Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
1
12 Lead EKG Interpretationfor Beginners
Johnny R. Tice, DNP, MA, CRNP, FNP-C, PMHNP-BC
Clinical Assistant Professor
University of Alabama Capstone College of Nursing
Objectives:
• Describe normal conduction of the cardiac cycle.
• Discuss standard leads of the 12 lead EKG.
• Examine systematic process of 12 lead EKG interpretation.
• Recognize common dysrhythmias encountered in clinical practice.
• Demonstrate 12 lead EKG interpretation in terms of rate, rhythm, and waveform/interval analysis.
12 EKG INTERPRETATION ROADMAP
03
02
04
05
06
01
HIGH SPEED TO ADVANCED SESSION.
PRACTICE
WAVEFORM - INTERVAL ANALYSIS
COMMON DYSRHYTHMIAS
RHYTHM
RATE
2
The Electrocardiogram
• The electrocardiogram (EKG) is a graphic recording of the electrical events of the cardiac cycle.
• Each event has a distinctive waveform, the study of which can lead to greater insight into a patient’s cardiac pathophysiology
3
The 12 Lead EKG
• Simple, convenient, and cost effective diagnostic tool
• Used as an adjunct to diagnosis cardiac pathology, electrolyte disturbance, and drug toxicity
• Only as capable as the user
Electrical Conduction in the Heart
Electrical Conduction in the Heart
4
Electrical Conduction in the Heart
Electrical Conduction in the Heart
Electrical Conduction in the Heart
5
Electrical Conduction in the Heart
Electrical Conduction in the Heart
The Cardiac Cycle
6
EKG Graph Paper
Waveforms and Intervals of Cardiac Cycle
Waveforms and Intervals of Cardiac Cycle
7
Waveforms and Intervals of Cardiac Cycle
Waveforms and Intervals of Cardiac Cycle
Waveforms and Intervals of Cardiac Cycle
8
Waveforms and Intervals of Cardiac Cycle
Waveforms and Intervals of Cardiac Cycle
Waveforms and Intervals of Cardiac Cycle
9
EKG Limb Leads: Frontal View
A lead: two electrodes of opposite polarity (bipolar) or one electrode and a reference point (unipolar)
Bipolar Limb Leads
Augmented Unipolar Limb Leads
10
Precordial Leads: Horizontal View
Precordial Leads: Horizontal View
Summary of Leads
11
12 Lead EKG
12 Lead EKG
12 Lead EKG
12
12 Lead EKG
Methods of Rate Determination
Count the number of R waves in a six second strip and multiply by 10
Methods of Rate Determination
13
Methods of Rate Determination
STEP 1: RATE
• HR of 60-100 per minute is normal
• HR > 100 = tachycardia
• HR < 60 = bradycardia
Rate Determination
60 BPM
75 BPM
80-85 BPM
130 BPM
14
STEP 2: RHYTHM
Regular or irregular rhythm?
12 EKG INTERPRETATION ROADMAP
03
02
04
05
06
01
HIGH SPEED TO ADVANCED SESSION.
