cardio Flashcards
What is thrombosis?
Blood coagulation in a vessel
What is DVT?
deep vein thrombosis
The development of a blood clot within a vein deep to the muscular tissue planes
normally in a major deep vein in leg, thigh, pelvis, abdomen
Which factors does warfarin prevent synthesis of?
2
7
9
10
What scoring system is used in DVT?
Well’s diagnostic algorithm
What is an aneurysm?
a permanent and irreversible dilatation of a blood vessel by at least 50% of the normal expected diameter
What is the normal diameter of the abdominal aorta?
2cm
Increases with age
What is the threshold diameter of an AAA?
3cm
What are the different sizes of AAAs?
Normal: less than 3cm
Small aneurysm: 3 – 4.4cm
Medium aneurysm: 4.5 – 5.4cm
Large aneurysm: above 5.5cm
What is a pseudoaneurysm?
caused by blood leaking through the arterial wall but contained by the adventitia or surrounding perivascular tissue
What prophylaxis is offered to patients in hospital at higher risk of VTE?
Low molecular weight heparin
Compression stockings
What are contraindications to giving LMWH?
Active bleeding
Existing anticoagulation (warfarin, DOAC)
What is a contraindication to using compression stockings as prophylaxis for VTE?
Peripheral arterial disease
What is the epidemiology for VTE?
1 in 1000
2/3 of these are DVT, 1/3 PE
What is the aetiology of DVT and PE?
(and what model shows this?)
Virchow’s triad:
* Stasis: blood flows slowly or becomes turbulent, could be caused by immobility, long travel, varicose veins, obesity
* Hypercoagulability: blood coagulates quicker than normal, e.g. thrombophilia, oestrogen therapy, malignancy, infection and inflammation
* Endothelial injury: e.g. physical trauma, hypertension
What makes up Virchow’s triad?
- Stasis: blood flows slowly or becomes turbulent
- Hypercoagulability: blood coagulates quicker than normal
- Endothelial injury
What are the risk factors for DVT and PE?
Immobility
Recent surgery
Pregnancy
Long haul travel
Hormone therapy with oestrogen, combined pill or HRT
Polycythaemia
Malignancy, cancer
SLE
Thrombophilia: e.g. antiphospholipid syndrome
Is the D-dimer test specific for VTE?
No
It’s sensitive so most patients with DVT will have a positive d-dimer
But not all positive d-dimers mean a DVT
What are 2 anticoagulants used in the treatment or prophylaxis of VTE?
apixaban
rivaroxaban
prophylaxis after some surgeries
What is a PE?
dislodged thrombi occluding the pulmonary vasculature
What are the key presentations for DVT/PE?
Calf or leg swelling and pain
Chest pain
Breathlessness
Differential diagnoses for PE
Angina
MI
COPD/asthma acute exacerbation
Pneumothorax
Congestive heart failure
Differential diagnoses for DVT
Cellulitis
Calf muscle tear/Achilles’ tendon tear
Calf muscle haematoma
Large or ruptured popliteal cyst (Baker’s cyst)
Pelvic/thigh mass/tumour compressing venous outflow from the leg
What investigations would you carry out for suspected DVT?
D-dimer
Doppler (venous) ultrasound
What investigation would you run for suspected PE?
apart from d-dimer
CTPA
CT pulmonary angiogram
How would you manage DVT/PE?
Initial resus for PE if needed
Run tests (D-dimer must be done before starting anticoags to avoid false negative)
Start anti-coagulants immediately, even before results: apixaban or rivaroxaban, if not suitable offer LMWH
How long after a case of DVT/PE would a patient stay on anticoagulants?
3 months at least
What are some complications of DVT?
PE
Bleeding during initial treatment
Heparin induced thrombocytopenia (HIT)
What are some complications of PE?
Pulmonary infarction
Cardiac arrest
Death
What are some signs of DVT?
tenderness, swelling, warmth, discolouration
What are some signs of PE?
tachycardia, tachypnoea, pleural rub, hypoxia, pyrexia, elevated JVP
What are the symptoms of DVT?
Limb pain and tenderness
Swelling of the calf or thigh (usually unilateral).
Pitting oedema.
Distension of superficial veins.
Increase in skin temperature.
Skin discoloration
A hard, thickened palpable vein
What are the symptoms of PE?
Dyspnoea
Pleuritic chest pain, retrosternal chest pain.
Cough and haemoptysis.
