Afib, AntiCoag, & NOAC reversal Flashcards
1
Q
intervals and rate of Afib
A
PR interval < 0.20 sec
atrial rate > 300bpm
2
Q
What is the most common arrhythmia in clinical practice?
A
A.Fib
increases with advancing age
⅓ of hospitalizations are caused by Afib
3
Q
Define Paroxysmal Afib
A
AF terminates spontaneously or with intervention within 7 days of onset
4
Q
Define Persistent Afib
A
AF lasts > 7 days
requires meds or electrocardioversion
-
Subcategory:
- long standing persistent: AF > 12 months
5
Q
Define Permanent Afib
A
Persistent AF + Pt & provider have made the decision to no longer try to have rhythm control
6
Q
Clinical Implications of AFib
A
- decreased diastolic filling → decreased cardiac output
- tachycardia -→ cardiomyopathy → decreased cardiac output
- blood stasis & atrial clot formation → thromboembolism → increased stroke risk
- ALL lead to INCREASED MORBIDITY & MORTALITY
7
Q
Indications for Cardioversion in AFib
A
- hemodynamic instability
- acutely altered mental status
- SBP <90 mmHG or s/sxs of shock
- ischemic chest discomfort
- acute HF
- 1st episode:
- symptomatic only (<65yo)
- NOT for asymptomatic elderly (>80 yo) + comorbidities
- Long-Term rhythm control
- Symptomatic Persistent AFib
- Failure of Rate control
- d/t persistent symptoms despite adequate rate control
- or inability to attain rate control
8
Q
Atrial Fibrillation Treatment Algorithm
A
No HF → PAID Fees: Propafenone, Amiodarone, Ibutilide, Dofetilide
HF → AID: Amiodarone, Ibutilide, Dofetilide
9
Q
Class II Vaughan-Williams Antiarrhythmic Agents
A
- Beta-adrenoreceptor antagonists: Esmolol, metoprolol, propanolol
- MOA: predominant action on the sinus node →affect Rate & Rhythm
10
Q
Class III Vaughan-Williams Antiarrhythmic Agents
A
Potassium blockers → widen the duration of the action potential
Rhythm
amiodarone, ibutilide, sotalol
11
Q
Class IV Vaughan-Williams Antiarrhythmic Agents
A
non-dihydropyridine CCBs → diltiazem, verapamil
predominant action on the AV node → affect Rate & rhythm
12
Q
Class Ia Vaughan-Williams Classification Antiarrhythmic Drugs and MOA
A
- Drugs: procainamide, quinidine, disopyramide
- MOA: Na+ channel blockade, prolonged repolarization → anti-arrhythmic not affecting rate
13
Q
Class Ib Vaughan-Williams Classification Antiarrhythmic Drugs and MOA
A
- Drugs: lidocaine, phenytoin
- MOA: Na+ channel blockade, shorten repolarization → antiarrhythmic that does not affect rate
14
Q
Class Ic Vaughan-Williams Classification Antiarrhythmic Drugs and MOA
A
- Drugs: Flecainide, Propafenone
- MOA: Na+ channel blockade, repolarization unchanged → antiarrhythmic that does not affect rate
15
Q
Procainamide (Pronestyl)
A
Class Ia antiarrhythmic→ Na channel blockade, prolong repolarization
- Indications: atrial & ventricular tachydysrhythmias
-
SEs:
- ventricular dysrhythmia
- agranulocytosis
- Systemic-Lupus erythematosus (SLE) -like syndrome
- Leukopenia, Maculopapular rash, flushing
- Torsades from QT prolongation
-
Contraindications:
- known hypersensitivity, heart block and SLE
16
Q
Quinidine (Quinidex)
A
Class 1a Antiarrhythmic→ Na+ channel blockade, prolong repolarization
- Indications: A.fib/flutter, life-threatening Ventricular arrhythmia, malaria
- Quinidine gluconate (IV or PO) and Quinidine Sulfate (PO/Tab only)
-
SEs:
- QT prolongation → torsades, AV block
- tremor, nervousness, photosensitivity
Black Box Warning: increased mortality in tx of non-life threatening arrhythmias; increase risk of structural heart disease
- DDI: lots of DDIs, will interact with drugs causing bradycardia or QT prolongation
17
Q
Disopyramide (Norpace)
A
Class 1a antiarrhythmic→ Na+ channel blockade, prolong repolarization
-
Indications: 1. Ventricular arrhythmias
- 2.A.fib conversion or prevention
-
SEs:
- Torsades, CHF,
- Agranulocytosis → just like procainamide
- Hypokalemia
Black Box Warning: increased mortality
- DDI: hypoglycemia, anticholinergic effects, 3A4 substrate
18
Q
Phenytoin
A
Class 1b antiarrhythmic → Na+ channel blockade, faster repolarization
-
Indications: atrial and ventricular tachhycysrhtymias caused by digitalis toxicity or long QT syndrome
- also seizure disorders
-
SEs:
- bradycardia, pancytopenia, hepatotoxicity, SJS
19
Q
Lidocaine
A
