Cardiovascular drugs 1 Flashcards
How is atrial fibrillation characterised on ECG
Irregularly irregular, no p waves, absence of isoelectric baseline, variable ventricular rate
What is the pathophysiology of A fib
- Chaotic atrial electrical activity
- Fibrosis and loss of atrial muscle mass related to: ageing, chamber dilatation (due to HTN, valve disease), inflammation, genetic
Give 5 risk factors for A fib
- HTN
- Valvular heart disease
- Coronary artery disease
- Cardiomyopathy
- Congenital heart disease
- Previous cardiac surgery
- Pericarditis
- Lung disease- PE, pneumonia, COPD
- Hyperthyroidism (always do TFTs if patient presents with AFib)
- Alcohol
Outline the classification of A fib
Lone AF
- usually younger patient, no established cause
Paroxysmal (<7 days)
Persistent (>7 days)
Permanent (>7 days +/- cardioversion)
What are the clinical features of AFib?
- Asymptomatic
- Palpitations
- SOB
- Chest pain
- Syncope
- Pre syncope
- Heart failure
What are the categories of treatment options for AFib?
- Rate control
- Rhythm control
- Anticoagulation
How would you treat recent onset AF in
a) compromised patient
b) not compromised patient
a) DC shock
b) Pharmacotherapy
How would you treat recent onset AF of
a) <48hr duration
b) >48hr duration
How do you determine this?
Symptoms onset will help pinpoint exactly when it started
a) Attempt rhythm control
b) Rate control- after 48hrs the risk of thromboembolism increases significantly
When is rhythm control preferred?
- For symptom improvement
- In younger patients
- HF related to AF
- Adequacy of rate control
How do you rate control in acute AF without HF?
Beta blocker or CCB (Diltiazem, Verapamil)
2nd line: add digoxin
How do you rate control in acute AF with HF?
Digoxin, Amiodarone
2nd line: amiodarone
How do you rate control in permanent AF or paroxysmal AF?
Beta blocker or CCB
2nd line: add digoxin
What complication can occur when using the rate control drugs in combination?
Beta blocker + CCB can lead to heart bloc
- although not completely contraindicated
- may be of use in young patient
For the the following indications provide the rhythm control drug
a) Acute cardioversion, normal heart
b) Acute cardioversion, abnormal heart
c) Maintain sinus rhythm, normal heart
d) Maintain sinus rhythm, abnormal heart
a) Flecainide, sotalol (non selective)
b) Amiodarone
c) Flecainide, sotalol
d) Amiodarone
Outline the mechanism of action of beta blockers
- B1/B2 adrenergic blockade therefore blockinf the effects of adrenaline/NA at B1 receptor
- Slows down contractility og the heart by inhibting cAMP formation, such that PK-A is not activated. The L type calcium channel is not phosphorylated and therefore there is not an influx of Ca
Give an example of a
a) Non cardioselective beta blocker
b) Cardioselective beta blocker
c) Vasodilatory beta blockers
a) Propanolol, carvedilol, sotalol
b) Atenolol (>90% renal clearance), bisoprolol, esmolol, metoprolol (liver clearance), nebivolol
c) Labetalol, carvedilol
Which rate limiting CCBs are used to treat AF?
- Verapamil
- Diltiazem
Give 3 examples of dihydriopyridine CCBs
- Amlodipine
- Nifedipine
- Felodipine
- Lercanidipine
- Nimodipine (used in subarachnoid haemorrhage as it has a high lipid solubility and can cross BBB)
What is the CHA2DS2VaSc score?
If greater or equal to 2 how do you proceed?
A scoring system which calculates the risk of stroke in patients with AF. Consider factors such as congestive HF, HTN, age, DM, previous stroke, TIA or thromboembolism, vascular disease and sex
Warfarin or DOAC
What is the HAS-BLED score?
What does a score greater than or equal to 3 mean?
A scoring system which estimates bleeding risk for patients on anticoagulation in patients with AF. Considers factors such as: HTN, abnormal renal/liver function, past stroke, bleeding Hx, labile INRs, elderly, drugs/alcohol
Significant risk of bleeding
What other treatments are used in AF?
- Radiofrequency catheter or cryo-ablation: used in the younger patient
- Left atrial appendage occlusion (LAAO): most clots that form in heart, form here. This procedure can reduce risk of strokes in the older patient
What are the categories of drugs used to treat stroke
- Fibrinolysis
- Antithrombotics (aspirin, clopidogren, warfarin or DOAC)
- Lipid modification
- HTN treatment
Consider lipid modification for primary and secondary prevention of stroke/MI
When should you refer to lipid specialist?
What should be excluded?
Total serum cholesterol >7.5mmol/L + FHx of premature CAD
Total serum cholesterol >9mmol/L
Exclude secondary causes of hyperlipidaemia: excess alcohol, uncontrolled DM, hypothyroidism, liver disease, nephrotic syndrome
When is primary prevention indicated?
What should be used?
- People with >10% 10yr risk of developing CVD
- Adults with T1DM
- Those with CKD
Offer atorvastatin