Cardio: Anti-Arrythmics

Question 1

What parts of the heart has fast APs?

Answer 1

Cardiomyocytes and Purkinje fibers

Question 2

What parts of the heart has slow APs?

Answer 2

SA and AV nodes

Question 3

What are the class 1a anti-arrhythmics?

Answer 3

Quinidine
Procainamide
Disopyramide

Question 4

MOA of class 1a anti-arrhythmics?

Answer 4

Block sodium channels, and have some K+ channel affect as well.
-will prolong QT and QRS due to this

Question 5

what effect do the class 1a anti-arrhythmics have on the heart AP?

Answer 5

Reduce slope of phase 0=Prolong QRS complex

Prolong AP duration=prolong QT interval

Question 6

Indication for procainamide?

Answer 6

Effective in sustained V-tach and arrythmias after MI

Question 7

Adverse effects of procainamide?

Answer 7

QT prolongation=Torsades!

Drug induced lupus

• arthralgias, pleuritis, hepatitis, fever
• anti-histone Ab

Question 8

is quinidine used much clinically?

Answer 8

Nope.

Not sure why we even learn it then??

Question 9

Adverse effects of quinidine?

Answer 9

QT Prolongation=torsades due to K+

Cinchonism
-hearing loss, tinnitus, confusion, delirium

thrombocytopenia

GI Upset

Question 10

Indication for Disopyramide?

Answer 10

Recurrent ventricular arrhythmias

Question 11

Adverse effects of Disopyramide

Answer 11

QT Prolongation=Torsades

Negative inotrope=heart failure

Atropine like symptoms
-blind as a bat, mad as a hatter, dry as a bone

Question 12

What are the class 1B anti-arrhythmics?

Answer 12

Mexitile (oral) and Lidocaine (IV)

Question 13

What effect do class 1B anti-arrhythmics have on AP?

Answer 13

Shorten AP

DO NOT PROLONG QT like 1A

Question 14

Clinical use of lidocaine?

Answer 14

Termination of V-tach after MI

Question 15

Adverse effects of lidocaine?

Answer 15

Least toxic of all class 1

hypotension

Neurological side effects
-paresthesias, tremor, slurred speech

Question 16

Clinical use of Mexiletine

Answer 16

Ventricular arrythmias after MI

Question 17

Adverse effects of Mexiletine

Answer 17

Neurological side effects

-paresthesias, tremor, slurred speech

Question 18

Do class 1C drugs prolong the QT interval?

Answer 18

Nope, just the QRS complex as they are pure Na+ blockers

-no K+ activity

Question 19

what are the Class 1c anti-arrhythmic drugs?

Answer 19

Flecainide and propanefone

Question 20

Would you use class 1c anti-arrhythmic drugs post MI?

Answer 20

Nope, they are only for healthy hearts

Question 21

Clinical use of flecainide and Propafenone?

Answer 21

Both: SVTs

Only flecainide: refractory ventricular arrythmias that are life threatening

Question 22

Class II anti-arrhythmic drug MOA?

Answer 22

B-blockers

• reduce cAMP to reduce contractility
• block the funny current to prevent calcium from entering
• -reduces HR

Question 23

Class II anti-arrhythmic effects on AP?

Answer 23

Slow HR via SA node, so they prolong the RR interval

Reduce AV Conductance, so prolong PR interval

Question 24

Clinical use for Propranolol

Answer 24

Arrhythmias associated w stress and thyroid storm

A fib and A Flutter, PSVTs, and post-MI arrhythmias

Question 25

Which of the B-blockers is short acting?

Answer 25

Esmolol | -great for IV ifusion for rapid onset and termination

Question 26

Clinical use for esmolol?

Answer 26

SVTs, thyrotoxicosis, post-MI arrhythmias Used as adjunct w general anesthesias to control arrhythmias peri-operatively

Question 27

Adverse effects of B-blockers?

Answer 27

Block B2, so: - reduced CO, reduced glucose metabolism - increased LDL, low HDL - sedation - withdrawl sydrome

Question 28

Contraindications of B-blockers?

Answer 28

Asthma, PVD, Raynauds, T1DM, bradycardia

Question 29

MOA of class 3 anti-arrhythmic drugs?

Answer 29

Block K+ channel

Question 30

What are the class 3 anti-arrhythmic drugs?

Answer 30

amiodarone, sotalol, ibutilide/Dofetilide

Question 31

Effects of class 3 anti-arrhythmic drugs on AP?

