Arrythmias 1

Question 1

Normal Electrocardiogram (ECG)
PQRST

1. Normal PR interval
2. Normal QRS complex
3. Normal QT interval

Answer 1

1. 0.12-0.2 sec
2. 0.04 - 0.14 sec
3. < 0.42 sec

Question 2

Ventricular AP : WHats the influx, whats the efflux?

Nodal Tissue : Whats influx, whats efflux?

Answer 2

1. Sodium influx, Potassium Efflux
2. Calcium influx, Potassium Efflux

Question 3

Abnormal Impulse Generation –Automatic Tachycardias

1. What can cause this?
2. If the rate of impulse generation from “latent” pacemaker cells is > rate of SA node, what starts?
3. What are some causes of Incr Phase 4 Slope?

Answer 3

1. Incr in phase 4 slope causing heightened automaticity of “latent” pacemaker cells
2. An arrhythmia
3. Digitalis, or catecholamines
   Hypoxemia
   Electrolyte imbalance (hypokalemia)
   Fiber stretch (Cardiac dilation)

Question 4

Abnormal Impulse Generation - Triggered Automaticity

Occur prior to phase 4 :
1) During repolarization (Early after depol , EADS)
-Caused by ? (3)

2) After repolarization (Delayed after depolarization , DADs)
-Caused by ? (2)

Answer 4

1. hypokalemia
   class 3 and 1a AAD’s
   -Slow stimulation rates
2. Digitalis or catecholamines
   -can be suppressed by Calc Channel Antags

Question 5

Name 4 ways that AAD’s can slow automatic Rhythms ?

Answer 5

1. Altering phase 4 slope
2. increasing threshold potential
3. Incr maximum diastolic potential
4. incr AP duration

Question 6

Class 1 AAD (1A, 1B, 1C)
1. Predom effect is to ?
2. Slows ___
3. How does each class affect the ventricular AP?

Answer 6

1. block the fast inward Na+ channels leading to a decr in the depolarization rate of phase 0
2. intra-cardiac conduction
3. 1a has moderate Na channel block, and prolonged repolarization
   -1b has mild Na channel block, and shortened repolarization
   -1c has MARKED Na channel block, and no change in repolarization

Question 7

Which drugs are in class 1A, 1 B and 1C?

Answer 7

1A : Disopyramide, Quinidine, Procainamide
1B : Lidocaine, Mexiletine
1C: Flecainide, Propafenone

Question 8

Class 1 A
1. Broad spectrum AAD meaning it can help with which 2 Arrhythmias ?
2. CLass Electrophys effects ?
-Widen ___
-Lengthen ____
-Lengthen ____
-No or slightly lengthen ___
3. Part of EP effects can be attributed to ?
4. ALL are effective in suppressing ?
5. In re-entrant tachycardias, they produce ?

Answer 8

1. Supraventricular and ventricular
2. QRS
   -QT interval (may induces TdP)
   -Refractory period
   - PR interval
3. K+ channel blockade
4. Automatic tachycardias
5. bidirectional block (by depressing conduction and prolonging refractoriness)

Question 9

Disopyramide :
1. Used to maintain ___ in ___ or __
2. Used to prevent recurrence of ___ or ___
3. Prolongs __ and ___
4.Prominent ___ action = AE’s
5. Signif AE’s ? (6)

Answer 9

1. Sinus rhythm, atrial flutter, fibrillation
2. ventricular tachycardias , fibrillation
3. QRS and QT interval
4. anticholinergic action
5. HYPOTENSION
   -ANTICHOLINERGIC SYNDROME (Dry mouth, constipation, urinary retention, precip glaucoma)
   -Gi upset
   -Hypoglycemia
   -PROARRHYTHMIAS (TdP )
   -HF (Depression of cardiac contracility)

Question 10

Quinidine
1. Maintains ___ in Afib or flutter and prevents recurrence of ?
2. Blocks ___ and multiple __
3. Prolongs ___, due to ?
4. Produces ___ and ___ **
5. AE’s (7)

