ECG Interpertation - Brown Flashcards
Identify this condition based on symptoms and the rhythm strip presented:
pt complains of palpitations, shortness of breath with exertion, fatigue, and edema
exam reveals irregular pulse, variable BP, crackles on ascultation
Atrial Fibrillation
Rate: Variable, usually fast > 100 bpm
Rhy: Irregularly irregular (chaotic)
P-wave: Not consistently present or reproducible
PR: Not measurable
QRS: Normal (narrow,
Differentiate between atrial fibrillation, atrial tachycardia, and atrial flutter.
Identify this condition based on symptoms and the rhythm strip presented:
pt reports feeling light-headed and having fainted
signs: rapid HR
Paroxysmal Supraventricular Tachycardia
Rate: 140 - 250 bpm*
Rhy: Very Regular
P-wave: Lost in the T-wave, not typically observed on rhythm strip
PR: Not measurable
QRS: Normal (narrow,
Differentiate between atrial fibrillation, atrial tachycardia, and atrial flutter.
What pathology is present?
Rate: Variable, usually fast > 100 bpm
Rhy: Irregularly irregular (chaotic)
P-wave: Not consistently present or reproducible
PR: Not measurable
QRS: Normal (narrow,
Atrial Fibrillation
Differentiate between atrial fibrillation, atrial tachycardia, and atrial flutter.
Differential Diagnosis for a Wide-QRS Complex
in order of descending mortality
- hyperkalemia
- ventricular tachycardia
- idioventricular rhythm, including heart block
- drug effects and overdose (tricyclics)
- Wolff-Parkinson-White
- Bundle Branch Blocks & IVCD
- PVCs
- Aberrantly conducted complexes
What pathology is present?
Rate: Atrial rate 250 – 400 Ventricular rate Varies
Rhythm: Regular or Irregular
P-waves: Saw tooth deflection (F waves)
PR: Not measurable
QRS: Typically normal
Atrial Flutter
Differentiate between atrial fibrillation, atrial tachycardia, and atrial flutter.
Analyze the basic ECG components required to assess pathology to include, heart rate, rhythm, axis, and intervals
Rhythm Determination on an ECG
Is the distance between one QRS complex the same as the others?
If yes - the rhythm is regular
If no - the rhythm is irregular
Insignificant Q Waves
- do not meet the criteria for significance
- typically found in leads: I, aVL, V4-V6
Criteria for Diagnosis of MI: Injury Pattern
- ST segment elevation (1 mm or greater)
- T wave peaks initially then inverts later
Criteria for Diagnosis of MI: Infarction Pattern
Presence of SIGNIFICANT Q WAVES
- Q wave that is 1/3 total height of QRS
- wider than 40 ms
What pathology is described and shown on the ECG below:
QRS > 120 ms
rSR’ pattern V1-V2
slurred S-wave in I and V6
Right Bundle Branch Block
- QRS > 120 ms
- Axis is RAD or normal
- rsR’ pattern V1-V2
- slurred S-wave in I and V6
- NSSTT changes in V1 and V2
Describe the specific diagnostic criteria for Bundle branch blocks.
Analyze the basic ECG components required to assess pathology to include, heart rate, rhythm, axis, and intervals
Axis Determination
- on the ECG look at Limb Lead 1 and determine if the net deflection of the QRS complex is positive, negative or equal
- on the ECG look at Limb Lead aVF and determine if the net deflection of the QRS complex is positive, negative or equal
- determine where the lines cross
Analyze the basic ECG components required to assess pathology to include, heart rate, rhythm, axis, and intervals
ECG: Right Axis Deviation
- right bundle branch block
- right ventricular hypertrophy
- high lateral wall MI
- right anterior fascicular block
ECG Waveforms
(PQRST)
P wave: atrial depolarization
QRS wave: ventricular depolarization, also atrial repolarization occurs
J Point: end of the QRS wave and start of the ST segment
T Wave: ventricular repolarization
U Wave: late repolarization variant, can be a normal variant or assoicated with hypokalemia or hypomagnesiumemia
R-Wave Progression
- uses the precordial chest leads V1-V6
- r-wave (myocardial rotation) progresses from V1 through V6
- start small V1
- transition occurs V3,V4
- get big V6
Identify the common variances within normal ECGs.
