OBJECTIVES
Pediatric Cardiac Rhythm Analysis for the Non-Cardiac Nurse
Amy Jo Lisanti, MSN, RN, CCRN, CCNS, PhD (candidate) Clinical Nurse Specialist, Cardiac Intensive Care Unit, The Children’s Hospital of Philadelphia
CARDIAC ANATOMY
But I’m not a cardiac nurse!
Describe the basic anatomy and physiology of the heart. Explain cardiac electrical conduction system and its relationship to the cardiac cycle. Identify the common arrhythmias in infants and children. Recognize the nursing assessments and actions related to the arrhythmias.
7 year old Jessica presents to the ED in anaphylactic shock after stepping on a beehive and getting stung several times. Monitor – HR is 186! What else are you looking for?
Figure 1
THE CARDIAC CYCLE
THE CARDIAC CYCLE KEY POINT = Blood flows the path of LEAST RESISTANCE !!!
Figure 2
Figure 3
Figure 4
REGULATING CARDIAC OUTPUT
CARDIAC OUTPUT
Cardiac Output = Stroke volume x Heart rate
Therefore, CO is the amount of blood pumped out of the ventricles each minute.
Stroke volume = Amount of blood pumped out of the ventricles with each beat
Preload Afterload Contractility
Autonomic Nervous System Intrinsic Regulation Renin-AngiotensinAldosterone System Natriuretic Peptides Baroreceptors Chemoreceptors RA stretch receptors
Figure 5
SPECIAL CONSIDERATION = INFANTS!!
THE ACTION POTENTIAL…. UGH!
CONTRACTION
Figure 6
Figure 9
THE ELECTRICAL CONDUCTION SYSTEM
THE ELECTROCARDIOGRAM
THE HIGHWAY OF THE HEART:
SA Node
AV Node
Bundle of His
ECG = The Graphic Representation of the Electrical Activity of the Heart ECG Picture Depends on Lead Placement Figure 8
Purkinje Fibers
Figure 7
THE ELECTROCARDIOGRAM
ECG PAPER
QRS complex S-T Segment
Voltage
P-R Interval
Time
P wave QRS Duration
T wave
DEPOLARIZATION = CONTRACTION 0.2 Seconds
0.04 Seconds
THE CARDIAC CYCLE
THE CARDIAC CYCLE
Atrial Depolarization: P-wave and PR interval
QRS Complex = Ventricular Depolarization
R
Atria Contract and Ventricles Fill (“Atrial Kick”) Q
THE CARDIAC CYCLE
T Wave = Ventricular REpolarization This is the resting phase of the Cardiac Cycle. No Interruptions Allowed!
S
SINUS RHYTHM Determined by the SA Node – Age Dependent Electrical Impulse flows through Normal Conduction Pathway Age Ranges for Normal Sinus Rhythm (NSR) Newborn to 12 months = 100-180 1- 3 years = 90 - 150 3 - 5 years = 70 - 140 5 – 8 years = 65 – 130 8 years and older = 60 – 110
Sinus Bradycardia – Below these age ranges Sinus Tachycardia – Above these age ranges Sinus Arrhythmia – SA node fires at irregular rhythm
RHYTHM ANALYSIS
RHYTHM ANALYSIS
• What’s Normal??
• What is my Patient’s ASSESSMENT?
• What am I even looking at????
• Is my patient Hemodynamically Stable?
RHYTHM ANALYSIS
ECG WAVEFORM CHANGES
Is the rhythm regular or irregular? Identify the waveforms
Is there a P wave before every QRS complex? T wave morphology/ST segment
Measurements
PR interval QRS duration QT/QTc
Case study
32 day old baby boy at the pediatrician’s office for his 1 month old check-up. He was born in the 75th percentile and now sits in the 10th percentile for weight. Mom says that he always seems to tire out during feeds. VS- T 36.9, HR 220, RR 52, BP 62/30
Artifact
Patient Movement Loose Electrodes Improper Grounding Faulty Monitor
Physiologic
Hypoxia Ischemia Hypertrophy Electrolytes
PATIENT ASSESSMENT IS KEY!!!!
