Diagnostic and Management Approach of Bardycardia_dr.yuli

7/25/2019 Diagnostic and Management Approach of Bardycardia_dr.yuli

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Diagnostic and Management

Approach of BardycardiaBudi Yuli Setianto, MD, PhD

FIHA, FINASIM, FAsCC, FAPSIC

Department of Cardiology and Vasculer Medicine Faculty ofMedicine Gadjah Mada University-Functional Medical StaffSardjito Hospital Yogyakarta

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Case Scenario

An 80-year-old woman reports

feeling weak and short of breath

for 2 hours while walking shortdistances. She feels exhausted

moving from the car to the ED

stretcher. On physical exam she

is pale and sweaty; HR = 35 bpm;BP = 90/60 mm Hg; RR = 18 rpm.

Rhythm: see next slide.

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80-Year-Old Woman:

Symptomatic Bradycardia

Identify A, B, and C

Which one is most likely

to be her rhythm?

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A

B

C


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Rhythms to Learn

Sinus bradycardia

Heart blocks

1stdegree

2nddegree type I

2nddegree type II

3rddegree

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Cardiac Conduction System 1

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Left bundle branch

Posterior division

Anterior division

Purkinje fibersRight bundle branch

Bundle of His

AV node

Internodal pathways

Sinus node


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Cardiac Conduction System 2

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Rates of Intrinsic

Cardiac Pacemakers

Primary pacemaker

Sinus node (60-100 bpm)

Escape (Subsidiary) pacemakers

AV junction (40-60 bpm)

Ventricular (


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Determining the Rate

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Determining the Rate

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Analyzing Rhythm Strips

Key questions

Are QRS complexes present?

Are P waves present?

How is the P wave related to the

QRS complex?

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Relationship of P Waves and QRS

Complexes

Every P wave is followed by a QRS complex

with a normal PR interval

Every P wave is followed by a QRS complex but

the PR interval is prolonged

Some P waves are notfollowed by a QRS

complex; more P waves than QRS complexes

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What Is This Rhythm?

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Sinus Bradycardia

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First Degree AV Block

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Diagnosis?

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Second Degree AV Block Type I

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Diagnosis?

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Second Degree AV Block Type II

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Third Degree AV Block Type III

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Differentiation of Second- and

Third-Degree AV Blocks

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More Ps than QRSs

PR fixed?

no

QRSs thatlook alikeregular?

no

yes

yes

yes

2nd-degree AV blockFixed

Mobitz II

3rd-degree AV block

2nd-degree AV blockVariableMobitz I

Wenckebach


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Bradycardia Algorithm (1 of 2)

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Bradycardia

Heart Rate less than 60 bpm andinadequate for clinical condition

Maintain patent airway; assist breathing as needed

Give oxygen

Monitor ECG (identify rhythm), blood pressure, oximetry

Establish IV access

Serious signs or symptoms of poor

perfusion caused by the bradycardia

(eg. acute altered mental status, ongoing chest pain,

hypotension or other signs of shock)


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Bradycardia Algorithm (2 of 2)

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Observe/Monitor

Prepare for transvenous pacing Treat contributing causes Consider expert consultation

PoorPerfusion

AdequatePerfusion

Prepare for transcutaneous

pacing;use without delay for

high degree block (type II

second -degree block or third-

degree AV block)

Consider Atropine 0.5 mg/IV

while awaiting pacer. May

repeat to a total dose of 3 mg. If

ineffective, begin pacing.

Consider Epinephrine (2 to 10

g/min) or dopamine (2 to 10

g/kg/min infusion while

awaiting pacer or if pacing

ineffective.

Reminders

If pulseless arrest develops go to

Pulseless Arrest Algorithm Search for and treat possible contributing

factors:

Hypovolemia

Hypoxia

Hydrogen ion (acidosis)

Hypo/Hyper-kalemia

Hypoglycemia Hypothermia

Toxins

Tamponade, cardiac

Tension pneumothorax

Thrombosis (coronary or

pulmonary)

Trauma (hypovolemia, inc ICP)


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Treatment?

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Treatment?

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Transcutaneous Pacing

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Indications for


Hemodynamically unstable bradycardias

In the setting of AMI: sinus node dysfunction,

type II 2nd-degree block, 3rd-degree heart

block

Bradycardia with symptomatic ventricular

escape beats

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The pacing rate is set at 80 beats per minute.

In conscious bradycardic patients, pacing isbegun in the demand mode at rates slightly faster

than the native rhythm and at minimal currentoutput

The current is gradually increased by 5 to 10 mAat a time until cardiac capture is documented,

which defines the pacing threshold. The finalcurrent output should be set at the pacingthreshold or 5 to 10 mA above it.

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In the setting of a bradysystolic arrest or with

unconscious patients, it is recommended to turn

the stimulating current to maximal output (200

mA) to ensure ventricular capture

Once capture is achieved, the current may be

gradually decreased until loss of capture, whichdefines the pacing current threshold

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Transcutaneous Pacing:

Capture vs No Capture

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Pacing below threshold:no capture

Pacing above threshold:with capture

Pacing Spike

Capture: Spike + broad QRS

QRS: opposite polarity

25 Feb 88 Lead I Size 1.0 HR=41

25 Feb 88 Lead I Size 1.0 HR=43 35 mA

25 Feb 88 Lead I Size 1.0 HR=71 60 mA

Bradycardia: No Pacing

Pacing Below Threshold (35 mA): No Capture

Pacing Above Threshold (60 mA): With Capture (Pacing-PulseMarker )

Bradycardia: no pacing

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Diagnostic and Management Approach of Bardycardia_dr.yuli