Arrhythmias

Front 1

Basic cause of rhythm disturbance

Back 1

1. automaticity (impulse generation)
2. conduction
3. combined

Front 2

AHA classification of rhythms based on

Back 2

1. Rate
2. QRS width
3. Regularity
4. Stable vs. unstable

Front 3

General approach

Back 3

-treat the pt not the EKG!
-acute vs chronic
-stable vs unstable
-usually more worrisome with
1. ischemia
2. LV dysfunction
3. other structural disease

Front 4

methods of treatment

Back 4

1. mechanical: thump (massage)
2. external electrical: defibrillator, pacing
3. ablative procedures
4. implantable devices: AICD, pacers

Front 5

paddle placement - standard

Back 5

“Sternal”: just to the right of the upper sternal border, below the clavicle
“Apex”: Left MAL, nipple level

Front 6

paddle placement - alternative

Back 6

“Sternal”:posterior, right infrascapular
“Apex”: Anterior, over left precordium

Front 7

AICD

Back 7

-The pulse generator is usually placed in a subcutaneous pocket in the pectoral region. It contains a header with ports for leads, the battery and capacitors, memory chips, integrated circuits and microprocessors, and the telemetry module.
-The transvenous right ventricular lead contains the shock coils and pacing electrodes. Additional leads may be connected for right atrial or left ventricular pacing.

Front 8

vaughan-williams Class I agents (Na blockers)

Back 8

IA:
Quinidine
Procainamide
Disopyramide
IB:
Lidocaine
Tocainide
Mexilitene
IC:
Flecanide
Propafenone

Front 9

drugs

Back 9

slide 20, 21

Front 10

rhythms with a pulse

Back 10

1. bradycardias
2. tachycardias
3. superimposed "unusual beatS"

Front 11

rhythms without a pulse

Back 11

1. pulseless VT/VF
2. PEA
3. asystole

Front 12

Bradycardias

Back 12

-sinus bradycardia
-AV blocks:
Low grade: 1st degree, 2nd degree type 1
High grade: 2nd degree type II, 3rd degree

Front 13

AV blocks

Back 13

-1st degree (P - R > .20 seconds)
-2nd degree Type I (progressive P-R, then dropped QRS; reset)
-2nd degree type II: dropped QRS; no warning
-3rd degree: regular P-P, R-R but unrelated

Front 14

bradycardia algorithm

Back 14

slide 27

Front 15

bradycardia- poor perfusion- what to do

Back 15

1. prepare for percutaneous pacing without delay for high degree block
2. Atropine .5mg to max 3 mg
3. prepare for transvenous pacing

Front 16

tachycardias

Back 16

1. sinus tachy
2. atrial fib/flutter
3. other narrow-complex tachycardias
4. wide-complex tachycardias
5. ventricular tachycardias

Front 17

tachycardia algorithm

Back 17

slide 29

Front 18

people become unstable with tachycardia when HR becomes...

Back 18

>150

Front 19

tachy- pts that are unstable- what to do

Back 19

1. perform immediate synchronized cardioversion
-est IV access and give sedation if pt conscious
-if pulseless arrest develops, see pulseless arrest algorithm

Front 20

synchronized cardioversion

Back 20

-used to interrupt reentry circuits
-more organized rhythms often respond to lower energies
1. aflutter and PSVT 50-100 J
2. afib, monomorphic V.tach 100 J
3. polymorphic V.tach 200 J

Front 21

proarrhythmias

Back 21

-serious arrhthymias generated by anti-arrhythmic agents
-most are tachy-arrhythmias
-majority of these involve Torsade De pointes
-all antiarrhythmics have some proarrhythmic effect
-use of multiple drugs compounds effects (brady, hypotension, torsade)
-cardioversion usually preferable to adding a second drug

Front 22

depressed LV function

Back 22

-many antiarrhytmics depress ventricular function leading to CHF
-Amiodarone and Lidocaine have least depressive effects
-Amiodarone has broad antiarrhythmic spectrum and less negative inotropic effect, and has moved into more prominent role

Front 23

narrow QRS tachycardias

Back 23

-< .12 sec
-implied origin at or above the AV node
-reg. vs. irreg (a. flutter, a. fib, MAT)

Front 24

Afib/ flutter

Back 24

Flutter: single abnml reentry circuit in atria. Sawtooth "F" or flutter waves ~300/min
Fibrillation: chaotic circuitous firing of atria ~400/min. Wavy, undulating baseline. "Irregularly irregular"

Front 25

afib epidemiology

Back 25

-most common rhythm disturbance
-~75% of pts are >65 yo
-assoc conditions:
1. HTN
2. ischemic dz
3. CHF
4. rheumatic heart dz
-inc risk of strok, CHF, death

Front 26

afib predisposing factors

Back 26

1. electrophysiological abnormalities
2. atrial pressure elevations
3. atrial ischemia
4. inflamm or infiltrative atrial dz
5. drugs: alcohol, caffeine
6. hyperthyroidism
7. changes in autonomic tone
8. postoperative
9. neurogenic
10. idiopathic

Front 27

afib presentations

Back 27

1. Paroxysmal AF: self-terminating episodes with duration < 7 days,
2. Persistent AF: requiring pharmacologic or electrical cardioversion to convert to sinus rhythm
3. Permanent AF: unable to maintain sinus rhythm.
Symptoms: range from asymptomatic to cardiovascular collapse and stroke

Front 28

afib- eval

Back 28

1. pt clinically unstable?
2. cardiac function impaire?
3. WPW present?
4. durations <48 or >48 hrs

