IE 3 Cardio Atrial Arrhythmias TSU

Atrial Fibrillation

• most common sustained cardiac arrhythmia

• irregular heartbeat where atria fail to contract rhythmically, causing blood pooling and clot formation

AFib symptoms

• racing heart

• fluttering

• palpitations

• SOB

• lightheadedness

• sometimes asymptomatich

normal heart rate

• determined by

• normal SA node pacing

• bradycardia

• tachycardia

• determined by

  • SA node

• normal SA node pacing

  • 60 - 100 bpm

• bradycardia

  • < 60 bpm

• tachycardia

  • > 100 bpm

• bradycardia

• supraventricular arrhythmias

• ventricular arrhythmias

• bradycardia

  • atrioventricular blocks

• supraventricular arrhythmias

  • atrial flutter

  • afib

  • supraventricular tachycardia

• ventricular arrhythmias

  • vfib

  • torsades de pointes

  • asystole

AV blocks: sx increase w/

severity

1st degree AV block

• impulse conducts slowed (partial block) at AV node for fixed interbal

• asymptomatic

• causes

  • AV nodal block (BB, non-DHP CCB, digoxin)

  • PNS stimulation

• EKG

  • PR > 0.2 secs

2nd degree AV block

• Mobitz Type 1

• Mobitz type 2

• Mobitz Type 1

  • conduction slows at AV node, then QRS fails to follow

  • decreased CO

  • asymptomatic

  • causes: AV node blockers, PNS stimulation

• Mobitz type 2

  • block is below AV node; atrial rate regular

  • symptomatic of bradycardia

  • unpredictable

3rd degree heart block

• complete heart block

• AV dissociation

• no P waves

• symptomatic due to bradycardia

• need permanent pacemaker to control ventricular rate

Paroxysmal Supraventricular Tachycardia (PSVT)

• sudden, rapid firing of SVT automaticity focus

• 150 - 250 bpm

PSVT

• nonpharm

• pharm

• radiofrequency ablation

• nonpharm

  • mild to mod = vagal techniques (massage, valsalva, ice water immersion

  • severe (syncope, angina, HF) = direct current cardioversion (DCC)

• pharm

  • increase vagal tone = digoxin

  • decrease conduction thru Ca tissue = adenosine, BB, non-DHP CCB

  • depress conduction thru Na tissue = Quinidine, Procainamide,

• radiofrequency ablation

  • destroy accessory pathway

  • replaces need for anti-arrhythmic therapy

causes of AF and Aflutter

• re-entry

  • AF = multiple reentrant loops

  • Aflutter = single dominant reentrant wavelet

• structural heart disease

  • MI, valvular HD, congenital abnormalities

• high adrenergic states

  • thyrotoxicosis, surgery, alcohol, withdrawal, sepsis

• other pathways

  • HTN, CAD, obesity, etc

EKG finding Afib

• many atrial foci firing at rapid rates (350 - 450 bpm)

• irregularly irregular w/ no p waves

EKG finding Aflutter

• atrial impulses faster than SA node impulses (220 - 350 bpm)

• single ectopic focus

• sawtooth

• regular rhythm

• occur less frequently than Afib

presentation/symtpoms Afib and Aflutter

• fatigue, palpitations, SOB, hypotension, syncope, chest pain

• AF w/ RVR (HR > 100 bpm)

• can be asymptomatic

AF Classification

• paroxysmal

  • terminates spontaneously or w/ intervention within 7 days of onset

• persistent

  • continuous sustained AF > 7 days

• longstanding persistent

  • continuous AF sustained > 12 months

• permanent

  • no attempts to restore/maintain sinus rhythm

• nonvalvular AF

  • AF in absence of rheumatic mitral stenosis, mechanical heart valve, mitral valve repair

• thrombus clot forms in atrium due to

• highest risk for clot formation is

• most common thromboembolic event is

• blood pooling

• left atrial appendage (LAA)

• ischemic stroke

CHA2DS2-VASc Score

• purpose

• components (points)

• maximum points

• interpretation

• purpose

  • calculate stroke risk and determine need for anticoagulation in AF pts

• components (points)