Any chest symptoms in a patient with symptoms suggesting a deep vein thrombosis (DVT).
In severe cases, RHF causes dizziness or syncope
Why do you use a d-dimer test for DVT?
Acute thrombus begins to be dissolved by the body’s fibrinolytic system as soon as a clot begins to form
elevated levels of breakdown products of cross-linked fibrin (D-dimer) appear in the blood soon after a clot begins to form
What is ischaemic heart disease?
an inability to provide adequate blood supply to the myocardium
When is IHD considered stable?
when symptoms, if any, are manageable and not rapidly progressive
no recent infarction, procedural intervention, or signs of significant ongoing cardiac necrosis
symptoms only come on with exertion and are always relieved by rest or glyceryl trinitrate
What are some modifiable risk factors for hypertension?
Excess weight.
Excess dietary salt intake.
Lack of physical activity.
Excessive alcohol intake.
Stress
What is the white coat effect?
blood pressure is raised due to the stress of being in clinic
What are some non-modifiable risk factors for hypertension?
Older age
Family history
Ethnicity
Gender
What is stage 1 hypertension?
clinic BP 140/90 mm Hg
135/85 on home or ambulatory readings
What is stage 2 hypertension?
Above 160/100 in clinic
Above 150/95 on home/ambulatory readings
What is stage 3 hypertension?
Above 180/120
What investigations would you do for someone with hypertension?
ECG
fasting metabolic panel with estimated GFR
lipid panel
urinalysis
Hb
thyroid-stimulating hormone
How would you monitor hypertension?
While adjusting medication dosage, blood pressure (BP) should be monitored every 2-4 weeks.
Once stabilised, BP should be checked and medications reviewed every 6-12 months
What are some secondary causes of hypertension?
- Renal disease
- Pregnancy and pre-eclampsia
- Endocrine: Conn’s, thyroid disorders
- Drugs: NSAIDs, steroids, oestrogen, liquorice, alcohol
- Obesity
What is primary hypertension?
develops without secondary cause
90% of cases
What does hypertension increase the risk of?
- IHD (angina and acute coronary syndrome)
- Cerebrovascular accident (stroke or intracranial haemorrhage)
- Vascular disease
- Hypertensive retinopathy and nephropathy
- Vascular dementia
- Left ventricular hypertrophy
- Heart failure
What are some differentials for hypertension?
Renal artery stenosis
Chronic kidney disease
Obstructive uropathy
Obstructive sleep apnoea/hypopnoea syndrome
Obesity hypoventilation syndrome
What is heart failure (HF)?
a complex clinical syndrome resulting from the impaired ability of the heart to cope with the metabolic needs of the body
heart can’t meet perfusion needs
What is the LV ejection fraction in HF with reduced EF?
less than 40%
What is the LVEF in heart failure with mildly reduced EF?
41-49%
What is the LVEF in HF with preserved EF?
50% or more
What is HFrEF?
heart can’t pump with enough force to push enough blood into circulation
EF less than 40%
aka systolic HF
What is HFpEF?
heart can’t properly fill with blood during the resting period between each beat
EF 50% or more (stroke volume is low but so is EDV)
aka diastolic heart failure
What is the main cause of right sided HF?
Left sided HF
What is left sided heart failure?
the left side must work harder to pump the same amount of blood
HFrEF: left ventricle loses its ability to contract normally
HFpEF: Left ventricle loses its ability to relax normally because the muscle has become stiff
Equation for cardiac output
Heart rate (HR) x Stroke volume (SV)
What happens in right sided heart failure?
When the left ventricle fails and can’t pump enough blood out, increased fluid pressure is transferred back through the lungs.
This damages the heart’s right side. When the right side loses pumping power, blood backs up in the body’s veins
What are specific signs for heart failure?
Displaced apex beat
3rd heart sounds
Raised JVP
What are the NYHA classes of HF?
Class I: No limitation (Asymptomatic)
Class II: Slight limitation (mild HF)
Class III: Marked limitation (Symptomatically moderate HF)
Class IV: Inability to carry out any physical activity without discomfort (symptomatically severe HF)
Which NYHA class of HF is:
No limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation or shortness of breath.
Class 1
Which NYHA HF class would this be:
Slight limitation of physical activity. Comfortable at rest. Ordinary physical activity results in fatigue, palpitation, shortness of breath or chest pain.
