Cardiovascular System Flashcards
What is arrhythmia?
Abnormal rhythm and rate
Due to problems with the electrical conducting system of the heart
Symptoms of arrhythmias
Palpitations
Abnormally fast, slow or irregular pulse
Dizziness or feeling faint
Shortness of breath
Chest pain which sometimes develop
What can cause arrhythmias?
May occur as complications of heart conditions
Coronary heart disease
Heart valve disease
Hypertension
Ageing
Cardiomyopathy (disorder of the heart muscle)
Congenital (from birth) abnormalities
Different types of arrhythmias?
Ectopic beat
AF (main one for the exam)
Paroxysmal AF
Atrial flutter
Paroxysmal supraventricular tachycardia
Ventricular tachycardia
Supra ventricular arrhythmias
Treatment of arrhythmias?
Medication
Cardio version
Artificial pacemakers
Implantable cardioverter defibrillation
Aims of treatment of arrhythmias?
Reduce symptoms
Prevent complications
What risk calculators are needed for AF?
Stroke risk
Bleeding risk
How is stroke risk calculated?
CHA2DS2-VASc
Risk factors; CHF, hypertension, Age (75+ 2 points 65-74 is 1), Diabeties, stroke/TIA/VTE , vascular disease, sex (female is 1)
Low risk = men score of 0 and women with score 1
Higher points would require treatment with anticoagulation as long as risk > than risk of bleeding
How is bleeding risk calculated?
Has bled tool replaced by ORBIT
Score of 0-7
Factors; males with HBA1C <130 g/L or females <120, prior history of bleeding, age > 74, EGFR <60 mL/min/1.73m2 and taking anti platelets
What is torsade de pointes?
Prolonged QT interval
Self limiting
Can lead to ventricular fibrillation
Treat IV Mg sulphate
What drugs are used in rate control?
Beta blockers (NOT sotalol)
Verapamil
Diltiazem (unlicensed)
Drug treatment usually mono-therapy but combine if mono-therapy fails
Digoxin only considered for initial rate control with non paroxysmal AF with predominantly sedentary or others is unsuitable, accompanied by HF and AF
Drugs used for rhythm control after cardioversion?
1st line is Beta blockers
If not
Flecanide
Amiodarone
When to avoid flecanine
Avoid if also have isachaemic or structural heart disease, HF etc
How to treat supraventricular arrhythmias?
Verapamil, adenosine and cardiac glycosides
How to treat ventricular arrhythmias?
Lidocaine and sotalol
How to treat supraventricular and ventricular arrhythmias ?
Amiodarone and beta blockers
What is digoxin?
Cardiac glycoside
Increases force of myocardial contraction and reduces conductivity in a the atrio ventricular node
Useful in controlling AF, atrial flutter and HF (for pts with sinus rhythm)
Has a long half life maintenance dose around 125-250 mcg)
Dose dependent on renal function
What is the therapeutic range of digoxin?
0.7 to 2.0 nano grams / mL
What is toxicity level of digoxin?
1.5 to 3
Toxicity can occur within normal range (0.7 - 2)
Contraindications for digoxin?
Ventricular tachycardia and fibrillation
Heart conduction problems
Signs of digoxin toxicity?
Arrhythmias
Cardiac conduction disorder
Diarrhoea
Dizziness
Nausea and vomiting
Skin reactions
Vision disorders (yellow)
Risk factors of digitalis toxicity?
Hypokalaemia
Hypomagnesaemia
Hypercalcaemia
Hypoxia
Special care in elderly; more susceptible to digitalis reduce dose as they have poor reduced kidney function
Interactions with digoxin
CCB (increase concentration)
Rifampicin (decrease concentration)
Amiodarone (half the digoxin dose)
St John’s wart (decrease concentration)
Erythromycin
Diuretics
TCS, venlaflaxine, TCA, venlafaxine, trazadone
What happens if digoxin toxicity occurs?