  • 1 point

    • congestive heart failure/LV dysfunction

    • HTN

    • diabetes

    • vascular disease (prev MI, PAD, aortic plaque

    • age 65 - 74 years old

    • female

  • 2 points

    • age ≥ 75 years old

    • stroke/TIA/thromboembolism

• maximum points

  • 9 points

• interpretation

  • higher score = higher stroke risk w/o anticoagulation

HAS-BLED Bleeding Risk Assessment

• purpose

• components (points)

• interpretation

• purpose

  • identify pts at high risk of bleeding on anticoagulation

• components (points)

  • HTN = 1 point

  • abnormal renal/liver function = 1 or 2 points

  • stroke = 1 point

  • labile INR = 1 point

  • elderly (≥ 65) = 1 point

  • drugs or alcohol = 1 or 2 points

• interpretation

  • score ≥ 3 = high bleeding risk

CHAD2DS2-VASc score = 0 (men) or 1 (women)

no anticoagulation needed

CHAD2DS2-VASc score = 1 (men) or 2 (women)

anticoagulation therapy may be considered

CHAD2DS2-VASc score = ≥ 2 (men) or ≥ 3 (women)

oral anticoagulation recommended

• warfarin (target INR = 2 - 3) or DOACs

• DOACs preferred except in cases of mitral stenosis or mechanical heart valves

Warfarin (Coumadin)

• 1 - 10 mg daily

• no P-gp substrate

• dose adjustment based on INR

DOACs

• preferred over warfarin

• superior or non-inferior efficacy and safety

• bridging not required unless clot confirmed

DOACs: Dabigatran (Pradaxa)

• class

• dosing

• renal adjusment

• interactions

• class

  • DTI

• dosing

  • AF and PE dosing: 150 mg PO BID

• renal adjustment

  • CrCl 15 - 30 ml/min → 75 mg PO BID

• interactions

  • P-gp substrate

  • reduce dose/avoid w/ 3A4/P-gp inhibitors and inducers

DOACs: Rivaroxaban (Xarelto)

• class

• dosing

• renal adjustment

• interactions

• class

  • factor Xa

• dosing

  • AF = 20 mg Po daily with food

  • VTE = 15 mg PO BID x 3 weeks, then 20 mg PO daily

• renal adjustment

  • CrCl15 - 30 ml/min → 15 mg PO daily w/ food

• interactions → avoid inhibitors and inducers

  • CYP3A4/5

  • P-gp substrate

DOACs: Apixaban (Eliquis)

• class

• dosing

• renal adjustment

• interactions

• class

  • factor Xa

• dosing

  • AF = 5 mg POBID

  • VTE = 10 mg PO BID x 1 week, then 5 mg PO BID

• renal adjustment

  • 2.5 mg PO BID if 2 of 3 criteria met:

    • over 80 years old

    • < 60 kg

    • Scr ≥ 1.5 mg/dL

• interactions

  • CYP3A4, p-gp → avoid inducers and inhibitors

DOACs: Edoxaban (Sayvaysa)

• class

• dosing

• interactions

• class

  • factor Xa

• dosing

  • AF and VTE = 60 mg PO daily

• interactions

  • avoid Rifampin (inducer)

rate control strategy

• goals

  • symptom control, increase ventricular filling time

  • 100 110 bpm at rest

• meds

  • BBs

  • non-DHP CCBs

  • digoxin

BBs

• 1st line

• preferred for

  • HF w/ low EF: carvidolol, metoprolol, bisoprolol

  • CAD

non-DHP CCBs

• diltiazem, verapamil

• if BB use is limited

digoxin (Lanoxin)