Answer 31

Prolong AP, QT interval, and ERP

Question 32

Clinical use of Amiodarone?

Answer 32

Recurrent V-tach and a-fib

Question 33

Adverse effects of Amiodarone?

Answer 33

AV block and bradycardia Fatal pulmonary fibrosis** Photodermatitis and deposits in corneas Blocks thyroid=hyper/hypothyroidism -iodine

Question 34

Which of the class 3 drugs has B Blockers activity as well?

Answer 34

Sotalol

Question 35

Clinical use of Sotalol

Answer 35

Life threatening Ventricular arrhythmias Maintenance of sinus rhythm in patients w a fib

Question 36

Side effects of sotalol

Answer 36

Depressed cardiac function QT torsades

Question 37

Clinical use of ibutilide/dofetilide?

Answer 37

Restore sinus rhythm in a fib and maintain sinus rhythm after cardioversion in those w a fib

Question 38

Adverse effects of ibutilide/dofetilide?

Answer 38

QT prolongation and increase risk for ventricular arrhythmias

Question 39

What are the class 4 anti-arrhythmics?

Answer 39

Verapamil, Dilitiazem

Question 40

MOA of class 4 anti-arrhythmics?

Answer 40

block L-type calcium channels | -slow SA node depolarization

Question 41

What effect do class 4 anti-arrhythmics have on AP?

Answer 41

Prolong ERP and PR interval

Question 42

Clinical use of Verapamil, Dilitiazem?

Answer 42

Termination of PVST and ventricular rate control in a fib and flutter

Question 43

Adverse effects of Verapamil, Dilitiazem?

Answer 43

Negative inotropy, AV block, SA arrest, bradycardia Constipation and gingival hyperplasia (verapamil only)

Question 44

MOA of adenosine?

Answer 44

Activates A1 receptor on Gi-coupled GPCR -enhances K+ efflux and inhibits Ca2+ influx Causes marked hyperpolarization, slowing AP

Question 45

Effect of adenosine on AP?

Answer 45

Prolongs QT interval and ERP

Question 46

Indication of adenosine?

Answer 46

PVST conversion to sinus rhythm

Question 47

Adverse effects of Adenosine?

Answer 47

SOB, bronchospasm, chest burning, flushing, AV block

Question 48

What is a proarrhythmia? What can cause it?

Answer 48

A proarrythmia is a drug induced new arrhythmia or worsening of an existing arrhythmia -Flexainide can cause this

Question 49

What are the non-pharm options to treating arrhythmias?

Answer 49

Catheter ablation Implantable defibrillator Artificial pacemaker Direct current cardioversion

Question 50

Which drug classes cause torsades?

Answer 50

Class 1A and Class 3 | -slide 44

Question 51

Which drug classes can cause excessive slowing of the heart and lead to persistent V-tach

Answer 51

Class 1A and 1C | -slide 44

Question 52

Drugs to control rhythm in A-fib?

Answer 52

Class 1C drugs: reduce retrograde conductance Flecainide and propanefone Class 3 drugs: terminate reentry by prolonging refractory period -amiodarone, sotalol, ibutilide/Dofetilide

Question 53

If a patient has a-fib with HF, what drug classes can you use?

Answer 53

Class 3 only | -1C contra in unhealthy hearts!

Question 54

If a person has A-fib w/o HF, what drug classes can you use?

Answer 54

Class 1C or 3

Question 55

Pharmological Rate control in A-fib if person has HF?

Answer 55

B-blocker

Question 56

Pharmological Rate control in A-fib if person w/o HF?

Answer 56

CBB or B-blocker

Question 57

Will you need to do anti-thrombotic therapy in someone with A-fib?

Answer 57

Yes, most of the time it is needed!

Question 58

PSVT non-pharm treatment?

Answer 58

Vagal maneuvers

Question 59

What is the preferred treatment in PSVT?

Answer 59

Vagal maneuvers->Adenosine is first

Question 60

To prevent PVST episodes, what is first line?

Answer 60

Verapamil and Diltiazem

Question 61

What drugs can cause torsades?

Answer 61

1a and 3, as well as hydroxychloroquine and azithromycin | -stop them, and torsades will stop

Question 62

If pt is hemodynamically unstable with torsades, how would you treat?

Answer 62

Direct current cardioversion

Question 63

If pt is hemodynamically stable with torsades, how would you treat?

Answer 63

correct electrolyte imbalance, MgSO4, may need pacemaker