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PEM|COR: TACHYCARDIA
Frank P. Carnevale, M.D.Department of Pediatrics
Division of Pediatric Emergency MedicineState University of New York at Buffalo
November 13, 2013
PEM|CoR: 2013-2014
09-18-13: Hypovolemic & Distributive Shock
10-30-13: Cardiogenic & Obstructive Shock
11-13-13: Tachycardia 01-29-14: Bradycardia 02-12-14: Fever Work-up 03-19-14: ATLS & RSI Issues 04-30-14: Cardiac Arrest 05-07-14: Neonatal Resuscitation
Learning Objectives
Differentiate SVT from ST Recognize and manage pediatric
tachycardia with a pulse and adequate vs. poor perfusion
Describe how and when to use vagal maneuvers, adenosine, and synchronized cardioversion for the treatment of SVT
The sequel to the Halloween Candy Monster (2013)…
http://youtu.be/RK-oQfFToVg
Learning Objectives
Differentiate SVT from ST Recognize and manage pediatric
tachycardia with a pulse and adequate vs. poor perfusion
Describe how and when to use vagal maneuvers, adenosine, and synchronized cardioversion for the treatment of SVT
Normal Heart Rate(per minute)
Age Awake Rate Sleeping Rate
0 to 3 months 85 to 205 80 to 160
3 months to 2 years 100 to 190 75 to 160
2 to 10 years 60 to 140 60 to 90
> 10 years 60 to 100 50 to 90
Tachyarrhythmias
Tachycardia is a HR that is fast compared with the normal HR for the child’s age
Sinus Tachycardia is a normal response to stress or fever
Tachyarrhythmias are fast abnormal rhythms originating in the atria or ventricles
Tachyarrhythmias can be tolerated without symptoms for a variable amount of time
They can then cause acute hemodynamic compromise from shock to cardiac arrest
Calculation for cardiac output?
A. HR x BPB. BP x CVPC. MAP - ICPD. HR x SVE. SV x MAP
A. B. C. D. E.
0% 0% 0%0%0%
20
Coronary perfusion occurs…
A. Mostly during systole
B. Mostly during diastole
C. About equally during systole and diastole
D. Only during inspiration
E. Only during expiration
A. B. C. D. E.
0% 0% 0%0%0%
20
Effect on Cardiac Output
CO = HR x SV Increase HR and you increase CO (to a point) You reach a point when diastole is so short that
the heart doesn’t have time to fill When end-diastolic filling time decreases, SV
decreases and therefore CO decreases Also, coronary perfusion occurs during
diastole, so this can be compromised This, along with increased metabolic demand
from tachycardia can lead to cardiogenic shock
One tiny box on an EKG = ____sec
A. 0.2B. 0.02C. 0.1D. 0.03E. 0.04
A. B. C. D. E.
0% 0% 0%0%0%
20
Definition of wide QRS complex?
A. > 0.09 secB. > 0.07 secC. > 0.12 secD. < 0.1 secE. < 0.2 sec
A. B. C. D. E.
0% 0% 0%0%0%
20
Wide QRS seen in:
A. Sinus TachB. SVTC. VTD. Atrial flutterE. A fib
A. B. C. D. E.
0% 0% 0%0%0%
20
Tachyarrhythmias:Narrow vs. Wide QRS complexesNarrow Complex (< 0.09 second)
Wide Complex (> 0.09 second)
Sinus Tachycardia (ST) Ventricular Tachycardia (VT)
Supraventricular tachycardia (SVT)
SVT with aberrant intraventricular conduction
Atrial Flutter
Sinus Tachycardia
A sinus node discharge rate faster than normal for a child’s age
Typically develops in response to body’s need for increased cardiac output
Common causes: exercise, pain, anxiety, tissue hypoxia, hypovolemia, shock, fever, metabolic stress, injury, toxins, and anemia
ST has beat-to-beat variability.
A. TrueB. False
True
False
0%0%
20
In ST, P waves are present and normal in appearance.
A. TrueB. False
True
False
0%0%
20
ECG characteristics of ST:
A. PR normal; R-R constant
B. PR normal; R-R variable
C. PR variable; R-R constant
D. PR variable; R-R normal
A. B. C. D.
0% 0%0%0%
20
ECG Characteristics of ST
Heart Rate Beat-to-beat variability with changes in activity or stress level•Infants < 220 bpm•Children < 180 bpm
P waves Present/normal
PR interval Constant, normal duration
R-R interval Variable
QRS complex Narrow (<0.09 second)
Supraventricular Tachycardia(SVT)
An abnormally fast rhythm originating above the ventricles
Most commonly caused by a reentry mechanism that involves an accessory pathway
The most common tachyarrhythmia that causes cardiovascular compromise during infancy
SVT: Clinical Presentation
A rapid, regular rhythm that appears abruptly and may be episodic
In infants, often diagnosed when symptoms of CHF develop
Infants: irritability, poor feeding, rapid breathing, unusual sleepiness, vomiting, and pale, mottled, gray, or cyanotic skin
Older children: palpitations, SOB, chest pain, dizziness, light-headedness, syncope
Which is incorrect about SVT?