Class 2
Which NYHA HF Class would this be:
Marked limitation of physical activity. Comfortable at rest. Less than ordinary activity causes fatigue, palpitation, shortness of breath or chest pain
3
Which NYHA class of HF is this:
Symptoms of heart failure at rest. Any physical activity causes further discomfort
Class 4
How do you calculate ejection fraction?
stroke volume / end diastolic volume
Symptoms of L sided HF
- Dyspnea on exertion
- Orthopnea (shortness of breath when lying down flat)
- Paroxysmal nocturnal dyspnea (wakes up short of breath at night)
- persistent cough producing mucus
- crackling on auscultation
- fatigue (also present in R sided)
symptoms due to pulmonary oedema
Symptoms of R sided HF
Peripheral oedema
Raised JVP
Tachycardia
Hepatomegaly (backup of blood into IVC)
Ascites (from increased pressure in hepatic vessels)
Fatigue
What is shock?
a life-threatening, generalised form of acute circulatory failure with inadequate oxygen delivery to and utilisation by the cells
What is hypovolaemic shock?
volume of the circulatory system is too depleted to allow adequate circulation to the tissues of the body
What are the 4 types of shock?
Hypovolaemic
Cardiogenic
Obstructive
Distributive
What is cardiogenic shock?
Failure of the pump action of the heart, resulting in a decrease in cardiac output causing reduced end-organ perfusion
hypoperfusion and hypoxia despite adequate volume
What can cardiogenic shock be defined by?
Sustained hypotension
Tissue hypoperfusion
Risk factors for cardiogenic shock
Elderly
MI
Previous heart disease of infarction
What are the aetiologies of cardiogenic shock?
MI
Arrhythmias
Toxic substances
Acute mechanical causes: rupture, chest trauma, valvular incompetence
Infection
Non-adherence with meds
Excessive rise in BP
Cardiomyopathy
Signs and symptoms of shock
Tachycardia
Hypotension
Tachypnoea (increased RR and increased work)
Hypoxaemia
Oliguria
Skin changes: cool, clammy peripheries, cyanosis, sweating
Mental state changes
Signs and symptoms of cardiogenic shock
excluding general shock symptoms, e.g tachycardia, hypotension
Chest pain
Nausea and vomiting
Dyspnoea
Profuse sweating
Confusion/disorientation
Palpitations
Faintness/syncope
Bilateral basal pulmonary crackles or wheeze may occur
Quiet or extra heart sounds
Raised JVP/ distended neck veins
How would you manage shock?
ABCDE approach
Make sure airway is secure and breathing is maintained
Treat underlying cause ASAP
What are the vitals in hypovolaemic shock?
hypotensive
tachycardia
hypoxaemia
increased HR, decreased CO and BP
What are the reversible causes of cardiac arrest?
4Hs & 4Ts
Hypoxia
Hypokalaemia/hyperkalaemia
Hypothermia/hyperthermia
Hypovolaemia
Tension pneumothorax
Tamponade
Thrombosis
Toxin
What are the 2 types of hypovolaemic shock + their causes?
Haemorrhagic: bleeding
Non-haemorrhagic: burns, DKA, severe D&V, excessive use of diuretics, pancreatitis, severe dehydration
What are the symptoms of hypovolaemic shock?
Tachypnoea
Long CRT
Tachycardia
Hypotension
Cold peripheries
Hypoxaemia
Cool and clammy
What is afterload?
force or load against which the heart has to contract to eject the blood
What is preload?
the initial stretching of the cardiac myocytes prior to contraction
What is central venous pressure?
blood pressure in the vena cava as it enters the right atrium
reflects the volume of blood returning to the heart and therefore the volume of blood the heart pumps back into the arteries
What can cause obstructive shock?
PE
Cardiac tamponade
Tension pneumothorax
What happens in distributive shock?
Extreme vasodilation, lowers BP
Capillaries can become leaky
What are the different types of distributive shock?
Septic
Neurogenic
Anaphylactic
What can cause distributive shock?
Anaphylactic: severe allergic reaction
Septic: Severe infection
Neurogenic: spinal cord injury
Which types of shock have a reduced preload?
Hypovolaemic
Distributive
Obstructive: PE, tension PTX
Which types of shock have an increased preload?
Cardiogenic
Obstructive: cardiac tamponade
How do you treat hypovolaemic shock?
Fluid resus
Correct hypovolaemia and hypoperfusion before irreversible organ damage
Blood transfusion in haemorrhagic
What is the pathophysiology of haemorrhagic shock?
