SHOCK THE VT/ VF PATIENT 1 11/7/2017 SHOCK Is the Unstable - - PDF document

11/7/2017 1

Common Heart Rhythms in the Hospital

Gregory M Marcus, MD, MAS Associate Professor of Medicine Division of Cardiology University of California, San Francisc

Disclosures

• Research Support: NIH, PCORI,

Medtronic, Cardiogram

• Consulting: InCarda, Johnson & Johnson,

Lifewatch

• Equity: InCarda

Goals of the Talk

• What to do when encountering an

arrhythmia

• Leveraging the encounter to maximize

benefit to the patient long-term

Tachyarrhythmias- Unstable

SVT Atrial fibrillation AF with WPW VT/ VF

• Unconscious, altered mental status,
• ngoing chest pain
• “Hypotension” is a clinical judgment

SHOCK THE PATIENT

11/7/2017 2

Anything other than VF MAKE SURE IT IS ON “SYNCH”

SHOCK THE PATIENT

Unstable SVT, AF, VT “Is the defibrillator

• n synch?”

SHOCK THE PATIENT STILL in unstable SVT, AF, VT SHOCK THE PATIENT “Is the defibrillator

• n synch?”

Tachyarrhythmias-quasi-stable

Atrial fibrillation SVT AF with WPW VT

Tachyarrhythmias-quasi-stable

Atrial Fibrillation

Nondihydropyrdine Calcium channel blockers Diltiazem Verapamil Beta-blockers Metoprolol Atenolol Carvedilol Labetolol Propanolol

Blood Pressure

• 1. Address underlying condition
• 2. Esmolol
• 3. Digoxin
• 4. Amiodarone
• 5. ?Dronaderone?

11/7/2017 3 How about cardioversion?

• DC cardioversion is the most efficacious but requires sedation
• If the patient has no structural heart disease (no CAD, normal

EF, not severe LVH) 200-300 mg of flecainide or 600 mg of propafenone (MUST BE GIVEN WITH AV NODAL BLOCKER DUE RISK OF 1:1 ATRIAL FLUTTER)

• Ibutilide IV- Torsades risk, requires 4 hours of monitoring
• Tikosyn (dofetilide) can work, but usually in 1-2 days and

generally in setting of careful QT monitoring over 3 days Elective Cardioversion

46 year old man without cardiovascular risk factors and symptomatic AF on propafenone 46 year old man without cardiovascular risk factors and symptomatic AF on propafenone

• A SLOWER FLUTTER PARADOXICALLY

CAN RESULT IN A FASTER RHYTHM BECAUSE THE AV NODE CAN ACCOMMODATE A GREATER PROPORTION OF DEPOLARIZATIONS

• PATIENTS ON FLECAINIDE OR

PROPAFENONE REALLY SHOULD BE ON AN AV NODAL BLOCKER

How about cardioversion?

• Most thrombi in atrial fibrillation arise from the left atrial

appendage

• Cardioversion can reduce left atrial appendage function

– Even from AF to sinus

• The pericardioversion period is a particularly pro-

thrombotic time

– Regardless of mode: DC/ electrical, pharmacologic, spontaneous Elective Cardioversion

11/7/2017 4 I decide to go with

• Prior to cardioversion:1, 2

– Can exclude preexisitng

thrombus by TEE – Can anticoagulate (therapeutic/ for at least 3 weeks) prior to cardioversion

1. JACC 2006;48:e149-246 2. Chest 2004;126:429S-456

Elective Cardioversion

I decide to go with

• During and after cardioversion:1, 2

– Anticoagulation for at least 4 weeks

– Applies even to those who would otherwise not require anticoagulation

• Generally does not make sense to cardiovert

AF in order to avoid anticoagulation

1. JACC 2006;48:e149-246 2. Chest 2004;126:429S-456

Elective Cardioversion

I decide to go with

• The magic 48 hours

– Must be documented! – Reason to consider starting anticoagulation NOW in the hospital as it may “stop the clock” – There are cases of stroke even within this time window, so

• nly do this if you need to and start anticoagulation if you can

Elective Cardioversion

Bigger Picture on AF THREE GOALS IN TREATING AF IN GENERAL

• 1. We want to prevent THROMBOEMBOLISM
• 2. We want to avoid fast ventricular rates over

a long period of time to prevent ventricular myopathy

• 3. We want to improve quality of life

11/7/2017 5

Bigger Picture on AF THREE GOALS IN TREATING AF IN GENERAL

1.We want to prevent THROMBOEMBOLISM

We want to prevent THROMBOEMBOLISM

• 1. Atrial fibrillation increases the risk of stroke

5 times

• 2. 23.5% of all strokes in those age 80-89 are

attributed to AF How do we know this? From clinically recognized atrial fibrillation.

Wolf et al. Stroke 1991

ATRIAL FIBRILLATION IS OFTEN ASYMPTOMAIC

Page et al. Circulation 1994

Audience Response Question Among Cryptogenic Stroke Patients, AF can be found in:

• 0-3%
• 3-10%
• 10-20%
• 20-30%

11/7/2017 6

AF is common if you look hard enough among cryptogenic stroke patients

Brachman et al. Circ A&E 2016

We want to prevent THROMBOEMBOLISM

Atrial fibrillation is association with a 30%-40% increased risk of dementia

Atrial Fibrillation Predicts a Higher Risk of MI

11/7/2017 7

Atrial Fibrillation is associated with a higher risk of kidney disease How is This Relevant to Hospital Medicine?

