Antiarrhythmic drugs Flashcards
1
Q
Verapamil hydrochloride
A
- Treatment of superventricular arrhythmias
- Calcium channel blocker
2
Q
Amiodarone
A
- Treatment of both superventricular arrhythmias and ventricular arrhythmias
- Potassium channel blocker
3
Q
Lidocane hydrochloride
A
- Treatment of ventricular arrhythmias
- Sodium channel blocker
4
Q
Digoxin
A
- Treatment of rapid arterial fribrillation
5
Q
Cardiac pacemaker action potential in arrhythmias
A
- If the impuse is brater at another node compared to SN
- Heartbet driven by ventricles if initiated at purkinje fibres so larger QRS
6
Q
Class 1 antiarrhythmatics
A
- Na+ channel blockers
- Decrease the influx of Na+ into cardiac myocytes during phase 0 causing slow depolarisation
- Decrease conduction of AP thus wide QRS slow heart rate
7
Q
Moderate 1a arrhythmatic drug
A
- decrease influx of sodium into cardiac myocytes slow depolarisation
- Longer refractory period decrease in conduction velocity
8
Q
1c Antiarrhythmatic drug
A
- Slower depolarisation as lower influx of Na+
- No change in refactory
9
Q
Fleccanide
A
- Na+ channel blocker
- Management of AF and Paroxysmal superventricular tachicardis inhibiting conduction causing arrhithmyas
- Increase threashold for depolarisation
- Slow unbinding during diastole
- Prolong refractory peroid of heart
- Block ryanodine receptor reduction of calcium release from sarcoplasmic reticulum
10
Q
Class II antiarrhythmatic drugs: Propranolol
A
- Propranolol non selective Beta adrenogetic antagonist used to treat superventricular tachychadias
11
Q
Side effects of Propranolol
A
- SA node depression sinus bradycardia and heart block
- Fatigue, sedation, sleep disturbances and bronchospasm
- Hypoglycemia
- Ineracts with CCB
12
Q
Selective beta adrenageric blockers
A
- Atenolol
- Esmolol
- Mertropolol
13
Q
How do beta blockers work
A
- Beta bockers with noradrenaline and adrenaline bind to B1 adrenogic receptors
- Beta blockers bind to cAMP it fails to activate PKA
- PKA doesn’t activate T-type calcium channels allow influx of Ca2+ into cell
- PKA doesn’t activate SR for the release of Ca2+ into cell
- Doesn’t activate myosin phosphorylation which results in stronger contraction
14
Q
Beta blocker effect on ECG
A
- Reduce firing of pacemaker cells decrease heart rate and lengthen PR interval
15
Q
How is the ventricular muscle effected by b1 adrenergic receptor
A
- Decrease in Ca2+ influx into phase 2
- Decrease Ca2+ in cell
- Decrease force of contarction
16
Q
Cautions with propranolol
A
- Reduce effect of catecholamines
- Decrease contractility and ionotropic effect
- Decrease cellular excitability
- Prolonged diastole
17
Q
Amiderone
A
- Treatment of recurrent hemodynamically unstable VT and reoccouring VF
- Slows rate of repolarisation
- Prolonged action potentional and QRS
- Block cacium channel longer to leave the cells
- Deacrease function of Voltage gated Na+, K+ and Ca2+
18
Q
Structure of amiodarine
A
- Contains iodine in its structure therefore is very lipophilic
- Can cause toxicity half life of 100 days with high BD causing liver disfunction
19
Q
Class IV drugs: CCB
A
- Target pacemaker and non pacemaker cells
- Decrease myocardial contactility
- Decrease myocardial contraction and conduction velocity
- Selective vasular smooth muscle to vasodialate
20
Q
Non-dihydropyradine: verapamril
A
- Decrease L type calcium channel
- Decrease Ca2+ into cell
- Decrease firing rate and heart rate with conduction velocity
- Longer PR interval
- Slight block in AV node
21
Q
Adverse effects of CCB
A
- Heart block and SA node depression
22
Q
Drug interaction of CCB
A
- Cannot be taken with Beta blockers decreases AV node
23
Q
Contraindication of CCB
A
- Arterial flutter
- Bradycardia
- Cardiogenic shock
- Heart failure
- Hypotention
24
Q
Digoxin
A
- Cardiac glycoside used to treat mild to moderate HF
- Ventricular response to rate control
25
Q
Adenosine
A
- Rapid reversion to sinus rhythm of paroxysmal superventricular tachycharia aids diagnosis
