long term management of cardiac tachyarrhythmias

Question 1

what are options for long term management of cardiac tachyarrhythmias

Answer 1

• anti arrhythmic drug therapy
• ablation therapy
• device therapy

Question 2

what are class 1 drugs

Answer 2

membrane depressant drugs that reduce the rate of entry of Na into the cell (sodium channel blockers)

slow conduction, delay recovery and reduce the spontaneous discharge rate of myocardial cells

lengthen the action potential

Question 3

what is class 1a drug

Answer 3

Disopyramide

lengthens action potential

Question 4

what is class 1b drug

Answer 4

Lidocaine, mexiletine

shortens action potential

Question 5

what is class 1c drug

Answer 5

Flecainide, propafenone

no effect on action potential

Question 6

what are class 2 drugs

Answer 6

these are anti sympathetic drugs that prevent the effect go catecholamines on the action potential

most are beta1 blockers and suppress the AV node conduction, which may be effective in preventing attacks of junctional tachycardia, and may help to control the ventricular rate during paroxysms of other forms of SVT

advised to use beta blocker therapy either alone or in combination with other anti arrhythmic drugs in patients with symptomatic tachyarrhythmias

Question 7

what is class 2 drug

Answer 7

Atenolol, Acebutolol, Bisoprolol, Propanolol, Esmolol

block b-adenoceptors

Question 8

what are class 3 drugs

Answer 8

these prolong the action potential usually by blocking the rapid components of the delayed rectifier potassium current and do not affect sodium transport through the membrane

lengthen the action potential

Question 9

what is a class 3 drug

Answer 9

Amiodarone, dronedarone, sotalol, dofetilide

lengthen action potential

Question 10

what are class 4 drugs

Answer 10

The non-dihydropyridine calcium channel blockers are particularly effective at slowing conduction at nodal tissue

Can help prevent attacks of junctional tachycardia (AVNRT and AVRT) and may control ventricular rates during paroxysms of other forms of SVT

Question 11

what is a class 4 drugs

Answer 11

calcium channel blockers eg Verapamil and diltiazem

reduce the plateau phase of action potential

Question 12

what is catheter ablation

Answer 12

frequency employed in the management of symptomatic tachyarrhythmias

Question 13

when should catheter ablation be used as first line therapy

Answer 13

symptomatic patients with a pre excited ECG because of accessory pathway conduction