• indication

• MOA

• effect

• dosing

• PK

• therapeutic index

• s/sx of toxicity

• indication

  • systolic HF,

  • hypotension

  • sedentary pts

• MOA

  • bind to Na-K-ATPase

  • positive inotrope

  • negative chronotrope

• effect

  • slow HR at rest only

• dosing

  • 0.125 - 0.5 mg daily

• PK

  • renally excreted

• narrow therapeutic index

  • HF = 0.5 - 0.8 ng/ml

  • arrhythmia = < 1.2 ng/ml

  • toxicity risk = > 2ng/ml

• s/sx of toxicity

  • anorexia

  • n/v/d

  • yellow halos

  • HAs

  • PVC

  • AV block

  • vtach, vfib

acute managment of AF w/ RVR: hemodynamically unstable

direct current cardioversion

acute managment of AF w/ RVR: hemodynamically stable

meds based on underlying conditions

• no decompensated HF → IV non-DHP CCBs, IV BB, IV digoxin, IV amiodarone

• decompensated HF → IV amiodarone, digoxin

ryhthm control

• meds

• catheter ablation

• surgery

rhythm control strategy

• goal

• cardioversion

• goal

• cardioversion

  • restore and maintain sinus rythm

  • direct current cardioversion

  • pharm cardioversion

  • post cardioversion

• direct current cardioversion (DCCV)

• pharm cardioversion

• post cardioversion

• electrical shock - efficacy 80 - 90%

• meds - efficacy 40 - 60%

• require AADs to maintain NSR

DCCV

• emergent indication

• elective indication

• emergent

  • hemodynamically unstable

• elective

  • rate control ineffective

  • younger pts (< 60)

  • poor exercise

anticoagulation for cardioversion

• risk

• visual

• TE seen

• post cardioversion

• risk

  • TE risk if AF duration > 2 days (or unknown)

• visual

  • Transeoesophageal echo (TEE) > TTE

• TE seen

  • therapeutic anticoagulation needed for at least 3 weeks before cardioversion

• post cardioversion

  • anticoagulant for at least 4 weeks after cardioversion

AADs for Pharmacological Cardioversion: drugs (proven efficacy)

• amiodarone (Cardarone, Pacerone)

• dofetilide (Tikosyn)

• ibutilide (IV only)

• flecainide

• propafenone

AADs: Normal LV function, no prior MI or structural HD

• amiodarone, ibutilide

• procainamide

AADs: prior MI or structural HD

-amiodarone

dofetilide

AADs for Maintenance of NSR

• amiodarone, dronedarone, dofetilide, Sotalol, flecainide, propafenone

• depends on underlyinh structural HD, renal function, toxicities

Amiodarone (Cordarone, Pacerone)

• MOA

• PK

• efficacy

• toxicity

• DDIs

• MOA

  • class 3, activity from all 4 classes

  • prolong QT, refractoriness, slow HR, AV node conduction, intracardiac conduction

• PK

  • long t ½ = 60 days

• efficacy

  • most effective

• toxicity

  • most toxic → pulmonary fibrosis, thyroid dysfunction, blue-gray, etc

• DDIs

  • extensive die to CYP inhibition and P-gp inhibition

Dronedarone (Multaq)

• MOA

• PK

• ADR

• BBW

• MOA

  • class 3, activity from all 4 classes

• PK

  • less lipophilic

  • shorter t ½

• ADR

  • not as much as amiodarone

• BBW

  • increased risk of death w/ decompensated HF or permanent HF

Sotalol (Betapace AF)

• MOA

• use

• precautions

• monitoring

• CI

• MOA

  • class 3, non-selective BB

• use

  • not for HTN or rate control

• precautions

  • avoid in systolic HF

• monitoring

  • renal function, QT porlongation

• CI

  • QT interval > 450 msec

dofetilide (Tikoysn)

• MOA

• risk

• intitiation

• use

• monitoring

• DDIs

• MOA

  • class 3

• risk

  • torsades de pointes

• intitiation

  • prev rquired hospitalization for 1st 5 doses

• use

  • cardioversion

  • maintanence of NSR

• monitoring

  • renal function

  • QT interval

  • drug interactions

• DDIs

  • QT-prolonging drugs

Flecainide (Tambocor) and Propafenone (Ryhtmol)

• MOA

• CI

• clinical pearl

• MOA

  • class 1 agents

• CI

  • structural heart disease

• clinical pearl

  • pill in pocket

catheter ablation

• pulmonary vein isolation

• AV node ablation

• indications

• pulmonary vein isolation

  • can be curative for AF symptoms

• AV node ablation

  • leads to permanent pacemaker

• indications

  • AAD ineffective, CI, intolerant

  • 1st line in younger pts