- loss of blood volume from ruptured vessels
- EDV + SV decrease
- CO and BP decrease
- Baroreceptors detect
- Catecholamines, ADH and angiotensin II released to cause vasoconstriction, resistance and HR increased
What is obstructive shock?
Obstruction to the forward flow of blood in the great vessels or heart
What is the pathophysiology of distributive shock?
Septic shock: massive vasodilation in inflammatory reaction
Neurogenic: body can’t vasoconstrict so vasodilates
Anaphylaxis: IgE mediated type 1 hypersensitivity reaction, vasodilation
Vasodilation changes distribution of fluid in body
What investigations would you carry out in shock?
ABG (+ lactate)
Glucose
FBC + U&Es
ECG
How do you treat distributive shock?
Fluid resus
Septic: antibiotics
Neurogenic: vasopressors, corticosteroids
Endocrine: corticosteroids
Anaphylactic: adrenaline, antihistamines
Risk factors for an AAA
smoking
family history
increased age
hypertension
male sex (prevalence)
female sex (rupture)
aortic degeneration accelerated in marfans and pregnancy
What should you suspect in a patient with hypotension and atypical abdo pain?
Ruptured AAA
Key presentations of an AAA
Pulsatile and expansile mass in abdomen
Pain in abdo, back, loin and groin
Signs of a ruptured AAA
Hypotension
Atypical abdo symptoms
Syncope, collapse
Shock
What investigation would you do for a suspected AAA?
aortic ultrasound
Differentials for AAA
GI haemorrhage
Mesenteric AA
IBS/IBD
Diverticulitis
Ureteric colic
How do you manage a AAA?
Ruptured or symptomatic: urgent surgical repair
Unruptured: surveillance and treatment of modifiable risk factors
How often would you do an aortic ultrasound for a known AAA?
Annually if the AAA measures 3.0 to 4.4 cm
Every 3 months if the AAA measures 4.5 to 5.4 cm
What are some possible complications of AAA repair?
- Abdominal compartment syndrome
- AKI
- Colitis
What is the screening for AAA?
Routine screening for AAA for all men aged 65 years
What is pericarditis?
inflammation of the pericardium
What is the function of the pericardium?
Restrains volume of heart so it can’t overfill
Protects heart
Provides fluid layer in pericardial cavity to avoid friction
What is acute pericarditis?
new-onset inflammation of pericardium lasting <4 to 6 weeks
What 3 signs characterise pericarditis?
Chest pain
Pericardial friction rub
Serial ECG changes
How does a pericardial effusion occur from pericarditis?
Pericardium inflammation causes cytokines to be released. This causes blood vessels to become more permeable and fluid leaks into pericardial cavity.
Can pericarditis exist without pericardial effusion?
Yes
Majority of time some effusion, but not always
When does cardiac tamponade occur?
When pericardial effusion inhibits stretch of pericardium or happens rapidly
What can cause pericarditis?
- Infectious: viral (EBV, CMV, SARS Cov2), bacterial (TB)
- Autoimmune (Sjorgen, rheumatoid arthritis, SLE)
- neoplastic (secondary metastatic tumours)
- metabolic
- trauma + iatrogenic
- post MI, dressler’s syndrome
- uraemia
viral causes or idiopathic are responsible for 90%
What is Dressler’s syndrome?
late-onset post-myocardial infarction pericarditis
Can occur anywhere up to 3 months after MI
What are the risk factors for pericarditis?
Male
Age 20-50
Transmural MI
Cardiac surgery
Infections
Uraemia or dialysis
Autoimmune disorders
What is chronic constrictive pericarditis?
chronically thickened pericardium
What is chronic pericarditis and its subtypes?
long-lasting, gradual inflammation of the pericardium
signs and symptoms lasting longer than 3 months
subtypes: effusive, constrictive
What is chronic effusive-constrictive pericarditis?
combination of tense effusion in the pericardial space and constriction by the thickened pericardium
What are the clinical criteria for diagnosing acute pericarditis?
At least 2 must be present
- Characteristic chest pain; typically sharp, pleuritic, and relieved by sitting forwards
- Pericardial friction rub
- New widespread concave upwards ST elevation or PR depression on ECG
- Pericardial effusion (new or worsening)
What are the symptoms of pericarditis?
Acute onset, sharp, pleuritic chest pain
Pericardial rub
Chest pain relieved on sitting forward
Fever
Signs of effusion
What investigations should be done for pericarditis?