Withdraw digoxin
Serious manifestations require urgent specialist care
Life threatening overdose - reverse with digoxin specific antibody fragments
Monitoring requirements for digoxin?
Plasma- digoxin concentration
Serum electrolytes
Renal function (reduce dose in renal impairment)
Tranexamic Acid
Inhibits fibrinolysis (prevents you from bleeding)
Prevents bleeding (e.g surgery, dental extraction)
Management of menorrhagia ( 1 g TDS for up to 4 days)
Used in hereditary angioedema, epistaxis and thrombocytes overdose
Two types of venous thromboembolism?
DVT clot in body usually the legs
PE blockage of artery in lungs
Venous thromboembolism prophylaxis
All patients admitted to hospital need to be assessed for their risk of VT on admission
Who are high risk for VT?
Substantial reduction in mobility
Obesity >30 BMI
Malignant disease
Hx of VT
Thrombophilic disorder
Patient over 60 years
Pregnancy / co-morbidities
Mechanical prophylaxis for venous thromboembolism?
Anti embolism stockings
Continue until patients is mobile
Move around and raise legs etc
Pharmacological PROPHYLAXIS for venous thromboembolism?
Undergoing general orthopaedic surgery who are at high risk
Choice depends on type of surgery
Stop depends on condition / surgery or when patient mobile again (no fixed time)
LMWH suitable for all types of patients e.g dalteparin, tinzaparin and enoxaparin
Fondaparinux sodium to patients undergoing (hip/knee replacement surgery, hip fracture, GI bariatic)
Oral anticoagulation for thromboprophylaxis following knee / hip surgery
Treatment for Venous thromboembolism?
Use LMWH (enoxaparin, dalteparin and tinzaparin) for initial treatment of DVT and PE
Give IV unfractionated heparin as alternative
Start oral anticoagulant (usually warfarin) at same time as LMWH or unfractionated heparin; once out of hospital continue oral
Venous thromboembolism in pregnancy
Heparins don’t cross the placenta
LMWH preferred (lower risk of osteoporosis and of heparin induced thrombocytopenia) and are eliminated more rapidly in pregnancy, dose alteration is required
What are LMWH?
Dalteparin
Tinzaparin
Enoxaparin
What is common side effect of LMWH?
Haemorrhage - Withdraw heparin or LMWH if this occurs
Osteoporosis
Heparin-induced thrombocytopenia (can manifest 5 to 10 days after)
Hyperkalaemia; heparin inhibits aldosterone secretion, high risk DM and CKD monitor 7+ day use
What is reversal agents for LMWH?
Promoting sulphate
Partial reversal agent
3 types of strokes
Transient ischaemic stroke (TIA); aka mini stroke <24 h
Intracerebral haemorrhage
Acute isachaemic stroke (full blown stroke) >24 H
Signs of stroke
Face dropped
Arm weakness
Speech slurred
Time (999)
F.A.S.T
TIA treatment
300 mg Aspirin daily OR alternatively 75 mg clopidogrel immediately until established diagnosis
Once diagnosed;
Secondary prevention; High intensity statin if not already taking
Symptoms usually resolve within minutes or a few hours at most if not = STROKE
Short term treatment of Acute Isachaemic stroke?
Timing important;
Alteplase within 4.5 hours from onset of symptoms
300 mg Aspirin or clopidogrel given 24 hours after alteplase for 14 days
Anticoagulants not recommended except for patients with AF
Long term management for isachaemic stroke?
Clopidogrel
MR dipyridamole 200 mg and aspirin IF clopidogrel is CI
MR dipyridamole alone IF aspirin and clopidogrel is CI
Aspirin alone IF clopidogrel and dipyridamole is CI
High intensity statin treatment 48 hours after
Monitor BP target for <130/80 mmHg
Advice patients on lifestyle changes (modify diet, exercise, weight alcohol intake, smoking)
Intracerebral haemorrhage treatment
Surgery to remove haematoma and relieve intracranial pressure
DONT GIVE ANTICOAGULANTS - reverse effects expect for pts DVT/PE not given even in AF patients
Avoid statins unless CV event outweighs risk of haemorrhage
Aspirin only given with patients of cardiac isachaemic event
BP measured and treatment initiated
What are anticoagulants used for?
