Pathology of the cardiovascular system Flashcards
What is Atherosclerosis?
Calcified plaques in the intima of large and medium sized arteries
* They begin as fatty streaks, some of which progress to plaques
* Plaques can progressively enlarge causing stenosis and ischemia
* They can rupture causing a thrombus formation, total occlusion and critical ischemia
* Can put pressure on the underlying media causing an aneurysm
* Risk factors
o Increasing age
o Hypertension
o Smoking
o Diabetes
o Family history
o Alcohol
o Obesity
o
o Conditions it can cause include
§ Ischemia / infarction – MI, angina, cardiac failure, TIA, stroke, peripheral vascular disease
§ Aneurysmal dilation- thoracic or abdominal aortic aneurysm
What is heart failure? description, causes, symptoms
Description
o Describes cardiac ventricular dysfunction – the heart cannot pump enough blood around the body to
meet the body’s blood flow requirements. Used to be called congestive heart failure
- Causes
o Most common in older patients
o Coronary heart disease
o High blood pressure
o Cardiomyopathy
o Arrhythmias, such as atrial fibrillation
o Damage to the heart valves
o Congenital heart disease
o Lifestyle factors – obesity, anaemia, excess alcohol, pulmonary hypertension - Symptoms
o Breathlessness at rest or after activity
o Exhaustion most of the time
o Fainting / feeling lightheaded
o Swollen ankles and legs
Heart failure: diagnosis, complications, treatment, and differential diagnosis
Diagnosis
o Blood tests to check for damage (peptides signal stress on the heart, CRP indicates inflammation, BNP to diagnose
heart failure)
o ECG and / or echocardiogram
o Spirometry
o CXR - only about 70% accuracy. But may see pulmonary venous congestion, cardiomegaly, pulmonary oedema, pleural
effusions.
o US is the most common imaging used – transthoracic echocardiography. It can assess the appearance and function of
the ventricles, assess the valve anatomy and function and look at the pericardial space
o Cardiac CT can provide estimates of cardiac function and visualisation of cardiac structures
o Cardiac MRI can prvide highly accurate ejection fractions, identify abnormalities and is considered the gold standard
imaging modality.
o Complications
o Prognosis is poor – up to 70% of patients die within 5 years.
o Acute pulmonary oedema
o Arrhythmias such as ventricular tachycardia (can lead to VF and death)
o Treatment
o Make healthy lifestyle changes
o surgical management
§ Implantable ICD or PPM, cardiac transplant
o Treatment of complications
o Medication – betablockers most commonly
o Differential diagnosis
o Pneumonia
o PE
o Asthma
Potential areas for trans thoracic echocardiogram blind spots:
Pericardium
Aorta
left ventricular apex
cardiac valves
left atrial appendage
coronary arteries
extracardiac structures
What is Pericardial effusion?
Description
o Occurs when excess fluid collects in the pericardial space (normally 30-50ml)
- Causes
o Many! Including pericarditis (inflammation of the pericardium due to injury or disease), MI, RA, metastasis, particularly lung and
breast. - Symptoms
o Presentation relates to the speed fluid has accumulated. Patients will have impaired cardiac function, due to the pressure.
o Symptoms can include dyspnoea, reduced exercise tolerance. - Diagnosis
o CXR – need at least 200ml of fluid to see on a CXR. But may see heart enlargement (looks like a water bottle), pulmonary oede
o Echo – method of choice as you can measure the amount of fluid and assess the impact on cardiac function
o CT/ MRI – pericardium thickness of more than 4mm is considered abnormal - Complications
o Can lead to cardiac tamponade and death. - Treatment
o Small amount of fluid is usually managed conservatively
o Large amount – can be drained - Differential diagnosis
o Cardiomegaly of another cause
What is Mitral valve regurgitation?
Description
o Condition where the mitral valve leaks during systole (pumps blood into arteries) and so blood flows in the wrong direction from the
left ventricle into the left atrium
- Causes
o Chronic - Increasing age, congenital heart defects, calcium buildup preventing the valve from correctly functioning, cardiomyopathy
o Acute – MI, trauma - Symptoms
o Acute – severe symptoms of heart failure, shock
o Chronic – heart murmur on examination, dyspnoea, arrhythmia or palpitations - Diagnosis
o CXR – signs of left atrial enlargement (splaying of the carina, loss of the left atrial appendage), features of heart failure, pulmonary
oedema
o Echo – useful for assessing the cause and reviewing the left ventricle
o CT / MRI – not commonly used but may have some uses in assessing the underlying cause - Complications
o Heart failure, pulmonary hypertension, AF, sudden cardiac death. - Treatment
o Acute – mitral valve replacement
o Chronic – Drugs such as ACE inhibitors, anticoagulation. - Differential diagnosis
o Any causes of an enlarged heart and heart failure
What is Coronary artery disease?
