anti arrhythmic

Question 1

phase 0

Answer 1

• Depolarization via Na
• Atrial contraction begins
o SA node depolarization of myocytes
o Rapid Na depolar then inactivate rapidly

Question 2

phase 1

Answer 2

• Slight repolarization
• K channels
o Transient rapid repolarization of myoctye

Question 3

phase 2

Answer 3

• Platuea slow Ca
• Relaxation
o Inc intracellular calcium causes contraction of muscles
o Muscles begin to relax

Question 4

phase 3

Answer 4

• Repolarization via K channels
• Relaxation complete
o Delayed rectifier K channels open and repolarize completely

Question 5

phase 4

Answer 5

• Resting state
o Gradients of Na/K are restored by Na/K pump
o Na channels now return to resting state

Question 6

PR

Answer 6

Atrial depolarization

Question 7

QRS

Answer 7

ventricular depolarization

Question 8

QT

Answer 8

ventricular repolarization

Question 9

non pharm

Answer 9

• Implanted defribillators
• Implanted pacemakers
• External defribillation
• Radiofrequency ablation via catheter

Question 10

class 1 Na blocker

Answer 10

quinidine

lidocaine

Question 11

class 2 B blocker

Answer 11

• Propranolol

* Esmolol

Question 12

class 3 K blocker

Answer 12

amiodarone ((has class 1A characteristics and class 2)
dronedarone
sotalol (class 2 characteristics)
dofetilide (pure K blocker)

Question 13

Class 4 Ca blocker

Answer 13

• Effective for re-entry Arr, used as prophylaxis
• AVOIDED in ventricular arrhythmias
o Verapamil- prototype
o Diltiazem- eff antiArr
o Nifedipine is not as eff antiArr b/c of compensatory effect from vasodilator action

Question 14

types of arrhythmia

Answer 14

• Atrial flutter
• Atrial fibrillation
• Atrioventricular nodal re-entry
• Premature ventricular beats
• Ventricular tachycardia
• Ventricular fibrillation

Question 15

concern for dentist

Answer 15

• Orthostatic hypotension
• History of arrhythmia
• Hypertension
• MAKE SURE to consult with cardiologist about using EPI or other Vasoconstrictor
• Saliva related with antimuscarinc activity
• Drug int. with metabolism of codeine
• Quinidine can cause oral hemorrhaging and petechial
• Lidocaine as antiarrhythmic has additive effect on LA

Question 16

quinidine

Answer 16

affect all myocytes

Question 17

lidocaine

Answer 17

act on ischemic myocytes

Question 18

amiodarone

Answer 18

o high potential for toxicity, res. to other tx

o microcrystalline deposits in cornea and skin, thyroid hormone, parasthesias, tremor, and pulmonary fibrosis

Question 19

dronedarone

Answer 19

o less toxic analong of amiodarone

Question 20

sotalol

Answer 20

o chiral compound, one isomer is beta blocker, both work as anti arr

Question 21

dofetilide

Answer 21

o	torsades de pointes
o	headaches and dizziness
o	Drug int.
♣	Prolong QTc
⎥	Quinolone (ciprofloxacin, moxifoxacin)
♣	Inhibitors of CYP 3A4
⎥	Macrolide Ab (clarithromycin, erythromycin)