Prevent thrombus formation in veins
Examples. Warfarin, acenococoumarol and phenindione
Antagonise vitamin K
Takes at least 48 to 72 hours to get the full effect (oral)
Injections give a immediate effect e.g give heparins
Pregnancy and warfarin
Teratogenic
Cross the placenta leading to foetal abnormalities
Avoid esp in the 1st and 3rd trimester and last few weeks of pregnancy as delivery as increase in bleeding risk
Risk of haemorrhage increased by vitamin K deficiency
Interactions with warfarin?
Increase warfarin; miconazole, antifungals, benzafibrate, amiodarone, cranberry juice, pomegranate, greeny fruit and veg
Increases bleeding risk; antidepressants, aspirin
Decreases warfarin; carbamazepine, alcohol, St John’s wart
MHRA warnings with warfarin?
Risk interactions with treatment of hepatitis C- closely monitor INR
Calciphylaxis - rare skin rash
Warfarin target value INR 2.5 for?
Treatment of DVT and PE
AF
Cardioversion
Dilated cardiomyopathy
Mitral stenosis
Warfarin INR target value of 3.5 ?
Recurrent DVT and PE or mechanical prosthetic heart valve
What is a target value?
Target the INR should be rather than a given range
INR measured can be 0.5 above and below the target value if more = adjustment is required from the dose
Warfarin advantages and disadvantages?
+ can be used renal impairment patients
+ effects are reversible
- regular INR testing
- lots food and drug interactions
Warfarin main side effects
Nose bleeds; < 10 mins is normal
Haemorrhage
Bleeding gums
Bruising
Caliphylaxisl report painful skin rash = risk factor end stage renal disease
When to stop warfarin
Bleeding OR if INR is >8; stop warfarin and give vitamin K by IV (restart INR <5)
No bleeding and INR >8; stop warfarin and given vitamin K orally (restart INR <5)
No bleeding and INR 5-8; withold one or two doses and reduce subsequent maintenance doses
Peri operative anticoagulants
Stop warfarin 5 days before elective (planned) surgery
High risk patients of VT stopping warfarin before surgery maybe given LMWH which is stopped 24 hours before surgery
Emergency surgery which can be delayed 6-12 hours give IV vitamin k
If surgery cant be delayed give vitamin K and prothrombin complex
Anticoagulant and antiplatelet therapy?
Higher risk of bleeding with clopidogrel and warfarin than aspirin and warfarin
Heparin
Short duration of action compared LMWH
‘Standard’ - unfractionated
Used for high risk patients as its effects are shorter; but this means more doses
Can be used in pregnancy doesn’t cross the placenta
LMWH examples
Dalteparin, enoxaparin and tinzaparin
LMWH used?
Used prophylaxis and treatment of DVT, PE and MI
Preferred over heparin; effective and lower risk of heparin-induced thrombocytopenia
Doesn’t require monitoring
Longer duration of action then heparins can be given OD s/c = convenient
Antiplatelets used for?