Description
o This mainly refers to the narrowing of the coronary arteries due to atherosclerosis (calcification). This results in
myocardial ischaemia and globally is the leading cause of death
- Causes
o Atheroschlerosis. - Symptoms
o May be asymptommatic but include chest pain and angina symptoms - Diagnosis
o Coronary angiography and CTCA both look for luminal narrowing. - Complications
o MI due to complete artery occlusion
o Heart failure - Treatment
o Drugs to vasodilate and reduce blood pressure. Anticoagulation.
o Stents
o Coronary artery bypass grafts - Differential diagnosis
o Pericardial effusion, pneumonia, aortic dissection etc
What is Coronary artery bypass graft (CABG)?
Surgical procedure to increase blood flow to the
myocardium due to coronary artery stenosis
* Both arteries and veins can be grafted, often from the
patient’s leg or arm.
* Often grafted onto the left internal thoracic artery.
* Post CABG patients can develop
o Pleural or pericardial effusions
o PE
o Infection
What is Atrial fibrillation?
Description
o Is a supraventricular tachycardia with uncoordinated atrial electrical activation, and ineffectual atrial
contraction leading to an irregular and often abnormally rapid ventricular rhythm – an arrhythmia)
Atrial fibrillation (AFib) is an irregular and often rapid heart rhythm caused by disorganized electrical signals in the upper chambers of the heart (atria). (Arrhythmia)
- Causes
o Hypertension, ischaemic heart disease, heart failure, valvular heart disease, lifestyle - Symptoms
o Often asymptomatic
o May have an irregular pulse, dyspnoea, chest pain, dizziness, syncope (fainting). - Diagnosis
o ECG, identifying the underlying cause. - Complications
o Stroke, heart failure, increased all cause mortality. - Treatment
o Anticoagulation for stroke prevention, drug treatments for rate control, cardioversion, PPM
What is Abdominal aortic aneurysm?
Description
o Also called a AAA
o Focal dilatation of the abdominal aorta > 3cm in diameter
- Causes
o Increasing age, males more affected. - Symptoms
o Most are asymptomatic until they rupture so often an incidental finding.
o Patients may have pain or a pulsatile mass - Complications
o Rupture – 70% mortality before surgery - Treatment
o Generally, surveillance for less than 5cm and surgery for >5cm.
o May have an EVAR procedure - Differential diagnosis
o Aortic dissection
CT: Abdominal aortic aneurysm
Gold standard for
evaluation, but high
radiation dose
* Best for preoperative
planning as can relate
aneurysm to branch
arteries and the aortic
bifurcation
* If ruptured may see a
retroperitoneal blood clot
US: Abdominal aortic aneurysm
Best for screening and surveillance due to speed and no
radiation dose
* Sensitivity and specificity of nearly 100%
* But can be affected by patient body habitus or overlying
bowel gas
* Cannot plan surgery from US alone
What is EVAR?
Endovascular aneurysm repair
* For both elective and
emergency repair
* Inserted via the common
femoral artery.
* Complications include endoleak,
stent migration, infection
* Patients need lifelong
monitoring to monitor the graft
and check for complications
Atherosclerosis in the lower limbs /
peripheral arterial disease
Description
o Plaques causing stenosis in the arteries of the legs.
- Causes
o Risk factors include
§ Diabetes, smoking, advancing age, hypertension, obesity - Symptoms
o Leg pain when walking, cramping in the thigh or calf, weakness or pins and needles in the lower legs or feet, coldness
in the feet, weak pulse in the feet - Diagnosis
o On plain film you may see atherosclerotic plaques in the vessels
o US – can evaluate the arterial wall. US will see calcification as hyperechoic foci and when large, acoustic shadowing.
o CTA – uses contrast to look for luminal narrowing - Complications
o Severe pain, critical limb ischaemia, death of tissue due to infection, amputation due to gangrene - Treatment
o Lifestyle changes
o Angioplasty or bypass graft - Differential diagnosis
o Gout, arthritis
What is Stroke -
Ischaemic?
Description
o A stroke is a sudden onset of focal neurological deficit of
presumed vascular origin
o An ischaemic stroke (87%), is due to infarction in the central
nervous system. There is interruption of blood flow
through an intercranial artery leading to deprivation of
oxygen. If circulation is not re-established there will be
cell death.
- Causes
o Artheroschlerotic, tumour, thrombus, hupertension - Symptoms
o Paralysis or numbness of face, confusion and difficulty speaking, headache, vision
problems, unilateral weakness - Complications
o Can haemorrhage, can have complications such as aspiration pneumonia and PE.
