Anti-arrhythmic drugs: Vfib, Bradycardia, Cardiac arrest

Question 1

What is cardiac arrest?

Answer 1

Cessation of cardiac mechanical activity (pulseless, unresponsive, apneic)

Question 2

Half of cardiac arrests happen where?

Answer 2

Outside of the hospital (in public, witnessed or non-witnessed)

Question 3

Survival rates of cardiac arrest?

Answer 3

Low, higher w/ witnessed arrest (7-8%)

Question 4

Hospital survival rates of cardiac arrest?

Answer 4

Higher due to rapid response, defibrillation, if shockable rhythm

Question 5

What are the most common etiologies in adult arrest?

Answer 5

VFib and pulseless Vtach
(typically ischemic heart disease, blood is fully oxygenated at arrest)

Question 6

What are the most common etiologies in pediatric arrest?

Answer 6

Pulseless electrical activity (PEA) and asystole
(typically acute respiratory failure, asphyxiation, patient is typically hypoxemic/hypotensive)

Question 7

Which drugs affect phase 0 of the cardiac cycle (Na+ inward flow/depolarozation)?

Answer 7

Na+ channel blockers
Strong: Flecainide, Propafenone
Moderate: Quinidine, Procainimide, Mexiletine
Weak: Lidocaine, Phenytoin

Question 8

Which drugs affect phase 2 of the cardiac cycle (Ca2+ inward flow, K+ outward flow, Plateau phase)?

Answer 8

CCBs: Verapamil, Diltiazem

Question 9

Which drugs affect phase 3 of the cardiac cycle (K+ outward flow, Ca2+ starts to close, Rapid repolarization)?

Answer 9

K+ channel blockers: Amiodarone, Sotalol

Also Dofetilide, Dronedarone

Question 10

Which drugs affect phase 4 of the cardiac cycle (resting potential)?

Answer 10

BBs: Propanolol, Metoprolol, Atenolol, Esmolol

Question 11

What are relatively stable tachycardias?

Answer 11

Sinus tachy, AV-nodal re-entry SVT

Question 12

Are relatively stable tachycardias easier to manage with rate control?

Answer 12

Yes

Question 13

How to manage patient with symptomatic tachycardia that is unstable?

Answer 13

Synchronized cardioversion

Question 14

How to manage patient with acute symptomatic tachycardia that is stable?

Answer 14

Determine if QRS is wide or narrow
If narrow: (<120) w/ regular ventricular rhythm –>Adenosine is drug of choice, if failure to respond –> BB (IV esmolol, PO metoprolol or atenolol) or CCB (Non-DHPs)

Question 15

Avoid Adenosine in what kind of tachycardia?

Answer 15

Unstable (narrow or wide) or irregular

Question 16

How to manage a stable patient with symptomatic tachycardia w/ narrow complex, A-fib, SVT, or sinus tachy w/ irregular ventricular rhythm (usually A-fib)?

Answer 16

General: focus on control of rapid ventricular rate (BB or CCB preferred), goal HR <110bpm

Question 17

How to manage an unstable patient with symptomatic tachycardia w/ narrow complex (A-fib, SVT, or sinus tachy) w/ irregular ventricular rhythm?

Answer 17

Cardioversion preferred (can be electrical or pharmacologic)

Question 18

If A-fib is present for more than 48 hours (time is takes for a clot to form), what is the patient at risk for?

Answer 18

Cardioembolic event, get TEE to rule out emboli

Question 19

Which BBs are B-1 selective?

Answer 19

Esmolol, Metoprolol, Atenolol

Question 20

What are beta-blocker blues?

Answer 20

Fatigue/depression that may occur as a result of BB therapy

Question 21

What are the unstable tachycardias?

Answer 21

Wide-complex monomorphic VT, Torsades de pointes

Question 22

How are unstable tachycardias managed?

Answer 22

Carefully managed w/ multiple agents including antiarrhythmetics

Question 23

Symptomatic tachycardias with a wide complex (>120ms) are usually what?

Answer 23

Ventricular arrhythmias

Question 24

Which medications can be used in V-tach with regular rhythm?

Answer 24

-Adenosine first line (ONLY IF REGULAR RATE), avoid if unstable/irregular!!!
-Procainamide, Amiodarone, or Sotalol (If QTc is <500)

Question 25

Which is the risk of V-tach with irregular rhythm and QTc >500 ?

Answer 25

Usually can turn into Torsades

Question 26

How to manage V-tach with irregular rhythm and unstable vitals?

Answer 26

Immediate defibrillation

Question 27

Treatment of V-tach with irregular rhythm and QTc >500 that turns into Torsades?

Answer 27

Magnesium sulfate bolus (trying to correct electrolytes and stabilize action potential)

Question 28

What meds should be withdrawn in V-tach w/ irregular rhythm if QTc >500?

Answer 28

Any QT-prolonging meds: -Antiarrhythmics (class I & III) outside of Amiodarone *assess for drugs that can increase conc. of antiarrhythmetics -Antifungals: Fluconazole -Macrolides: Erythromycin -Quinolones: Levofloxacin -Antipsychotics: Haldol, Ziprasidone -Anti-nausea: Droperidol, Promethazine

Question 29

How can digoxin be dangerous?

Answer 29

Narrow therapeutic window, can cause toxicity easily

Question 30

Which BBs are non-specific, and can be dangerous with athsma?

