Antiarrythmics

Question 1

K effects

Answer 1

Hyperkalemia shortens AP duration, dec pacemaker rate

Hypokalemia prolongs AP duration, inc pacemaker rate

Question 2

Class Ia

Answer 2

Inc QRS and QT
Procainamide and Quinidine
Open Na > inactive
Small K blocker, anti-M effects
Phase 3 in ventricle -> prolonged QT -> proarrythmic

Question 3

Supraventricular tachyarrythmias

Answer 3

Want to dec AV nodal conduction so ventricles can do their thing

Question 4

Class 1b

Answer 4

Dec QT and ERP
Inactivated > open
Ventricular tissue slower to repolarize

Question 5

Lidocaine

Answer 5

Class Ib

Toxicity: confusion, dizziness, paresthesia, intractable seizures

Question 6

Class Ic

Answer 6

Inc QRS, small inc in QT
Flecainide

Not red

Question 7

Class II

Answer 7

Reduces AV nodal conduction -> dec automaticity and reentry
Dec amount of Ca released from SR -> negative inotropism
Beta 1 and 2
ECG: potential for AV block

Question 8

Class III

Answer 8

Amiodarone and Ibutilide
May inc PR interval, prolong QT interval
Amiodarone: smurf skin, inhibits 3A4, contraindicated in iodine ax -> All the Blockers and dec resistance via alpha, beta, Ca block

Question 9

Class IV

Answer 9

Potential AV block

Question 10

Dihydropyridine

Answer 10

-ipines
Reflex inc HR
Block Ca in contractile cells
Class IV

Question 11

Non-dihydropyridine

Answer 11

Verapamil, Diltiazem
Block Ca in contractile and automatic cells (dec HR)
Brake the heart
Class IV

Question 12

Adenosine

Answer 12

Can ppt bronchoconstriction

Question 13

Digoxin

Answer 13

Na/K ATPase blocker -> inc vagal tone
Slows AV nodal conduction
Can be used to control ventricular rate in AFwith acute heart failure
HYPOKALEMIA AMPLIFIES EFFECT OF DIGOXIN

Question 14

Bradyarrythmia

Answer 14

AV block