Seizures, - Treatment
o Need to have fast treatment to encourage reperfusion
o Thrombolysis, clot retrieval - Differential diagnosis
o Ischaemic versus haemorrhagic
Stroke – ischemic - CT diagnosis
In ischemic stroke patients often have 3 scans
o Non contrast CT brain – ischemic or hemorrhagic
o CT perfusion – functional scan
o CT angiography – identify the location of a clot / narrowing
o CT is the most often used primary imaging method. It is quick, inexpensive and
available
o But is limited in the acute phase – may not show changes in the deep grey matter in
the early phase
o Aim of CT in the acute phase are to
§ Exclude hemorrhage, which would preclude thrombolysis
§ Look for any signs of ischemia
§ Exclude other causes like a tumour
§
o Earliest CT sign is a hyperdense vessel sign – representing the clot
o As time progresses and changes become chronic you will see low density.
Stroke – ischemic - MRI diagnosis
More time consuming but
has a higher sensitivity
and specificity for
diagnosing ischemic
infarction in the initial
stages
* Impact of early MRI in isch emic strokes beyond hype r-acute stage to improve p atient outcomes, enable e arly discharge, and realize cost savings - Journal of S troke and Cerebrovascular
Diseases
What is Stroke - hemorrhagic?
Description
o Is a type of intracranial haemorrhage, defined by accumulation of blood in the brain parenchyma (functional tissue).
Happens when there is a rupture of a small blood vessel.
- Causes
o Can be spontaneous or can be from an ischemic stroke, a vascular malformation, a tumour or metasteses - Symptoms
o Similar to those of an ischemic stroke. Patient is more likely to have decreased consciousness. May also have
headache, nausea and vomiting and seizures - Complications
o Seizures, swelling of the brain, memory loss, vision and hearing problems, death - Treatment
o Management is time critical.
o Blood pressure needs to be controlled, management of any raised intercranial pressure (drain), surgery to evacuate the
blood, management of seizures - intubation - Differential diagnosis
o Ischemic stroke
Stroke – hemorrhagic - CT diagnosis
Usually the first modality
used
* Imaging findings
o Hyperdense blood, often
with surrounding
edema
o May also see midline
shift, hydrocephalus
(increase in CSF and
enlarged ventricles)
Stroke – hemorrhagic - MRI diagnosis
Findings depend on the
size and age of the blood
* Can also show causes –
small vessels1
What is Subarachnoid Haemorrhage?
Also called a SAH
* Description
o Is a type of intracranial hemorrhage with
blood in the subarachnoid space
- Causes
o There are 2 causes
§ Trauma
§ Spontaneous – which can be due to a
ruptured aneurysm, various malformations
(AVM, SAM), anticoagulation therapy
o Risk factors include:
o Patients tend to be older middle age, often
less than 60
o Family history
o Hypertension
o Heavy alcohol comsumption
o Abnormal connective tissue
Symptoms
o Thunderclap headache
o Collapse and loss of consciousness
- Complications
o Elevated intracranial pressure – may require a drain
o Ischaemia (may require balloon angioplasty)
o Neurogenic pulmonary oedema
o PEA (no measurable cardiac output at cardiac arrest – non shockable rhythm) - Treatment
o Varies depending on the underlying cause - Differential diagnosis
o Meningitis
o Post thrombectomy iodine extravasation
Subarachnoid hemorrhage - CT diagnosis
CT normally performed first due to
availability
* Will see hyperdense material in the
subarachnoid space – most commonly
around the circle of Willis
Subarachnoid hemorrhage - MRI disgnosis
MRI is more sensitive than CT
at both identifying
hemorrhage and diagnosing
the underlying cause
* BUT – poor availability, longer
scan, greater difficulty with
unstable and ventilated
patients
* Will see blood as a
hyperintensity in the
subarachnoid space on FLAIR
What lines and tubes, wires and metal bits
are important
Central line
o Hickman line
o PICC line
o Port-a-cath
* Pacemaker
* Implantable defibrillator
* Cardiac monitoring device
* Sternotomy wires
* Replacement heart valves – TAVI, mitral.
What are Central lines?