ECG: saddle shape on ST segment, PR depression
FBC: increase in white cell count
CXR
Echocardiogram
What ECG changes are seen in pericarditis?
Saddle-shaped ST-elevation
PR depression
What are the differentials for pericarditis?
MI
Pneumonia
Pleurisy
PE
Aortic dissection
Pneumothorax
Myocarditis
How would you manage pericarditis?
Give NSAIDs and Colchicine
Check for tamponade
What are the possible complications of pericarditis?
Pericardial effusion
Cardiac tamponade
Chronic constrictive pericarditis
What is a pericardial effusion?
excess fluid collects within the pericardial sac
What can cause pericardial effusion?
Malignancy
Infections (from pericarditis)
Iatrogenic (post surgery)
What is cardiac tamponade?
the accumulation of pericardial fluid, blood, pus, or air within the pericardial space that creates an increase in intra-pericardial pressure, restricting cardiac filling and decreasing cardiac output
What normally happens during inspiration in the RV?
inhaling causes negative pressure, pulling blood into heart. RV expands into pericardial space so it doesn’t affect left heart volume
What happens in cardiac tamponade when the RV can’t expand into the pericardial space?
RV can’t move into pericardial space, so pushes into left instead.
Causes reduction in LV diastolic volume, lower SV and drop in systolic BP during inspiration.
Decrease in systolic BP of greater than 10mmHg is called pulsus paradoxus
What makes up Beck’s triad in diagnosing cardiac tamponade?
Hypotension
Elevated JVP
Muffled heart sounds
What are the signs of cardiac tamponade?
Becks triad
Fall in systolic BP (pulsus paradoxus)
Kaussmaul’s sign
ECG changes
What are the symptoms of cardiac tamponade?
Dyspnoea
Tachycardia
Hypotension
Cold and clammy peripheries
Elevated JVP
Signs of pericardial effusion
What are the differentials for cardiac tamponade?
Constrictive pericarditis
Restrictive cardiomyopathy
Cardiogenic shock
How do you treat cardiac tamponade?
Pericardiocentesis (not as great in smaller effusions or constrictive causes)
NSAIDS + Colchicine (pericarditis)
main point is drain the pericardium
What are the possible complications of cardiac tamponade?
Cardiac arrest
Organ hypoperfusion
What is the action of ACE inhibitors?
inhibit the conversion of angiotensin I to angiotensin II
What drugs can be used to treat hypertension?
ACE inhibitors
Angiotensin II receptor blockers (ARBs)
CCBs
Beta-adrenoreceptor blockers
Diuretics
others: Alpha-1 adrenoreceptor blockers
Centrally acting anti-hypertensives
Direct renin inhibitors
Examples of ACE inhibitors?
Ramipril
Perindopril
Enalapril
What are the indications for ACE inhibitors?
HF
Hypertension
Diabetic nephropathy
What are some possible adverse effects of ACE inhibitors cause by inhibting the breakdown of bradykinin?
Persistent dry cough
Rash
Anaphylactoid reactions
What are some adverse effects of ACE inhibitors?
Hypotension (related to AGT 2)
Acute renal failure (AGT 2)
Hyperkalaemia (AGT 2)
Teratogenic in pregnancy (AGT2)
Cough (related to kinins)
Rash (kinins)
Anaphylactoid reactions (kinins)
What are the contraindications of ACE inhibitors?
Pregnancy
History of angio-oedema
Diabetics on aliskiren with a eGFR below 60mL/minute
What are angiotensin II receptor antagonists (ARBs) used for?
Hypertension
HF when ACEi is contraindicated
Diabetic nephropathy
What are the contraindications of ARBs?
Pregnancy
History of angio-oedema
Diabetics on aliskiren with a eGFR below 60mL/minute
Breastfeeding women
What are some adverse effects of ARBs?
Hypotension (esp if volume depleted)
Rash
Potential for renal dysfunction
Hyperkalaemia
Angio-oedema
What is the action of ARBs?
Block angiotensin 2 by acting on AT-1 receptor
Examples of calcium channel blockers
Dihydropyridine:
- Amlodipine
- Felodipine
Benzothiazepines:
- Diltiazem
Phenylalkylamine:
- Verapamil
What are calcium channel blockers used for?
Hypertension
IHD – angina
Arrhythmia (tachycardia)
What are some contraindications of CCBs?
HF
Cardiac outflow obstruction
Cardiogenic shock
Avoid within 1 month of MI (amlodipine fine)