Front 29

Eval of afib1

Back 29

1. H&P
2. EKG
3. Blood tests: thyroid, renal, hepatic
4, Transthoracic echo

Front 30

mgmt of pts with afib

Back 30

-requires knwoledge of: pattern, underlying conditions
-decisions about:
-Restoration/maintenance of sinus rhythm
-control of the ventricular rate: diltiazem or beta blockers!!
-antithrombotic therapy

Front 31

classifications of reccomendations

Back 31

Class I
Procedure/treatment SHOULD be performed/administered
Class IIa
It is REASONABLE to perform procedure/administer treatment
Class IIb
Procedure/treatment MAY BE CONSIDERED
Class III
Procedure/treatment SHOULD NOT be performed/administered, since it is not helpful, and may be harmful

Front 32

Newly discovered AF

Back 32

-not always clear whether this is the first episode
-if it is paroxysmal --> no therapy unless they become symptomatic; anticoag?
-if persistent -->
accept permanent -> anticoag
rate control and anticoag -> consider antiarrythmics -> cardioversion

Front 33

recurrent paroxysmal AF

Back 33

-minimal or no sx --> anticoag as needed --> no drug for prevention
-disabling sx --> anticoag and rate control as needed --> AAD therapy ---> AF ablation if AAD tx fails

Front 34

slide 60

Back 34

60

Front 35

amiodarone

Back 35

-all 4 vaughn williams class effects
-150 mg over 10 min
-1mg/min x 6hrs
-0.5 mg/min x 18 hrs
-max daily dose 2g

Front 36

electrical cardioversion

Back 36

-an initial energy of 200 J or greater is recommended
-Anticoagulation is recommended for 3 wk prior to and 4 wk after cardioversion for patients with AF of unknown duration or with AF for longer than 48 h

Front 37

Sinus tachycardia (narrow QRS tachy)

Back 37

-a cause of sx or a result of underlying disease?
-treat the cause, if able: pain, fever, anxiety, volume
-if causing sx, bblockers may be indicated

Front 38

other narrow QRS tachycardias treatments

Back 38

-vagal maneuvers
-adenosine 6 mg rapid IV push
-adenosine 12 mg rapid IV push x 2
-conversion: probable rentry SVT

Front 39

reentry supraventricular tachycardia (SVT, PSVT)

Back 39

-regular, narrow QRS @ 160-220/min
-no discernible P waves, but may be obscured at this rate, so can't clearly identify site
-paroxysmal if comes and goes

Front 40

narrow QRS tachycardias- does not convert

Back 40

-Aflutter
-ectopic AT
-junctional

control the rate!- diltiazem, B blockers

Front 41

Regular Stable wide QRS tachycardias- V tach or uncertain

Back 41

-amiodarone
-cardioversion
-procainamide
-sotalol

Front 42

regular stable wide QRS tachy- SVT with BBB

Back 42

-adenosine

Front 43

wide complex tachycardias

Back 43

-attempt to distinguish from SVT with aberrancy
-initial provider wrong ?50%
-Dx VT as aberrant SVT
-many feel adenosine is overused in WCT, esp in Lidocaine- resistant VT
-lead to delay in tx

Front 44

VT vs. SVT with aberrancy

Back 44

VT:
-hx of CAD
-other structural heart dz
-AV dissociation

SVT w/aberrancy:
-prev hx aberrant rhythms
-accessory pathways
-preexisting/rate-dependent BBB

Front 45

irregular stable wide QRS tachycardias

Back 45

-A. fib with BBB
-A. fib + WPW
1. NO AV nodal blocking agents!
2. amiodarone ?
-Torsade

Front 46

torsade de pointes

Back 46

-varying amplitude of QRS, precipitated by increased QT interval
-stop QT prolonging drugs
-correct electrolytes
-MgSO4 1-2gms IV over 5-60 min, then infusion over 1 hr
-pacing, isoprel?

Front 47

Premature complexes: PACs/PJCs

Back 47

-stop smoking/stimulants
-if need Rx --> quinidine, verapamil, bblockers

Front 48

PVCs

Back 48

-occasional beats WNL
-frequency and complexity have no prognostic significance for pts withouth structural heart dz
-with MI > 10 PVCs/hr or complex PVC have inc mortality, esp if depressed LV function
-Rx: primarily for sx
1. bblockers
2. lidocaine (lethal if this is a ventricular escape rhythm)
3. catheter ablation

Front 49

Escape complexes

Back 49

-occur after sinus pause
-same key features of site as premature complexes

Front 50

pre-excitation syndromes (WPW)

Back 50

-accesory pathway bypases delay at AV node
-PR <.12 sec
-slurred upstroke QRS
-QRS >.12

Front 51

rhythms without a pulse

Back 51

1. pulseless VT
2. V fib
3. PEA
4. asystole

Front 52

V.fib/Vtach without a pulse

Back 52

1. 1 shock followed by immediate CPR (5 cycleS)
-minimize interruption of CPR
-biphasic defibrillators convert ~90% with first shock!
2. energies in adults
-monophasic: 360
3. second shock same or higher resume CPR

Front 53

V.fib/Vtach without a pulse cont

Back 53

4. Vasopressors (one or the other)
-Epinephrine 1mg q 3-5 min
-vasopressin 40 U IV/IO
5. third shock same or higher; resume CPR
6. antiarrhythmics
-amiodarone
-lidocaine
-magnesium
7 start at top

Front 54

Asystole/PEA

Back 54

1. CPR
2. Vasopressors
-epinephrine 1 mg q 3-5 min
-vasopressin 40 U IV/IO
3. consider atropine; resume CPR

Front 55

post-resuscitation care

Back 55

-optimize tissue perfusion, esp for the brain
-maintain appropriate: BP, HR, Ventilation, Temp
-identify precipipating cause of arrest
-prevent recurrence of arrest