Cardiovascukar System Flashcards
Class I anti-arrthymic drugs
Membrane stabilising drugs ; Na+ blockers
Disopyramide
Lidocaine
Flecainide/ propafenone
When are flecainide/propafenone contraindicated
Asthma
Severe COPD
Avoid in structural/ ischaemic heart disease
Class II anti arrthymic drugs
Beta blockers
Propranolol
Esmolol
-olol
Class III anti arrthymic drugs
K+ channel blockers
Amiodarone
Sotalol
Dronedarone
Amiodarone dose after electrical cardioversion
4 weeks before and 12 months after to increase success
Dronedarone side effects
Hepatotoxicity and HF side effect
Class IV anti arrthymic drugs
Calcium channel blockers (rate limiting)
Verapamil
Diltiazem
Diltiazem is it a licensed or unlicensed CCB
Unlicensed
Other anti arrthymic drugs
Adenosine
Digoxin
Advantage of digoxin
Effective in sedentary patients with non - paroxysmal AF and in patients with associative congestive HF
What is atrial fibrillation
Abnormal, disorganised electrical signals fired cause the atrial to quiver or fibrilate = rapid and irregular heartbeat
Symptoms of atrial fibrillation
Heart palpitations = pounding/fluttering
Dizziness, SOB, tiredness
Complications of atrial fibrillation
Stroke and heart failure
Type of atrial fibrillation
Paroxysmal - episode stop within 48hrs without treatment
Persistent - episode more than 7 days
Permanent - present all the time
Two types of treatment
Rate control - control ventricular rate
Rhythm control - restores and maintains sinus rhythm
What are the two types of cardioversion
Cardioversion is type of rhythm control
1. Electrical - direct current
2. Pharmacological - anti arrthymic
When is rhythm control not suitable
If symptoms more than 48 hours and increases risk of stroke
When is electrical cardioversion preferred
If more than 48 hours
Must wait until fully anticoagulated for 3 weeks before cardioversion and continue four weeks after
What type of cardioversion if haemodynamically unstable
Electrical - give parental anticoagulant and rule out left atrial thrombus immediately before procedure
Treatment for acute new onset of AF
Life threatening haemodynamic instability - electrical cardioversion
Without life threatening haemodynamic instability - < 48 hours = rate or rhythm control (electrical or Amiodarone/flecainide
>48 hours = rate control (verapamil, beta blocker)
Maintenance treatment for atrial fibrillation
First line: rate control
Beta blockers (not sotalol) , rate limiting CCB, digoxin
Mono therapy —-> dual therapy —-> rhythm control
Second line; beta blockers or oral anti arrthymic drug
Ie. Sotalol, Amiodarone, flecainide, propafenone, Dronedarone
Paroxysmal and symptomatic AF treatment
Ventricular or rhythm control = standard BB or oral anti arrthymic drug
Pill in pocket if infrequent episodes - self treatment = flecainide or propafenone restores sinus rhythm if episode occurs
Atrial flutter treatment
Similar to AF but catheter ablation more suitable
When to give Anticoagulant in stroke prevention
If risk of thromboembolic stroke > the risk of bleed HAS-BLED
Risk of stroke tool and meaning
CHA2DS2VASC TOOL
C - chronic heart failure or left ventricular dysfunction
H- hypertension
A2- age ur+
D- diabetes mellitus
S2- stroke/TIA/VTE history
V- vascular disease
A- 65-74 years
Sc- sex category ie. Female
What score on CHA2DS2VASC to give anticoagulant
If 2 or more
No anticoagulant if male =0 or female = 1
New onset of AF treatment
Parenteral anticoagulant
Diagnosed AF treatment
Warfarin or NOAC
What is NOAC
Novel oral anticoagulant in non valvular AF with >= 1 risk factor ( 75+, heart failure, htn, dm, previous stroke or TIA
What is the different types of ventricular tachycardia and the treatment
Pulseless or fibrillation - immediate defibrillation and CPR, IV Amiodarone is given refractory to defib
Unstable sustained VT - direct current cardioversion, if this fails give IV Amiodarone and repeat direct current
Stable sustained VT - IV anti arrthymic drug (Amiodarone preferred)
Non sustained VT- beta blocker
Maintenance of ventricular tachycardia treatment
For high risk of cardiac arrest-
Most patients = cardioverter defibrillator implant Some pt also require drug ; Sotalol, bb alone or bb with Amiodarone
What is torsade de pointes
Prolonged QT interval
Treatment and cause of prolonged QT interval
Treat - magnesium sulphate
Causes -Sotalol and other drugs that prolong QT interval, hypokalaemia and bradycardia
Paroxysmal supraventricular tachycardia
Terminates spontaneously or with reflex vagal nerve stimulation or. Valsalva manoeuvre, carotid sinus massage or immersing face in ice cold water— > IV adenosine (CI- COPD/ASTHMA)— ->IV verapamil
Treatment of haemodynamically unstable paroxysmal supraventricular tachycardia (PST)
Direct current cardioversion
Treatment of recurrent paroxysmal supraventricular tachycardia