• That patient who develops atrial fibrillation in

the setting of cellulitis or pneumonia

• ASSUME YOU WERE LUCKY TO CATCH IT

BECAUSE THE PATIENT WAS BEING MONITORED

• ANTICOAGULTE UNLESS THERE IS A

COMPELLING REASON NOT TO

–Examples: »CHADSVASC of 0 or perhaps 1 »History of hemorrhagic stroke

Gialdini et al. JAMA 2014

11/7/2017 8

“A patient never calls you in the middle of the night to thank you for not having a stroke.”

• Michael Ezekowitz, M.B., Ch.B., D.Phil

What if I have a suspicion for AF but we don’t catch it?

• Can order a Zio patch (monitors for 1-2

weeks)

Injectable Loop Recorder

11/7/2017 9

Atrial fibrillation ablation

• Elective, generally takes time to schedule
• For SYMPTOMATIC AF- not stroke prevention
• Empiric (target PV isolation)
• Efficacy ~70% in PAF and ~50% in persistent AF at 1

year, attrition in many over time

• Can have early recurrence with long-term success

Audience Response Question The success of a typical atrial flutter ablation is:

• 40-50%
• 50-70%
• 70-95%
• 95-100%

Atrial FLUTTER ablation

• Quicker procedure, easier to schedule
• We have a very clear target
• Flutter tends to be more difficult to rate control
• Antiarrhythmic drugs do not work so well for flutter
• Ablation of atrial flutter is FIRST LINE
• Success rate is ~97%

Tachyarrhythmias-quasi-stable

SVT

11/7/2017 10

Tachyarrhythmias-quasi-stable

SVT

Vagal Manuevers

WA WAIT! GET A 12 LEAD GET A 12 LEAD ECG! ECG!

Tachyarrhythmias-quasi-stable

SVT

Vagal Manuevers

• Carotid sinus massage
• Valsava
• Will terminate ~20%1
• 1. Lim SH et al. Ann Emerg Med 1998;31:30-35

Tachyarrhythmias-quasi-stable

SVT

Adenosine

• Metabolized by red blood

cells and endothelium

• Give 6 mg IV with 20 cc flush
• Repeat with 12 mg IV X 2
• How do I know if I’ve given

enough?

75% reduction in ED visits among those undergoing catheter ablation (p=0.003).

11/7/2017 11

Tachyarrhythmias-quasi-stable The most likely diagnosis is:

• 1. Ventricular Tachycardia
• 2. Atrial fibrillation with WPW
• 3. SVT with aberrancy

Tachyarrhythmias-quasi-stable Tachyarrhythmias-quasi-stable

Atrial Fibrillation with preexcitation

AV nodal blockers

Give:

Procainamide Ibutilide Then refer to EP for ablation

11/7/2017 12

Tachyarrhythmias-quasi-stable

Ventricular Tachycardia

• Scarcity of data
• Amiodarone probably the most

effective1,2

• - Can cause bradycardia
• - Can hinder EP studies/ ablation

Extrapolate from cardiac pulseless VT/ VF versus placebo:

• 1. Kudenchuck PJ et al. N Engl

J Med 1999;341:871-878 versus lidocaine:

• 2. Dorian P et al. N Engl J Med

2002;346:884-890

Tachyarrhythmias-quasi-stable

Ventricular Tachycardia

• Scarcity of data
• Consider
• - Lidocaine gtt
• - Procainamide
• watch for hypotension and

prolonged QT

Tachyarrhythmias-quasi-stable

Ventricular Tachycardia

• Get EP involved
• May respond to beta-blockers or

calcium channel blockers

• May be amenable to ablation

Tachyarrhythmias- a long QT

1.Electrolytes

Hypokalemia Hypo-Mg2+ Hypo-Ca2+

• 2. DRUGS
• 3. Congenital

11/7/2017 13

Tachyarrhythmias

• 1. IV magnesium
• 2. Isoproterenol
• 3. Transvenous pacing
• 4. Unstable DC shock

THINK ABOUT TORSADES IF AMIODARONE ISN’T WORKING FOR “VF” OR PERHAPS MAKING THINGS WORSE

Bradyarrhythmias

• Important questions:

– Is this dynamic/ reversible/ vagal?

• IE, more likely benign
• IE, less likely respond to pacing
• IE, more likely transient

– Or is this structural

• IE, more likely dangerous
• IE, more likely needs pacing
• In the absence of SYMPTOMS, type II second

degree AV block or third degree AV block pacemaker

Bradyarrhythmias

+ +

• 1. Atropine1
• 2. Transcutaneous1

pacing OR Dopamine OR Epinephrine (then mention isoproterenol)

• 3. Consider

consultation ± transvenous pacing

• 1. AHA Guidelines. Circulation 2010;18:S749

Short term:

11/7/2017 14 Pacemakers

• Should be interrogated/ checked every 6

months

– Eg, doesn’t necessarily need to be checked while in the hospital

• Generally CAN now do MRIs with certain

restrictions regarding machine and personnel available

• We want to avoid RV pacing

– It’s an EP sin to RV pace frequently in anyone with a depressed EF

Biventricular Pacemaker His Bundle Pacing Implantable Cardioverter- Defibrillators

• Generally interrogated/ checked every 3 months
• All ICDs can also pace
• Anti-tachycardia pacing (ATP) is one way to

break a VT circuit without pain – But can always accelerate VT or lead to VF

• Generally ALSO CAN now do MRIs with certain

restrictions regarding machine and personnel available

• Trend towards longer delays in detection,

allowing faster rates with reduction in inappropriate shocks and DECREASE mortality

11/7/2017 15

• Pt. comes in with multiple,

recurrent shocks from his ICD

1.PUTS DEVICE IN “MAGNET MODE” 2.FOR AN ICD: INHIBITS THERAPY DETECTION 3.FOR A PACEMAKER: INHIBITS SENSING

• 1. Place external pads
• 2. Place magnet on chest

Thank You