PRACTICE
WAVEFORM - INTERVAL ANALYSIS
Common Dysrhythmias
RHYTHM
RATE
15
STEP 3: WAVEFORM -INTERVAL ANALYSIS
P WAVE• Direction of Deflection:
• Upright in Lead II• Inverted in AVR
• Amplitude: 2.5-3.0 mm
• Width: 0.06 – 0.10 sec
STEP 3: WAVEFORM -INTERVAL ANALYSIS
P WAVE
• Biphasic: indicates left atrial enlargement
• Notching: significant if ≥ 0.04 sec between peaks
STEP 3: WAVEFORM -INTERVAL ANALYSIS
P WAVE
• Notching also known as P-mitrale
• Shape of P-mitrale can vary in different patients
16
STEP 3: WAVEFORM -INTERVAL ANALYSIS
P WAVE
• Peaking: tall, peaked P waves: possible right atrial enlargement
• Absence of waveform: Consider junctional rhythm or sinoatrial block
STEP 3: WAVEFORM -INTERVAL ANALYSIS
P WAVE
• Peaking: tall, peaked P waves: possible right atrial enlargement
• Absence of waveform: Consider junctional rhythm or sinoatrial block
STEP 3: WAVEFORM -INTERVAL ANALYSIS
• NORMAL
• PROLONGED: > 0.20 seconds
• SHORTENED: < .0.12 seconds
P-R INTERVAL
17
STEP 3: WAVEFORM -INTERVAL ANALYSIS
QRS AMPLITUDE
Too low: ≤ 5mm leads I, II, IIIMinimal norm:5 mm in V1 and V67mm in V2 and V59 mm in V3 and V4Maximal norm:20-25 mm in limb leads25-30 mm in V leads
STEP 3: WAVEFORM -INTERVAL ANALYSIS
QRS: Q WAVE
• Should not be wider than 0.03 seconds
• View in context of overall cycle
• Consider depth, width, leads of appearance, and clinical presentation
STEP 3: WAVEFORM -INTERVAL ANALYSIS
QRS: Q WAVE• Considered pathologic if:
• Width > 30 ms (≥ 0.04)
• Width ≥ 25% of the height of the R wave
• If present in continuous leads, indicative of myocardial necrosis
18
STEP 3: WAVEFORM -INTERVAL ANALYSIS
QRS Complex
STEP 3: WAVEFORM -INTERVAL ANALYSIS
QRS COMPLEX
R WAVE PROGRESSION IN PRECORDIAL LEADS
STEP 3: WAVEFORM -INTERVAL ANALYSIS
QRS COMPLEX
TRANSITION ZONEUSUALLY V3 or V4
19
12 Lead EKG
R WAVE PROGRESSION NORMAL OR ABNORMAL?TRANSITION ZONE IN WHICH LEAD?
STEP 3: WAVEFORM -INTERVAL ANALYSIS
ST SEGMENT
IsoelectricNormal elevation: ≤ 1mm limb, ≤ 2mm precordialNormal depression: never ≥ 0.05mmNo shape angle or frank horizontal formAbnormal depression or abnormal elevation
STEP 3: WAVEFORM -INTERVAL ANALYSIS
20
STEP 3: WAVEFORM -INTERVAL ANALYSIS
T WAVE
• Slightly rounded and symmetrical• Sharply pointed or grossly notched T
waves should be examined with suspicion
STEP 3: WAVEFORM -INTERVAL ANALYSIS
QT INTERVAL• Normal: Interval varies
with rate
• Shortened: drug or electrolyte effect
• Prolonged: drug effect, heart disease, electrolyte
Practice
21
12 EKG INTERPRETATION ROADMAP
03
02
04
05
06
01
HIGH SPEED TO ADVANCED SESSION.
PRACTICE
WAVEFORM - INTERVAL ANALYSIS
Common Dysrhythmias
RHYTHM
RATE
Common Dysrhythmias
Sinus Arrhythmia
Multifocal Atrial Tachycardia
Common Dysrhythmias
• Paroxysmal Atrial Tachycardia
22
Common Dysrhythmias
• Supraventricular Tachycardia
Common Dysrhythmias
Atrial Fibrillation
Atrial Flutter
Common Dysrhythmias
Ventricular Tachycardia
Ventricular Fibrillation
23
Premature Ventricular Contractions
Common Dysrhythmias
• Junctional Rhythm
Common Dysrhythmias
• First Degree Block
24
Common Dysrhythmias
• Second Degree Block, MobitzType 1
• Second Degree Block, Mobitz type 2
Common Dysrhythmias
• Third Degree Heart Block
12 EKG INTERPRETATION ROADMAP
03
02
04
05
06
01
HIGH SPEED TO ADVANCED SESSION.
PRACTICE
WAVEFORM - INTERVAL ANALYSIS
Common Dysrhythmias
RHYTHM
RATE
25
PRACTICE
Normal Sinus Rhythm
PRACTICE
Second Degree AV Block: Type 1
PRACTICE
Hyperkalemia
26
PRACTICE
Atrial Fib RVR
PRACTICE
Dig Toxicity
PRACTICE
Atrial Flutter with Variable Block
27
PRACTICE
Third Degree Heart Block
PRACTICE
Supraventricular Tachycardia
PRACTICE
Hypokalemia
28
PRACTICE
Tricyclic Antidepressant Overdose
12 EKG INTERPRETATION ROADMAP
03
02
04
05
06
01
HIGH SPEED TO ADVANCED SESSION.
PRACTICE
WAVEFORM - INTERVAL ANALYSIS
Common Dysrhythmias
RHYTHM
RATE