A. Lack of beat-to-beat variability
B. HR usually >240C. P waves
absent/abnormalD. R-R interval
constantE. QRS < 0.09
A. B. C. D. E.
0% 0% 0%0%0%
20
SVT: ECG Characteristics
Heart Rate No beat-to-beat variability with changes in activity or stress level•Infants > 220 bpm•Children > 180 bpm
P waves Absent or abnormal (may appear after the QRS complex)
PR interval Because P waves are usually absent, PR interval cannot be determined
R-R interval Constant
QRS complex In over 90% of children, usually narrow (<0.09 second); wide complex is uncommon
ST vs. SVT
Characteristic ST SVT
History Gradual onset; Hx of pain, fever, dehydration, hemorrhage, etc.
Abrupt onset/ termination/both; Infant- CHF; Child-palpitations
Physical exam Signs of underlying cause of ST (fever, hypovolemia)
Signs of CHF
Heart rate Infant: < 220 bpmChild: < 180 bpm
Infant: > 220 bpmChild: > 180 bpm
Monitor Variability in HR with changes in activity/stim.
No variability
ECG P waves present/normal/upright in I/aVF
P waves absent/abnormal/inverted in II/III/aVF, following QRS
Chest x-ray Small heart, clear lungs Signs of CHF (enlarged heart, pulm edema)
Learning Objectives
Differentiate SVT from ST Recognize and manage pediatric
tachycardia with a pulse and adequate vs. poor perfusion
Describe how and when to use vagal maneuvers, adenosine, and synchronized cardioversion for the treatment of SVT
Treatment for Sinus Tach?
A. FluidsB. AntipyreticsC. Search for and
treat causeD. PropranololE. Hyperventilatio
n
A. B. C. D. E.
0% 0% 0%0%0%
20
Initial treatment for stable SVT?
A. AdenosineB. CardioversionC. DefibrillationD. AmiodaroneE. Vagal
maneuvers
A. B. C. D. E.
0% 0% 0%0%0%
20
Initial treatment for stable VT?
A. DefibrillationB. Vagal
manueversC. ProcainamideD. AtropineE. Cardioversion
A. B. C. D. E.
0% 0% 0%0%0%
20
Initial tx for unstable VT?
A. DefibrillationB. EpinephrineC. AmiodaroneD. CardioversionE. Adenosine
A. B. C. D. E.
0% 0% 0%0%0%
20
Initial tx for unstable SVT?
A. DefibrillationB. CardioversionC. AmiodaroneD. Vagal
maneuversE. Adenosine
A. B. C. D. E.
0% 0% 0%0%0%
20
PALS Tachycardia Algorithm.
Copyright © American Heart Association
Learning Objectives
Differentiate SVT from ST Recognize and manage pediatric
tachycardia with a pulse and adequate vs. poor perfusion
Describe how and when to use vagal maneuvers, adenosine, and synchronized cardioversion for the treatment of SVT
Vagal Maneuvers
The HR decreases when the vagus nerve is stimulated by slowing conduction through the AV node
If child stable, may repeat once If child unstable, may try these while
preparing for pharmacologic or electrical cardioversion
Infant: Bag of ice/water to the upper face for 15 seconds (don’t occlude nose or mouth)
Older child: Valsalva by blowing through an occluded or very narrow straw
Adenosine
Drug of choice for treatment of SVT Acts at AV node to block conduction for
10 sec Common pitfall: drug administered too
slowly or with and inadequate IV flush 2-syringe technique A 10 sec period of asystole, brady, or 3rd
degree block may follow administration 1st dose 0.1mg/kg (max 6 mg) IV/IO 2nd dose 0.2mg/kg (max 12 mg) IV/IO
Synchronized Cardioversion
Defibrillators can deliver unsynchronized and synchronized shocks
Unsynchronized: shock delivered any time during the cardiac cycle; used for defibrillation because there is no organized QRS
Synchronized: used for cardioversion from SVT and VT with a pulse; shock delivery is timed to coincide with the R wave of the QRS; goal is to prevent VF that results when you shock during the T wave
Cardioversion Pitfalls
Must select sync mode prior to EACH charge If using paddles, must press both buttons
simultaneously When you press shock button, the unit may
seem to pause before delivering shock (while waiting for capture)—keep holding down the buttons (if paddles) until shock delivered
If the R waves are low amplitude, may need to increase the gain or select a different ECG lead to achieve capture
Learning Objectives
Differentiate SVT from ST Recognize and manage pediatric
tachycardia with a pulse and adequate vs. poor perfusion
Describe how and when to use vagal maneuvers, adenosine, and synchronized cardioversion for the treatment of SVT
Let’s practice some scenarios with the PEM Fellows
Station #1: Huma Station #2: Jeremy Station #3: Jen Station #4: Tara Station #5: Meghan Station #6: Danielle