Potassium Calcium Magnesium
Medications Cardiac Surgery
ATRIAL ARRHYTHMIAS
Premature Atrial Contractions (PACs) Paroxysmal Atrial Tachycardia (PAT/SVT) Atrial Flutter Atrial Fibrillation
PREMATURE ATRIAL CONTRACTION (PAC)
ATRIAL FLUTTER
ATRIAL FIBRILLATION
PVCs
Wide QRS Complex No P-Wave
PAROXYSMAL ATRIAL TACHYCARDIA (PAT/SVT)
VENTRICULAR ARRHYTHMIAS
Premature Ventricular Contraction (PVC)
Ventricular Tachycardia (V-tach)
Ventricular Fibrillation (V-fib)
V-TACH
TORSADE DE POINTES
VENTRICULAR FIBRILLATION
Cardiac Muscle is quivering! No Coordinated Contraction!
NO
Cardiac Output! CPR and DEFIB STAT! Figure 10
PROLONGED QT
RISK = SUDDEN DEATH
QT Interval changes with Heart Rate QTc is the “Corrected” QT Interval
Adjusted for the Heart Rate (R-R Interval)
HEART BLOCKS
FIRST-DEGREE AV BLOCK
First-degree AV Block Second degree AV Block
14yo male with osteosarcoma in his right distal femur. Treatment: Doxorubicin, Cisplatin, Methotrexate Zofran q8 hours for nausea and vomiting Pre-chemo ECHO and ECG were normal Ordered another ECHO and ECG prior to next dose of Doxorubicin. QTc=0.52
QTc is greater than 0.42 sec in men QTc is greater than 0.44 sec in women
Prolonged QT:
Case Example
Mobitz Type I (aka Wenckebach) Mobitz Type II
Third degree AV Block
Figure 10
MOBITZ I - WENCKEBACH
COMPLETE HEART BLOCK
MOBITZ Type II
ASYSTOLE
NO ELECTRICAL ACTIVITY NO PACEMAKER TO INITIATE ACTIVITY
REVIEW
Most Common Arrhythmias in Children:
LETHAL ARRHYTHMIA
Very Resistant to Resuscitation Efforts
Thank you for your attention!
Children with Congenital Heart Defects may present with any arrhythmia. Children with other chronic illnesses on certain medications may develop arrhythmias.
Figures
References Hebbar, A. & Hueston, W. (2002). Management of common arrhythmias: Part I. Supraventricular Arrythmias. American Family Physician, 65, 2479-2486. Morelli, P., Biancaniello, T., Chandran, L. (2007). The essentials of pediatric ECGs. Contemporary Pediatrics, 24(9), 49-60. Mowery, B. & Suddaby, E. (2001). ECG interpretation: What is different in children? Pediatric Nursing, 27, 224, 227-231. Urden, L., Stacy, K., Lough, M. (2006). Thelan’s Critical Care Nursing: Diagnosis and Management. St. Louis, MO: Mosby Elsevier.
Bradycardia (most often related to Hypoxia) Sinus Arrhythmia (changes in vagal tone from inspiration and expiration, benign) Asystole (can follow bradycardia if untreated) Supraventricular Tachycardia
Figure 1: Retrieved July 10, 2008, from http://www.medicalook.com/diseases_images/heart-diseases1.jpg Images 2-4: Retrieved July 10, 2008, from http://en.wikipedia.org/wiki/Cardiac_cycle Figure 5: Retrieved July 10, 2008, from http://www.themdsite.com/graphics/ION_14a.jpg Figure 6: Retrieved July 10, 2008, from http://virtuallyshocking.com/wpcontent/uploads/2006/10/CepBasicsPresentation.011-001.png Figure 7: Retrieved July 10, 2008, from http://www.uptodate.com/patients/content/images/card_pix/Heart_con duction_system.jpg Figure 8: Retrieved July 10, 2008, from http://nobelprize.org/educational_games/medicine/ecg/ecgreadmore.html Figure 9: Retrieved April 16, 2010, from http://www.carolguze.com/images/cellorganelles/actin-myosin.jpg Figure 10: Retrieved April 16, 2010, from http://www.lond.ambulance.freeuk.com/ecg/1degavbk.jpg Cullen, J. (2008). Color ECG tracing pictures, used with permission.