Answer 10

1. sinus rhythm , ventricular tach or fibrillation
2. Na+ current, K+ currents
3. Cardiac AP duration, K+ blocking
4. Beta receptor blockade and vagal inhibition
5. Cinchonism (D/N/Tinnitus, Visual changes, dizzi, HA)
   -HYPOTENSION
   -THROMBOCYTOPENIA
   -Hemolytic anemia
   -QT INTERVAL PROLONG AND TDP
   -Proarrhythmia
   -DIARRHEA

Question 11

Procainamide
1. Used to treat ?
2. FOr acute tx? WHats no longer commerically available?
3. Procainamide (PA) and its Metab (NAPA)
-PA decreases ___, increases ___, slows __, and prolongs __ and ___
-NAPA lacks ___ but is equally potent in blocking ___

4. Why must you use in caution with HF pt’s with reduced EF?
5. Monitor PA and NAPA levels… wat are those levels?

Answer 11

1. SUPRA and ventricular arrhythmias
2. IV, PO version
3. automaticity
   -refractory periods
   -conduction
   -QRS and QT intervals
   -NA+ blockade, outward K+
4. Negative Inotrope
5. PA = 4-8 mcg/mL
   NAPA = 4-10 mcg/mL

Question 12

Procainamide :
1. Eliminated rapidly by ?
2. AE’s ? (7)

Answer 12

1. renal excretion , hepatic metabolism
2. HYPOTENSION (IV USE)
   -Nausea
   -TDP! Particularly with NAPA accum
   -LUPUS LIKE SYNDROME!!!!! (Test question) , this occurs more often and earlier during tx in “Slow acetylators”
   -Bone marrow aplasia
   -QT prolongation (less than quinidine)
   -Fever

Question 13

Class 1B : Lidocaine and Mexiletine

1. COnsiderably more effective for ?
2. Class EP effects
   -No effect on __ and ___
   -Decr in ___
   -No effect on ___
3. WHat accentuates its effects?
   -Changes in pH alter time that lidocaine is bound to ?
4. Attractive for which pt’s?

Answer 13

1. Ventricular arrhythmias
2. QRS, QT length
   - refractory period
   - PR interval
3. Acidosis
   - Na+ channel
4. Post -MI pt’s

Question 14

Lidocaine
1. Reduces ___ and alters ___
2. It’s not really effective as ___ only 15-20% effective in pt’s with ___
3. Minimal effects on __ or __

PK
1. How is it metabolized ?
2. What affects Vd and CL?
3. WHat causes reduced CL?
4. Therapeutic levels?

Answer 14

1. slope of Phase 4, threshold for excitability
2. monotherapy. Monomorphic VT
3. CO or BP
4. Liver metabolized
5. Heart failure
6. Hepatic disease
7. 1.5-5 mcg/mL

Question 15

Lidocaine AE’s

1. Levels > 5 mcg/mL
   C,S,D,D,V,M,P,N,T
2. Levels > 9mcg/mL
   P,S,R,S,B,C

Answer 15

1. Confusion
   slurred speech
   dizziness
   drowsiness
   vertigo
   muscle twitching
   perioral numbness
   Nausea
   tinnitus
2. Psychosis
   seizures
   respiratory suppression
   sinus arrest
   bradycardia
   complete heart block

Question 16

Mexiletine
1. oral analog of ?
2. Modifed to reduce __ allowing for ?
3. EP effects are?
4. Approved for treating ?
5. NOT EFFECTIVE FOR ?
6. Often used in combo with other AAD’s such as ?
7. AE’s (4) or 2 major ones

Answer 16

1. lidocaine
2. first pass metab, chronic oral therapy (F = 90%)
3. Similar to lidocaine
4. Ventric arrhythmias
5. atrial arrhythmias
6. Sotalol or quinidine to incr efficacy while limiting ae’s
7. CNS (Dizzi, tremor, ataxia, slurred speech, blurred vision , mem impairment, rarely psychosis or seizures)
   -Pro arrhythmia
   -GI upset
   -Thrombocytopenia (rare)

Question 17

Class 1C : Flecainide, Propafenone

1. Class EP effects?
   -Widen ___
   -Lengthens?
   -Decr?
   -Lengthens?
2. Profoundly slows __
3. Cannot be used in pt’s with ?!!!