Catheter ablation OR drugs (verapamil, Diltiazem, BB, flecainide, propafenone
Amiodarone
Class III anti arrthymic used in supraventricular and ventricular arrhythmia
Amiodarone dose
Loading dose 200mg TDS for 7 days
200mg BD FOR 7 days and then
200mg OD as maintenance
Amiodarone side effects -eyes
Corneal micro deposits
Pt counselling ; night time glares when driving
Optic neuropathy/neuritis (blindness)
Pt counselling : STOPif impaired vision
Amiodarone side effects ; skin
Phototoxicity (burning, erythema)
Slate grey skin on light exposed areas
Pt counselling; shield skin from light during treatment, use wide spectrum, high spf for months after stopping
Amiodarone side effects ;nerves
Peripheral neuropathy
Pt counselling; numbness, tingling in hands and feet, tremors
Amiodarone side effects ;lungs
Pneumotitis, pulmonary fibrosis
Pt counselling: SOB, dry cough
Amiodarone side effects: liver
Helatotoxicity
Pt counselling ; report jaundice, nausea, vomiting, malaise, itching, bruising, abdominal pain - due to 3x raised liver transaminases)
Amiodarone side effects; thyroid dysfunction (Amiodarone contains iodine)
Hyperthyroidism (eg. Weight loss, heat intolerance, tachycardia)
- give carbimazole if necessary and withdraw Amiodarone
Hypothyroidism (weight gain, cold intolerance, bradycardia)
-Start levothyroxine without withdrawing Amiodarone
Amiodarone monitoring
Annual eye test
Chest c ray before treatment
Liver function tests every 6 months
Monitor TSH, T3,T4 before treatment and every six months
Blood pressure and ECG (can cause hypotension and bradycardia)
Serum potassium (causes hypokalaemia, enhances arrthymogenjc effect of Amiodarone)
Amiodarone interactions
Has a long half life ~ 50days
Danger of interactions for several months after stopping
- increased plasma Amiodarone concentrations = grapefruit juice (enzyme inhibitor)
-Amiodarone is an enzyme inhibitor * warfarin, phenytoin, digoxin (half dose)
-increased risk of myopathy = statins
- bradycardia, AV block and myocardial depression = beta blockers, rate limiting CCB ie. Verapamil and Diltiazem
- QT prolongation = increased risk of ventricular arrthymia = quinolones, macrolides, TCAs, SSRIs, lithium, quinine, hydroxychloroquine, anti-malarial (chloroquines, mefloquine), antipyschotics(esp. sulpride, pimozide, amisulpride)
Digoxin class and moa
Cardiac glycoside
1-2mcg /L
High risk drug
Increases force of myocardial contraction (positive into rope)
Reduces conductivity in the AVnode (negative chronotrope)
Therapeutic level of digoxin
1-2mcg/L (desired plasma concentration 6 hours after dose)
Regular monitoring is not required during maintenance treatment unless toxicity suspected OR in renal impairment (Renally cleared)
Digoxin dose
Loading doses required due to long half life
Maintenance OD : atrial flutter and non - paroxysmal AF in sedentary patients ; 125-250mcg
Worsening or severe heart failure (in sinus rhythm); 62.5-125mcg
Different bioavailability’s of different formulation for digoxin
Elixir = 75%
Tablet = 90%
IV =100%
Risk and Signs of digoxin toxicity
Risk of toxicity in hypokalemia, hypomagnesaemia, hypercalcemia, hypoxia and renal impairment
Symptoms ; bradycardia/heart locks
-nausea , vomiting and diarrhoea, abdominal pain
- blurred or yellow vision
- Confusion, delirium
- Rash
Treatment for digoxin toxicity
Withdraw and correct electrolyte imbalance
Digoxin specific antibody ; for life threatening ventricular arrhythmias unresponsive to atropine
Digoxin interactions
Ihypokalaemia predisposes digoxin toxicity
- diuretic (loop/thiazide), B2 agonist, steroid, theophylline (if potassium levels < 4.5mmol/L; give potassium supplements or potassium sparing diuretics (preferred)
Increased plasma digoxin concentration = toxicity
- Amiodarone (half digoxin dose), rate limiting CCB, macrolides, ccilosporin (enzyme inhibitors)
Decreased plasma digoxin concentration = sub therapeutic = St John’s wort, rifampicin ( enzyme inducers)
Reduced renal excretion = toxicity (digoxin renally excreted)
- NSAIDs, ACEi/ARBs
Digoxin interaction pneumonic
CRASED
C - CCB (VERAPAMIL)
R - RIFAMPICIN
A - AMIODARONE
E- ERYTHROMYCIN ( macrolide)
D- DIURETIC
Two types of venous thromboembolism (VTE)
Venous thromboembolism
1. Deep vein thrombosis (DVT)
2. Pulmonary Embolism (PE)
What is DVT
A blood clot occurs in a deep vein, usually in calf of one leg
What is pulmonary embolism
Detachment of blood clot which travels to lungs and blocks the pulmonary artery
VTE risk assessment
For all pt admitted to hospital
- immobility
- obesity BMI> 30
- malignant disease
- 60+ years
- personal history of VTE = thrombophyllic disease, 1st degree of relative with VTE
- HRT / Combined contraception = varicose veins with phlebitis
- pregnancy = critical care, significant co - morbidities.