Class 1b antiarrhythmic → Na+ channel blockade, faster repolarization
-
Indications: used for ventricular arrhythmias only
- → raises the ventricular fibrillation threshold
-
SEs:
- twitching, convulsions, confusion, Respiratory arrest/depression
-
Contraindications:
- hypersensitivity
- Heart block
- Stokes-Adams Syndrome (fainting spell d/t arrhythmias)
- Wolff-Parkinson-White → tachycardia
20
Q
Flecainide (Tambocor)
A
Class 1c antiarrhythmics→ sodium channel blockade, no change in repolarization
-
Indications: used for SEVERE ventricular dysrhythmias
- can be used in afib, a.flutter, Wolff-Parkinson White, & SVT
- analogue of Procainamide
- Negative inotropic effects and depresses left ventricular function
-
SEs:
- QT prolongation, CHF, dyspnea etc
-
Contraindications:
- hypersensitivity, cardiogenic shock
- second or 3rd degree AV block
- dysrhythmias
21
Q
Beta-Blockers as Antiarrhythmics
A
reduce or block sympathetic NS stimulation → reducing transmission of impulses in the heart’s conduction system
affect Rate and Rhythm
-
Indication: myocardial depressant for both supraventricular dysrhythmias and ventricular dysrhythmias
- antianginal
- antihypertensive
- Drugs: esmolol, metoprolol, propranolol
22
Q
Amiodarone
A
Class III antiarrhythmic → K+ channel blockers, increase action potential duration
- MOA: blocks both the alpha and beta adrenergic receptors
-
indications: sustain V.tach, V.fib
- drug of choice for V. dysrhythmias according to ACLS
-
SEs:
- corneal deposits → visual halps
- photophobia, and dry eyes
- phototoxicity (uv light)
- pulmonary toxicity → pulmonary fibrosis
-
DDI:
- digoxin & warfarin (may have a delayed reaction)
-
Contraindication:
- hypersensitivity, severe sinus brady, Heart Block
23
Q
Diltiazem & Verapamil as Antiarrhythmics
A
- Class IV antiarrhythmics→ depress phase 4 of depolarization → affect RATE & rhythm
-
indications:
- paroxysmal supraventricular tachycardia
- rate control for atrial fib and flutter
-
Contraindications:
- Acute MI
- Pulmonary congestion
- Wolff-Parkinson white
- Severe Hypotension, cardiogenic shock
- sick sinus syndrome
- Heart Block
24
Q
General Antiarrhythmic SEs
A
- All antidysrhythmic can cause dysrhythmias
- hypersensitivity rxns
- N/V/D
- dizziness
- headache & blurred vision
- prolongation of the QT interval
-
DDI:
- warfarin (Coumadin): monitor INR
- Grapefruit Juice:
- amiodarone (III), disopyramide (1a), and quinidine (1a)
25
CHA2DS2-VASc
* **C**ongestive HF/LV dysfunction +1
* **H**ypertension +1
* **A**ge 65-74 +1
* **D**iabetes Mellitus +1
* **S**troke/TIA +2
* **V**ascular disease ( previous MI, PAD, aortic plaque): +1
* **A**ge ≥ 75 +2
* **S**ex category (female): +1
* +_Recommendations_:
* ≥ 2 for men = anticoag
* ≥ 3 for women = anticoag
26
General Anticoagulants
inhibit the clotting cascade, decrease fibrin formation
* Vitamin K antagonists
* Direct Thrombin Inhibitors
* Factor Xa inhibitors
27
When are Dabigatran (Direct thrombin inhibitor), Rivaroxaban (inhibit factor Xa), apixaban (inhibit factor Xa), or edoxaban (inhibit factor xa) preferred over warfarin?
for nonvalvular & non-cancer patients
28
When is low molecular weight heparin preferred over vitamin K antagonists, dabigatran, rivaroxaban, apixaban, or edoxaban?
for pts with **cancer-associated thrombosis**
29
When is **aspirin** recommended to prevent recurrent venous thromboembolism (VTE)?
for pts who stop anticoagulation therapy and do not have a contraindication to aspirin
30
Thrombolytic Therapy and pulmonary embolism
* generally not recommended in pts with acute PE
* it is preferred in selected patients with acute PE who have no hypotension and a low bleeding risk (grade 2c)
31
Warfarin (Coumadin): MOA, metabolism, & monitoring
vitamin K antagonist → affects factor II, VII, IX, X, and protein C & S → **takes 48-72 hours for this med to take effect**
* R & S enantiomers primarily metabolized by **CYP2C9**
* _Excretion_: primarily renal
* _Monitoring therapy_:
* narrow therapeutic window → use INR (monitors PT- prothrombin time)
32
Warfarin (Coumadin) Dosing
Recommended patient admin time is every evening
*
33
Warfarin and Disease State Interactions
34
What common food group can increase vitamin K and affect Warfarin?
