaemia 7) Mesenteric ischaemia

What causes cardiac tamponade?

1) Accumulation of fluid, blood, purulent exudate or air in the pericardial space raises the intra pericardial pressure 2) Subsequently, diastolic filling is reduced thereby reducing the cardiac output 3) It is a life threatening emergency that requires prompt diagnosis with echocardiogram and treatment

What does cardiac tamponade cause?

Reduced diastolic filling + cardiac output

What are the symptoms of cardiac tamponade?

1) SOB 2) Tachycardia 3) Confusion 4) Chest pain 5) Abdominal pain

What is the name for the set of signs of cardiac tamponade?

Beck's triad

What are the key signs of cardiac tamponade (Beck's triad)?

1) Hypotension 2) Quiet heart sounds 3) Raised JVP

What are the risk factors for cardiac tamponade?

1) Malignancy 2) Purulent pericarditis 3) Severe thoracic trauma 4) MI 5) TB

What are two additional signs seen in cardiac tamponade to Beck's triad?

1) Raised JVP on inspiration - Kussmaul's sign 2) Pulsus paradoxus - pulse fades on inspiration

What is the diagnostic test for cardiac tamponade?

Echo

What is Kussmaul's sign?

Raised JVP on inspiration

What is pulsus paradoxus?

Pulse fades on inspiration

What might you see on ECG in cardiac tamponade?

Low voltage QRS complexes or electrical alternans

What would you see on CXR in cardiac tamponade?

Large globular heart

What would you see on Echo in cardiac tamponade?

Shows amount of fluid around the heart and quantifies the level of ventricular compromise

What would you do after echo diagnosing pericarditis?

Pericardiocentesis - allows for sampling of the fluid to find the underlying cause + treats the immediate problem

What is the first line management for pericarditis in patients who are haemodynamically unstable?

Pericardiocentesis

What is the first line treatment in patients with haemopericardium, associated malignancy or traumatic/purulent effusion?

Surgical drainage

What are the complications of pericardiocentesis?

1) PTX 2) Damage to the myocardium or coronary vessels 3) Thrombus 4) Arrhythmias/cardiac arrest 5) Damage to the peritoneum

What should all patients have post pericardiocentesis and why?

CXR - to exclude PTX