Anti-arrhythmics Flashcards

1
Q

Drugs that ↓ firing rate of pacemakers:

A

-CCB: ↑phase 0 threshold\

-NaCB: ↓phase 4 slope

-BetaB:
↓phase 4 slope
↑phase 0 threshold
↑action potential duration
↑maximum diastolic potential

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2
Q

Drugs that ↓ conduction velocity through the AVN:

A

-CCB: slow impulse propagation

-BetaB

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3
Q

Drugs that ↓ conduction velocity through the atria & ventricles:

A

-NaCB: slow impulse propagation

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4
Q

Drugs that ↑ refractory period:

A

-KCB
-CCB
-BetaB

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5
Q

K channel blockers

A

Increase QT directly without affecting heart rate
↑QT ↔ RR ↑QTc

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6
Q

Beta blockers & Ca channel blockers

A

Increase QT indirectly by slowing heart rate ↑QT ↑RR ↔ QTc

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7
Q

Arrhythmias: Classification

A
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8
Q

Arrhythmias: Treatment strategies

A
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9
Q

Effects of Antiarrhythmic Drugs

A
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10
Q

Antiarrhythmic drugs have a _____ therapeutic index

A

narrow

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11
Q

Rate vs Rhythm Control

A
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12
Q

Beta Blockers and Ca Channel Blockers: Properties

A
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13
Q

Sodium Channel Blockers: Classes

A
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14
Q

Class IA sodium channel blockers

A

MOA:
– Moderate binding to Na channels = ↑QRS interval
– Also block K channels = ↑action potential duration (APD)
– Also block ACh = anti-cholinergic effects

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15
Q

Class IB sodium channel blockers

A

MOA:
– Weak binding to Na channels = ↔ QRS interval
– ↓action potential duration (APD)

Uses:
– Ventricular arrhythmias only

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16
Q

Class IC sodium channel blockers

A

MOA:
– Strong binding to Na channels = ↑↑↑ QRS interval
– ↔ action potential duration (APD)
– May also ↑PR interval, ↓contractility

Uses:
– Ventricular & supraventricular arrhythmias
– Most common = AF/AFL
– Increased mortality in patients with CHF and CAD

17
Q

Pneumonic for NaCB Classes

A
18
Q

Potassium Channel Blockers

A
  • MOA:
    – ↑APD, refractoriness
  • Most important thing to remember:
    – ↑QTc = risk of Torsades de Pointes
19
Q

Importance of Rate Control

A
20
Q

Amiodarone

A
21
Q

Digoxin

A
22
Q

Adenosine

A
  • “Class V” antiarrhythmic drug
  • Uses:
    – Acute treatment of PSVT
    – Diagnostically as a coronary vasodilator
    – IV only

MOA
– Binds adenosine A1 receptors in SAN/AVN
* SAN: ↓ Firing rate
* AVN: ↓↓↓↓ Conduction velocity

Effect
– When given as a fast IV bolus, halts AVN conduction

23
Q

Clinical Impact: K and NA Blockers

A