Arrhythmia 2 Flashcards
Quinindine = Class 1a
3 therapeutic uses?
Side Effects?
Metabolism?
Therapy
1) A-Fib
2) Brugada’s Syndrome
3) Short QTS syndrome
Side Effects
1) Pro-arrhythmia
2) Nausea/Diarrhea
hepatic metabolism
Quinindine = Class 1a
What 3 channels does Quinindine block? What effect does this have on the AP?
Quinindine –> block I-Na, I-K, I-to –> prolong QRS –> prolonged AP duration
Procainamide = Class 1a
What is the MoA for the parent compound? What about the metabolite?
What is it’s effect on the SAN and AVN?
Parent compound:
Na chnl blocker –> prolong QRS
Metabolite:
K chnl blocker –> increase AP duration
Suppresses SAN, AVN
Procainamide = Class 1a
What are it’s 2 therapeutic uses?
What side effect is associated with the oral form?
Therapy
1) acute treatment of atrial/ventricular arryhthmia
2) pre-excited A-Fib
Oral form –> Lupus
Disopyramide = Class 1a
MoA?
Treatment? (2)
A good choice for what patients?
MoA
–Na chnl blocker with vagolytic, anticholinergic effects
Treatment
1) vagal-mediated A-Fib
2) some VT
Good choice for patients with slow baseline HR
Disopyramide = Class 1a
Side Effects?
Urinary retention
Blurred vision
Worsened glaucoma
What are the two Class 1b anti-arrhythmics?
What is their MoA?
Class 1b
–Lidocaine, Mexiletine
MoA: block Na chnls, especially inactivated
What Class 1b drug is the treatment of choice for ischemia-related arrhythmia?
What are the side effects as related to proarrhythmia and neurological?
Lidocaine
Side Effects
Proarrhythmia: SAN arrest, impaired conduction
Neuro: tremor, paresthesia, seizure
What Class 1b drug is a form of oral lidocaine and has GI side effects that can be reduced by taking it with meals?
Treatment?
Mexiletine
Treatment: VT (in combo with QT prolonging meds)
What are the two Class 1c drugs, which are the most potent Na chnl blockers?
What do they treat, and in what kind of patients?
Class 1c
–Flecainide, Propafenone
Therapy
–atrial tach + v-tach in structurally normal hearts with preserved LV function
What are the side effects of the Class 1c drugs, Flecainide and Propafenone?
Flecainide is contraindicated in what patients that have what QRS interval?
Class 1c: Flecainide, Propafenone
Side Effects
- -depress LV function (worsen HF)
- -proarrhythmia in ischemic tissues
Flecainide contraindicated in patients with structurally abnormal heart; QRS > 120ms
In general, Na chnl blockers work best @ what kind of HR?
What about K chnl blockers?
Na chnl blocker: high HR
K chnl blocker: slow HR
How are beta blockers antiarrhythmogenic?
What are the 3 BBs used?
2 side effects?
They increase the refractory period of the A/V node.
Metoprolol, Atenolol, Nadolol
Side Effects
–bronchospasm, bradycardia
How do class III antiarrhythmics work?
How do they affect the action potential?
What is the major risk of class III drugs?
Class III drugs are K channel (IKr) blockers.
Increase AP duration and the refractory period (QT prolongation)
Thus, they cause a risk of Torsades de pointes.
What is special about sotalol?
What tests need to be performed while a patient is on sotalol?
Sotalol is also a non-specific beta blocker.
Serum K, Mg, and renal function should be closely followed.
What are the two therapeutic uses for Amiodarone?
How does its potency compare to other class III drugs?
Therapy: atrial and ventricular tachyarrhythmias.
It is more potent than Sotalol.
Why does Amiodarone have a ton of side effects?
Iodine-based medication
What is Dronedarone and how does it differ from Amiodarone?
When is it contraindicated?
Milder version of amiodarone that does not contain iodine. It is less effective and less toxic (non-toxic to the lungs and thyroid).
Contraindicated in HF
What is a concern when starting a patient on Ibutalide or Dofetilide?
Both have a chance of creating an arrhythmia (Torsades de pointes) with onset of medication. Therefore, patients need to be kept in the hospital for monitoring.
What is the MoA for Dofetilide, and what part of the heart is it selective for?
Dofetilide
Highly selective I-Kr blocker, selective @ atria
Name the four class 3 anti-arrhythmics.
Class 3
1) Amiodarone
2) Dronedarone
3) Sotalol
4) Dofetilide
(+ Ibutilide)
What type of Ca chnls to the Class 4 anti-arrhythmics block, and how do they affect the SAN/AVN?
What are they used to treat?
Which one is a negative inotrope, and can cause sinus arrest, hypotension, and AV block?
L type Ca Chnl Blocker –> slow conduction time, increase refractory period @ SAN, AVN
SVT
Verapamil is a negative inotrope.
How does Adenosine affect the K current? What is it used to treat?
Activates K current
SVT
What classes are used to treat sinus tachycardia?
Class II, IV