Answer 17

1. QRS interval
   -QT interval (primarily via qrs widening)
   -Conduction velocity
   -PR interval
2. conduction velocity because of Slow association and dissociation with Na+ Channel
3. Structural heart disease (LVH, CHF, CAD , s/p MI and to a lesser extent heart valvular lesions)

Question 18

Flecainide (Tambocor)
1. Derivative of procainamide that does what?
2. Negative ___
3. effective for ?
4. CAUTION WHEN?
5. Currently used in ?
6. It profoundly slows ___
7. It blocks 3 currents (what r they)
8. In atrial tissue, What’s prolonged?
9. EP effects : Prolongs duration of ? (3)

Answer 18

1. Na+ channel blocker
2. Inotrope
3. BOTH supra and ventric arrhythmias
4. used for life threatening venrtric arrhythmias (Pro arrhytmic)
5. in absence of structural hd, for maintenance of sinus rhythm in supraventric arrhythmias (AFIB)
6. conduction velocity
7. Na+current, Delayed rectifier K+ current, and Ca2+ currents
8. AP duration prolonged at fast rates
9. PR, QRS, and QT

Question 19

Flecainide AE’s
1. P
2. B, D, L
3.n/v
4. Exacerbates ___ in pt’s with ___
5. __ in pt’s with pre existing conduction disease

Answer 19

1. Proarrhythmic
2. blurred vission , drowsiness, lightheadedness
3. heart failure, depressed LEFT ventric function
4. Heart block

Question 20

Propafenone

1. What channel blocker? some ___
2. Structurally similar to ? but has weaker ___
   -CI in ?
3. EP effects?
4. ECG effects?
5. Used primarily to maintain ??
6. How is it eliminated ?

Answer 20

1. Na+ channel blocker (Slow recovery)
   -Some K+ channel blocker
2. Beta blockers
   -Beta blocker activity
   -COPD or Asthma
3. Slows conduction in fast response tissues
4. prolongs PR and QRS duration
5. Sinus rhythm in pt’s with SUPRAventricular arrhythmias (AFIB)
6. Renal and hepatic (CYP2D6)

Question 21

Propafenone AE’s
-P
-Worsening ___
-B
-C
-G
-M
Propafenone would better charlie’s general mind

Answer 21

Proarrhythmia
-CHF
-Bronchospasm
-CNS effects (blurred vision, dizzi , pre syncope)
- GI upset
-Metallic bitter taste

Question 22

Class 2 AAD’s
1. Beta ADrenergic blocking agents like ?
2. Reduces inflow of ?
3. Increases AV nodal __ and prolongs AV nodal ___

4. ____ in AFIB or flutter
5. Class EP effects
   -No effect on ?
   -Incr ___On atrial and AV nodal tissues
   -Decr __
   -WIdened ___

Answer 22

1. Propanolol , esmolol, metoprolol, carvedilol, acebutolol
2. ca2+ into cell
3. conduction time, refractoriness
4. Ventricular RATE control
5. QRS or QT interval
   -Refractory period
   -Conduction velocity
   -PR interval

Question 23

Esmolol
1. Selective ?
2. What admin method?
3. Used primarily to ?
4. Dosing ? LD, MD, Rebolus

Answer 23

1. Beta 1 blocker
2. IV only
3. control ventric response in AFIB (rate control)
4. Loading dose 500 mcg/kg IV over 1 minute

– maintenance dose 50 mcg/kg/min to start and may increase by 50 mcg/kg/min every 4 minutes until a maximum of 300 mcg/kg/min

– may rebolus w/ 500 mcg/kg before each dose increase

Question 24

Class 3 : Name the 5 drugs

1. Delays repolarization by ?
2. Lengthens ___
   -Increases ___
   -Prolongs ____

Answer 24

Amiod, Dronedarone, Ibutilide, Dofetilide, Sotalol

1. blocking k+ channels
2. QT interval!!!
   -refractory period
   -cardiac AP

Question 25

Amiodarone 1. Metab where? via? 2. Elimination half life? 3. Inactivated ____ -Non selective ___ Blocks ___ Small degree of ? 4. Treats what ? 5. Maintains __ in AFIB 6. IV formulation good for ?