aspirin, clopidogrel and dipyridamole
Decrease platelet aggregation and inhibit thrombus formation in the arterial circulation
No benefit for primary prevention only secondary
PPI given for patients high risk of bleeding (over 65+, NSAIDs etc)
Rivaroxaban
MHRA alert; strengths 15 mg+ to be taken with food
Prophylaxis of stroke and systemic embolism in patients with non-valvular AF with at least 2 of the following risk factors;
CHF, hypertension, previous stroke/TIA, age > 75 or DM
S/e; anaemia, constipation, diarrhoea, dizziness, headache
Apixaban
Reduced to 2.5 BD for prophylaxis of stroke due to non-valvular AF with at least 2 of the following;
Age (80+), Body weight (less 60) CrCl (greater 133) Otherwise 5 mg is standard dose
S/e; anaemia, haemorrhage, nausea and skin reactions
Edoxaban
Prophylaxis of stroke and systemic embolism in non-valvular AF, in patients with at least one risk factor such as CHF, hypertention, age 75+, DM, previous stroke or TIA
30 mg OD body weight up to 61 kg OR 60kg and above
S/e abdominal pain, anaemia, dizziness, haemorrhage, headache, nausea, skin reactions
Dabigatran etexilate
Avoid CrCl less 30 mL/min ; assess renal function before at least annually
Prophylaxis of stroke and systemic embolism in non-valvular AF and with one or more risk factors such as previous stroke or TIA symptomatic HF, age 75+, DM or hypertention
Special container 4 months expiry
S/E; anaemia, diarrhoea, GI discomfort, haemorrhage
Reversal agents for DOACS
Apixaban and rivaroxaban; Andexanet Alfa (ondexxya)
Dapigatran etexilate; idarucizumab (praxbind)
Edoxaban has no reversal agent
Dabigatran, apixaban and rivoroxaban
Direct thrombin inhibitors (factor Xa)
Rapid onset of action
Prophylaxis VTE in adults after hip/knee surgery and prophylaxis of stroke and systemic embolism
FBC, LFT and U&E recommended annually if not renal impairment (more U&E if renal impairment)
Limited by renal impairment
Monitor signs; bleeding, anaemia, stop if severe bleeding occurs
Common s/e haemorrhage
What patients are high risk of developing hyperlipidaemia?
Diabeties
Chronic kidney disease
Familial hypercholestrolaemia
Risk increases with age (>85 years at high risk esp if smoke/hypertention)
10 year risk of CVD >10%
Drugs; antipsychotics, immunosuppressants, corticosteroids, antimalarials
CVD measures for primary prevention
Provide lifestyle advice to all patients at high risk; diet, exercise, weight management
If above not effective give statins as first line choice
CVD measures for secondary prevention
Offer statins to ALL
Statins for CVD
Statins reduce the risk of CVD
1st drug of choice in primary and secondary prevention CVD
Address secondary causes of dyslipidaemia before starting statins (uncontrolled DM, hepatic disease, nephrotic syndrome and excessive alcohol consumption)
Correcting hypothyroidism may resolve lipid abnormality (treat patients itch hypothyroidism with thyroid replacement first)
What is a high intensity statin?
Atorvastatin; 20 mg, 40 mg and 80 mg
Rosuvastatin; 10 mg, 20 mg and 40 mg
Simvastatin; 80 mg
Primary prevention for statins for CVD
Give high intensity statin for 10 year risk >10%
High intensity statin is one that produces a greater LDL-cholesterol reduction than simvastatin 40 mg (or = greater atorvastatin 20 mg)
Patients over 35 years help reduce risk of non fatal MI
Secondary prevention with statin for CVD
Atorvastatin 80 mg recommended
Give statins to all patients with type I diabeties (esp those > 40 years and have diabeties for over 10 years, established nephropathy or other risk factors
Statin and blood test
Total cholesterol
HDL cholesterol
Non HDL cholesterol
3 months after starting
Types of cholesterol
Total cholesterol; total cholesterol in your blood (5 or below)
HDL; good cholesterol (1/+)
LDL or non-HDL; bad cholesterol (3 or below for LDL and 4 or below for non HDL)
Triglycerides; 2.3 or below (fat lipids)
Diagnosis for hyperlipidaemia
6 mmol/L total cholesterol
Treatment lines for high lipids?
First line statins
Second line is ezetimbe (if statin not effective or CI)
Fenofibrate maybe added to statin if triglyceride is high (SPECIALIS USE NOW)
Then consider nicotine acids, bile and sequestration and omega 3 fatty acid compounds
Statin and fibrate interaction
Statin + fibrate (or nicotine acid) increase risk of s/e; rhabdomylosis
Especially statin + gemfibrozil (fibrate) increase rhabdomylosis considerably