Answer 30

Natolol, Propanolol

Question 31

What is QTc prolongation?

Answer 31

Delayed repolarization of the ventricles, heart takes longer to contract/relax

Question 32

Goal of Adenosine bolus?

Answer 32

Trying to get patient back to NSR

Question 33

Usually an irregular ventricular rhythm w/ a narrow complex is caused by what?

Answer 33

A-fib

Question 34

Usually an irregular ventricular rhythm w/ a narrow complex is caused by what?

Answer 34

A-fib

Question 35

Procainamide is what class of antiarrhythmetic?

Answer 35

Class Ia

Question 36

MOA of Procainamide?

Answer 36

Includes blockade of Na+ channels of the heart muscle

Question 37

Procainamide adjustment for geriatric population?

Answer 37

None, use adult dosing

Question 38

Renal and Hepatic adjustments for Procainamide?

Answer 38

None

Question 39

ROA of Procainamide?

Answer 39

IV bolus over 30-60 min

Question 40

Side effects of Procainamide?

Answer 40

Diarrhea, loss of strength/energy, vomiting, hypotension, dizziness, fatigue

Question 41

Every antiarrhythmetic can cause QTc prolongation, with the exception of what medication?

Answer 41

Amiodarone

Question 42

How does amiodarone bring the body back to NSR?

Answer 42

Extending the next repolarization

Question 43

Can Sotalol be used in acute renal failure?

Answer 43

NO

Question 44

VFib and Pulseless VT have a better survival and less comorbidity with what?

Answer 44

Early CPR and defibrillation

Question 45

During AED preparation for Vfib and pulseless VTach, what should be ongoing?

Answer 45

CPR

Question 46

After 2 minutes of compressions in Vfib and pulseless Vtach, check what?

Answer 46

Rhythm and pulse

Question 47

What can improve survival of out-of-hospital VF and pulseless VT?

Answer 47

AED

Question 48

Can an airway be established without interrupting compressions in VFib/Pulseless Vtach?

Answer 48

Yes

Question 49

1st line pharmacotherapy for VF/Pulseless VT?

Answer 49

Epinephrine IV (after CPR/defibrillation shock 1 and 2 and CPR)

Question 50

MOA of Epinephrine?

Answer 50

Potent alpha-1 & beta-1 agonist

Question 51

What is a second agent that can be added to a shockable rhythm after the administration of cpr/defib/epi if needed?

Answer 51

Amiodarone IV

Question 52

What is bradycardia?

Answer 52

Symptomatic patient with HR <50bpm

Question 53

How to manage bradycardia?

Answer 53

Treat underlying cause, establish airway, IV access -identify hypotension, mental status changes, cardiovascular collapse

Question 54

Medication for bradycardia?

Answer 54

Treat w/ Atropine (if ineffective, then administer dopamine or epinephrine)

Question 55

MOA of Atropine?

Answer 55

Antagonist, muscarinic R blocker (blocks parasympathetic pathway which is inhibitory) causes excitatory event --> raises HR

Question 56

MOA of Dopamine?

Answer 56

Mixed alpha/beta agonist w/ D1 R agonist *stimulates HR and force of contraction (has some vasoconstriction)

Question 57

Usually an irregular ventricular rhythm w/ a narrow complex is caused by what?

Answer 57

A-fib

Question 58

Most common drug that induces bradycardia?

Answer 58

Beta blockers

Question 59

If the patient has v-tach with regular rhythm and a QTc >500 what is the drug of choice?

Answer 59

Amiodarone (risk of torsades is low w this drug)

Question 60

Treatment for chronic nonsustained (intermittent) VT that is asymptomatic?

Answer 60

No tx required (unless post-MI or rHF - give BB)

Question 61

1st treatment for chronic nonsustained (intermittent) VT that is symptomatic?

Answer 61

Beta Blocker

Question 62

2nd line treatment for chronic nonsustained (intermittent) VT that is symptomatic (if BB does not work)?

Answer 62

Non-dihydropyridine CCB **ONLY IF NO STRUCTURAL HEART DZ (MI or rHF)

Question 63

What to add to therapy for chronic nonsustained (intermittent) VT that is symptomatic despite BB or Non-DHP CCB?

Answer 63

Antiarrhythmetic therapy MC: Amiodarone, Flecainide, Propafenone, Sotalol

Question 64

If the patient has HFrEF, what is the preferred antiarrhythmetic for VT?

Answer 64

Amiodarone (in addition to standard HFrEF therapy)

Question 65

If the patient has Chronic kidney disease, what med do we have to be cautious with ?

Answer 65

Sotalol: dosing must be reduced

Question 66

If the patient has QTc prolongation, which meds should be avoided?

Answer 66

Avoid antiarrhythmetics in QTc >500ms **EXCEPT FOR AMIODARONE

Question 67

If an antiarrhythmetic is added to an ACS event, what may happen?

Answer 67

Can have poor outcomes (increase mortality) If HAVE TO USE antiarrhythmetic: use amiodarone

Question 68

Although most antiarrhythmetics can be used for ventricular and atrial arrhythmias, which two drugs are used for A-fib ONLY?

Answer 68

Dofetilide, Dronedarone **NOT TO BE USED IN VENTRICULAR ARRHYTHMIAS