Answer 25

1. Liver, CYP3A4 2. 15-100 days 3. Na channel blocker (Fast on and off kinetics) - Beta blocking properties - K+ channels -Ca2+ antagonism decr Ca2+ current 4. Recurrent ventric Tachycardia or fibrillation resistant to other drugs 5. sinus rhythm 6. acute termination of ventric tachycardia and fibrillation

Question 26

Amiodarone : 1. THE GOOD - WHat kind of arrhythmias? -Efficacy? -May cause less ___ than sotalol -Ok for which pt's ? 2. The BAD -Oral amio has ? -Requires ___ -many potentially serious __ -Caution with what kind of allergy? 3. See chart for dose

Answer 26

1. Supra and ventric - > than other AADs -TDP -Post MI pt's or CHF pt's with LOW EF 2. SLOW ONSET OF ACTION - large total LD ( ~10 grams) -AE's -Iodine 3. See chart

Question 27

Amiodarone AE's 1. H 2. B 3. T 4. P 5. Hypo and Hyper ___ 6. Incr __ but rarely hepatitis 7. C 8. Dermatological rxns like (2) Her brother takes her puppy into college dorms

Answer 27

1. Hypotension (solvent used in IV ) 2. Bradycardia 3. TDP (optimize electrolytes) 4. Pulm FIBROSIS!!! 5. Thyroidism 6. LFTS 7. Corneal microdeposits 8. Photosensitivity -skin discoloration or blue grey skin

Question 28

Dronedarone 1. What form of amio? 2. Tx of Atrial Fib and Flutter -Maintains ___ 3. Less __ than amio 4. Less ___ than amio 5. What channels does it block? 6. COmmon ae's?

Answer 28

1. Non -iodinated 2. sinus rhythm 3. AE's 4. Effective 5. K, Na, and Ca2+ 6. V/D/N, Abd pain, ASthenia, prolonged QTC, acute liver injury

Question 29

Dronedarone 1. Metab by ? 2. Moderate inhib of ? 3. DOnt use in ? 4. Dont use in ? 5 Increased mortality in ? Severe -CI in ?? (2)

Answer 29

1. CYP 3a4 2. CYP3A, CYP2D6, AND PGP 3. PERM ATRIAL FIB OR FLUTTER 4. BRADYCARDIC PT"S (HR < 50 bpm, QTC > 500 ms, 2nd or 3rd degree Heart block) 5. Severe HF (CI in NYHA CLass IV, recent hospitalization within 30 days for decomp HF)

Question 30

Ibutilide 1. Blocks ? 2. Used to convert pt's from aflutter or afib to ? 3. Greater efficacy in ? 4. Effiacy is greater with ? 5. AE"s (5)

Answer 30

1. Delayed rect K+ current and inward Na+ current in some systems 2. Sinus rhythm 3. Aflutter 4. recent onset (days) vs prolonged presence (weeks) 5. AV and bundle branch blocks every kind of arrhythmia HA hypotension n/V

Question 31

1. Ibutilide DOSING ? 2. Terminate infusion at signs of? 3. Optimize __ and ___ prior to infusion 4. May cause ___ for up to 4 hrs post dose 5. Avoid which drugs 6 hrs after ?

Answer 31

-0.01 mg/kg IV over 10 minutes (weight < 60-kg) – 1 mg IV over 10 minutes (weight > 60-kg) – may repeat 10 minutes after END of the first infusion w/ additional equal dose Toxicity or success Potass and Magnesium TDP Class 1A or Class 3

Question 32

Dofetilide 1. Blocks ? 2. Used for maintenance of ___ in some1 who has undergone recent cardioversion and in pharm conversion of Afib or Aflutter to normal sinus rhythm 3. What closely correlates to serum conc? 4. Initiated in ? 5. DDi's ? (6) (very cool kids take piano music)