**Green leafy vegetables**
→ counsel patients on the importance of a _CONSISTENT_ diet
35
Warfarin SEs
BLEEDING→ nosebleed, gum bleed, unexplained brusing, etc
* warfarin-induced skin necrosis
* Purple-toe syndrome
* **Teratogen (pregnancy category X)**
36
Dabigatran (Pradaxa)
* _MOA_: direct thrombin inhibitor (**Prodrug**)
* **NOT recommended in severe ESRD or those on hemodialysis**
* Do not require drug level monitoring but EXPENSIVE!
* _SEs_:
* GI sxs
* bleeding
* _Monitoring_: renal funx prior to initiation & at least annually
* _Important Pt info_:
* **do NOT open, chew, or break the capsule**
* \*\*\*store in the original package to protect from moisture\*\*\*
* better than warfarin for stroke or systemic embolism prevention
* AVOID in pts with Mechanical Heart Valves
37
Rivaroxaban (Xarelto)
* _MOA_: inhibits Factor Xa
* _metabolism_: by the liver
* _monitoring_: renal funx prior to initiation & at least annually
* Not better than warfarin for stroke or systemic embolism prevention
* AVOID in pts with Prosthetic Heart Valves
38
Apixaban (Eliquis)
* _MOA_: factor Xa inhibitor
* _metabolism_: liver
* _monitoring_: Renal funx prior to initiation & at least annually
* Better than warfarin for stroke or systemic embolism prevention
* **CAN** be used in **ESRD** patients on _hemodialysis_
* CYP3A4 substrate → monitor for DDIs
AVOID in pts with Prosthetic Heart Valves
39
Edoxaban (Savaysa)
* _MOA_: factor Xa inhibitor
* _Dosing_: CrCl **50 - 95** mL/min
* Pts with CrCl \> 95 mL/min: AVOID use – drug level too low
* AVOID in pts with Prosthetic Heart Valves
40
Black box warning for all NOAC agents
Dabigatran, Rivaroxaban, apixaban, edoxaban, betrixaban
**Premature d/c increases risk of thrombosis; spinal/epidural hematomas**
41
What is the reversal agent for Dabigatran (Pradaxa) overdose?
* Activated charcoal if used within 1-2 hours of ingestion
* dialysis: removes 62% at 2 hours; 68% at 4 hours
* **idarucizumab (Praxbind)** -
* humanized monoclonal antibody fragment
42
What is the reversal agent for factor Xa inhibitors
**Andexanet alfa** (**Andexanet)/(Andexxa)**
**reverses both** **Rivaroxaban & Apixaban**
during life threatening or uncontrolled bleeding
43
What is the reversal agent for warfarin?
Vitamin K
44
Andexxa Dosing (general), SEs, and **Black box warning**
* Dose based on rivaroxaban or apixaban dose
* _SEs_:
* infusion related rxns
* thromboembolic events
* bleeding
* cardiogenic shock, sudden death, CHF, acute respiratory failure
* **Black Box Warning**: Arterial & Venous thromboembolic events; ischemic events including MI and stroke; Cardiac Arrest; sudden death
45
Heparin vs LMWH
46
Fibrin Specific Thrombolytics
decrease systemic activation of **plasminogen** → prevent degradation of circulating fibrinogen
* do not have significant lytic action when exposed to fibrinogen with plasminogen
* **tissue plasminogen activator (t-PA) = Alteplase (recombinant t-PA)**
* **Reteplase (Retevase)**
* **Tenecteplase (TNKase)**
47
Non-Fibrin Specific Thrombolytics
cause **both fibrinolysis and _fibrinogenolysis_**
## Footnote
**Streptokinase**
**urokinase**
48
Alteplase (Activase)
Fibrin specific thrombolytics
* _indications_;
* acute MI, acute ischemic stroke, Acute PE
* _SEs_:
* **Bleeding (severe)**, **thromboembolism, cholesterol embolism, hypersensitivity rxn**
49
Reteplase (Retavase)
2nd gen recombinant t-PA from E.coli
* does not bind to fibrin as tightly as t-PA
* penetrates clots better
* dissolve clots faster
* **indications: STEMI**
* _Contraindications_:
* active bleeding
* recent stroke
* intracranial/spinal surgery within 3 months
* severe uncontrolled HTN
* _SEs_:
* bleeding, hypersensitivity (less than t-PA), cholesterol embolism
50
Tenecteplase (TNKase)
fibrin specific thrombolytics
* recombinant with modification of alteplase (from hamster ovary cells)
* _indication_: Acute MI
* _SEs_:
* bleeding, choelsterol embolism, arrhythmias (brady or tachy) → **antiarrhythmic tx be ready during TNKase tx**
* Anaphylaxis
* _Contraindications_:
* active internal bleeding
* hx of cerebrovascular accident
* intracranial/spinal surgery or trauma within 2 months
* severe uncontrolled HTN