Central venous catheter / central venous line /
CVC
* Generally seen in ED / ITU / theatre
* Refers to a catheter that is inserted so the
distal tip lies in the central vein
* They are usually inserted because
o the drugs given would be dangerous if they
extravisate or would irritate the venous system
o Difficult peripheral access
o Measurement of cardiac output / central venous
pressures
- There are 4 main categories
o PICC – peripherally inserted central catheters
o Non tunneled CVC’s e.g. short term in ITU or ED
– Vascath
o Tunneled CVC’s – e.g. Hickman
o Implantable ports (may be located in the chest
or arm) – e.g. port-a-cath - They can be inserted into many veins, the most
common are
o Internal jugular
o Subclavian
o Femoral (short term only)
o Brachial or cephalic (PICCS and implantable ports) - The tip should be in the superior vena cava or at
the cavo-atrial junction - Positioning – the SVC begins behind the lower
border of the 1st right costal cartilage and
descends vertically to drain into the right
atrium at the cavo-atrial junction.
The cavo-atrial junction is seen on a CXR:
o 2 vertebral bodies below the level of the carina
o Within 1 vertebral space either side of T5/6
What are PICC lines?
Peripherally inserted central
catheters
* Mainly used in oncology patients
and chronic diseases e.g. cystic
fibrosis
* Can have long term central venous
access without a tunneled port
* Performed under local anesthetic.
* Normally accessed through the
brachial veins
* Often done in theatre or in
fluroscopy
What is Vascath?
Generally used for dialysis
* Larger diameter than
most CVC’s
What is a Hickman catheter?
Tunneled line
* Typically inserted into the
jugular vein and the
proximal tubing is
tunneled through the
subcutaneous tissue to a
skin incision on the chest.
* Used commonly for
chemotherapy drugs,
parenteral nutrition and
long-term antibiotics
What Is a Port-a-cath (implantable port)?
Used for patients requiring long term
venous access
* They can last for years (PICC last for
weeks or months)
* They require less upkeep (PICC
require daily flushing)
* They are waterproof
* Useful for patients who
o Need long term IV medicine –
commonly chemotherapy or
antibiotics
o Peripheral access where cannulation
is difficult
o To withdraw blood on a regular basis
Pacemaker
Inserted to improve patient
outcome by cardiac pacing.
* This includes
o stimulating a faster heart rate when
the heart is beating too slowly
(Bradycardia causing syncope)
o Maintaining a suitable heart rate and
rhythm – e.g. patients in AF
o In patients with heart block – pulse
sent from SA node to AV is delayed
or absent
o It can reduce symptoms of heart
failure such as breathing problems
and lower limb oedema.
o It can prevent syncope
o Most pacemakers are demand
pacemakers so only pace on
demand
They can be temporary – usually done in an acute setting
to support a patient with bradycardia until the cause is
reversed or a permanent pacemaker is inserted
* A permanent pacemaker (PPM) can be the following types
o Single chamber pacemaker
1 wire which is connected to the right atrium or right ventricle
o Duel chamber pacemaker
2 wires which are connected to the right atrium and right ventricle
o Biventricular pacemaker
1 wire which is connected to the right atrium or right ventricle
* 3 wires connected to the right atrium, right ventricle and left ventricle
Pacemaker insertion
Inserted under local anaesthetic in the subclavian
region on the left or right side (to avoid the dominant
side)
* Leads are placed via the cephalic or subclavian vein
* The right atrial lead is passed into the right atrial
appendage
* The right ventricular lead is passed to the right
ventricular apex
* The left ventricular pacing leads are placed in the
coronary sinus veins
* Leads are tested before they are connected to the
generator.
Appearances on a CXR
Duel lead
o Atrial lead in the right atrial
appendage usually pointing
cranially
o Right ventricular lead is in
the RV apex pointing up
towards the upper heart
border
o On a lateral image both
leads should point
anteriorly
Single lead
* Lead sits within the right atrium or
the right ventricle depending on the
clinical presentation
Complications of a PPM
Lead fracture
AICD / ICD’s
Automatic implantable cardioverter
defibrillators
* Device recognises ventricular tachycardia
and fibrillation and terminates it by
delivering an electrical shock
* They are generally implanted in patients
with cardiomyopathy who are at risk of
VT,VF and sudden cardiac death
* The thicker bit at the end of the lead is
the shock coil
* Also useful in patient monitoring of VF
and VT.
* You will often find both an ICD and a PPM
used to treat the arrthymia and act as a
fail safe system.
Implantable loop recorder
Small device that sits
under the skin for
cardiac monitoring
* Continuously performs
ECG’s and stores any
arrhythmias for review.
* Can be activated by
abnormal heart rhythm
or by the patient
manually
Sternotomy wires
Sternotomy wires are
stainless steel wires used to
hold the sternum together
after heart surgery and a
median sternotomy
* Needed to maintain the
stability of the sternum
during respiration
* Can be single wires or a
figure of 8 layout
Heart valve replacement
All 4 heart valves can be surgically replaced.
* Most common are the aortic and mitral valves
* They are sometimes replaced via a catheter from a
femoral artery approach called a TAVI