Answer 32

1. Delayed K+ rectifier current 2. SINUS RHYTHM 3. QT prolongation 4. hospital 5. verapamil, cimetidine, trimethoprim, ketoconazole,prochlorperazine, megestrol

Question 33

Dofetilide DOsing ? Requires? AE's? (7)

Answer 33

500 mcg PO twice daily (normal starting dose) -Renal and QTc interval dose adjust -headache – chest pain – dizziness – dyspnea – QT prolongation (and torsades de pointes (1-3%)) !!!!!! – AV and bundle branch block – ventricular tachycardia and fibrillation

Question 34

Sotalol 1. Non specific ___ 2. Primary action is prolonging cardiac AP by ? 3. Secondary action is ? 4. Used for both ? 5. QT interval ? 6. Monitor QT interval when ? 7. AE's ? (7)

Answer 34

1. Beta blocker 2. inhibiting delayed rect K+ channels 3. Non select B Blocker 4. Ventric tachyarrhythmias and AFIB or AFLUTTER 5. prolonged 6. 2-3 hrs after each dose during initiation or dose incr (3 day hospitalization for initiation) 7. increased QT interval – torsades de pointes (1.5-2%) – seems dose / concentration dependent – Bradycardia, fatigue, depression, bronchospasm, impotence!!!!!!!

Question 35

Sotalol Dosing See chart

Answer 35

See chart

Question 36

Channel IV AAD's 1. What do they block? WHat drugs 2. Useful in terminating ? 3. Class EP -Incr ___ -Decr __ -INCR __ -No effect on ___ 4. DOSING SEE CHART

Answer 36

1. CA2+ channel , NON DHP Verap and Diltiazem 2. re-entrant arrhythmias that involve the AV node and controlling the ventricular rate in atrial fibrillation or flutter 3. refractory period -conduction velocity -PR interval -QT or QRS intervals 4. See chart for dosing

Question 37

Misc Drugs : Adenosine 1. Activates ACetylcholine sensitive ___ in atrium and sinus and AV nodes resulting in ? (3) 2. 1st line agent for? (3) 3. It can unmask ___ 4. Can help differentiate between ? 5. AE"s?

Answer 37

1. K+ current -shortening of the AP – hyperpolarization – slowing of normal automaticity 2. terminating narrow complex PSVT – AV nodal reentry or AV reentry (such as WPW) – treating patients w/ a concealed accessory pathway 3. Atrial activity (AF or AFl) 4. VT or SVT 5. flushing, dyspnea, chest pain, ASYSTOLE, bronchospasms, abdominal discomfort

Question 38

Adenosine 1. Half life? 2. Dosing ? -What must be given immed after to ensure drug delivery to AV node prior to degradation ? 3. May repeat with ____ if No response 4. total acceptable dose is?

Answer 38

1. 10-30 secs ! 2. 6 mg IV push rapidly over 1-3 secs - 20-30 mL saline flush 3. 12 mg IV push in 1-2 mins --> if no response, can repeat AGAIN 4. 30 mg

Question 39

Digoxin 1. 2 primary uses? 2. ECG effects --> what does it lengthen? what does it do to ST seg?

Answer 39

1. inotropic effects in heart failure - vagotonic actions, yielding inhibition of Ca2+ currents in AV node and activation of acetylcholine mediated K + currents in atrium 2. PR lengthening - depression

Question 40

Digoxin 1. DDI's? 2. Serum conc in HF and in rate control -AFIB AFL ? 3. Managing toxicity includes ? (3) 4. DOsing see chart

Answer 40

1. PGP 2. 0.5-0.9 ng/mL 0.5-1.2 ng/mL 3. Atropine (minor), Magnesium, and or Digoxin immune fab (Ovine)

Question 41

Digoxin : 1. AE's -Arrhythmias ... What are the risk factors? -What are the 5 types of arrhythmias? -N -Disturbances of ? -Blurred or ___

Answer 41

1. Elevated digoxin levels, hypoxia, hypokalemia - DAD related tachycardias * sinus bradycardia * heart block * atrial tachycardia with AV block * ventricular bigeminy -Nausea -COgnitive function -yellow vision