Describe the specific diagnostic criteria for normal ECGs .
“Normal” ECG
- P waves upright in: I, II, V2-V6
- Small Q waves in: I, aVL, V4-V6
- Deep Q waves in: aVR occassionally III and V1
- T waves upright in: I, II, V3-V6
- T waves inverted in: aVR
- T waves variable in: III, aVL, aVF, V4-V6
Identify the pathology described below and shown on the ECG:
PR interval < 120 ms, normal P waves
Wide QRS complex
Presence of “delta-wave”
Wolff Parkinson White
“delta-wave” intial slurring of QRS
can also have secondary ST-T changes
What pathology is present?
Rate: 140-250 bpm
Rhythm: regular
P-Wave: not typically observed
PR: not measurable
QRS - normal (narrow < 0.12 sec)
Paroxysmal Supraventricular Tachycardia
Differentiate between atrial fibrillation, atrial tachycardia, and atrial flutter.
Analyze the basic ECG components required to assess pathology to include, heart rate, rhythm, axis, and intervals
QT Interval
QT
- measures a complete ventricular cycle (depolarization and repolarization)
- start of QRS to end of T wave
- normal is heart rate dependent
- HR of 60 - 400 ms
- HR of 100 - 320 ms
- as HR increases, QT interval decreases
- QT is probably prolonged if it exceeds more than HALF of the R-R interval
Analyze the basic ECG components required to assess pathology to include, heart rate, rhythm, axis, and intervals
QRS Interval
QRS
- normal < 3 boxes)
- beginning of QRS to end (J-Point)
- length of time for ventricular contraction
- prolonged interval
- bundle branch blocks
- IVCD
- WPW
- LVH
- RVH
- ventricular tachycardia
- PVCs
- idoventricular rhythm
- Develop a simple method that will allow you to consistently assess unknown ECGs for common pathologies.*
- *
- Gestalt - general impression (i.e. this is bad)
- Determine the Heart Rate
- Determine the Rhythm
- Measure the Longest Interval (PR, QRS, QT) in the limb leads
- Determine the Axis
- Asses the R-Wave Progression
Evaluate this rhythm strip:
Differentiate between atrial fibrillation, atrial tachycardia, and atrial flutter.
Paroxysmal Supraventricular Tachycardia
Rate: 140 - 250 bpm*
Rhy: Very Regular
P-wave: Lost in the T-wave, not typically observed on rhythm strip
PR: Not measurable
QRS: Normal (narrow,
Reentry process, presents abruptly for numerous reasons
Symptoms: light-headedness, syncope, racing heart; worsen angina and heart failure
Analyze the basic ECG components required to assess pathology to include, heart rate, rhythm, axis, and intervals
ECG: Left Axis Deviation
- left bundle branch block
- left ventricular hypertrophy
- inferior wall MI
- left anterior fascicular block
How to differentiate between atrial fibrillation, atrial tachycardia, and atrial flutter.
Is the rhythm regular?
- yes: PVST or atrial flutter
- no: atrial fibrillation or atrial flutter
Are P-waves (F-waves) present?
- yes: atrial flutter
- no: PVST or atrial fibrillation
Criteria for Diagnosis of MI: Ischemia
- ST segment depression (2 mm or greater)
- T wave inversion (symmetrical)
What pathology is described and shown on the ECG below?
QRS > 120 ms
Wide S waves V1-V4
Wide R waves in I and V6
Left Bundle Branch Block
- QRS > 120
- Axis is normal or LAD
- wide monomorphic S waves V1-V4
- wide monomorphic R waves in I and V6
- NSSTT changes in most leads
Describe the specific diagnostic criteria for Bundle branch blocks.
Identify the common variances within normal ECGs.
Describe the specific diagnostic criteria for normal ECGs.
what to note/evaluate on each ECG lead
- location and morphology of P waves
- QRS pattern (presence of Q-waves)
- ST segment (elevation or depression)
- T wave changes
**Review all leads except aVR
Differential Diagnosis of ST-Elevation
- Acute STEMI
- Printzmetal’s Angina
- Ventricular Aneurysm
- Pericarditis
- Normal Variant - early repolarization
Evaluate this rhythm strip:
Atrial Flutter
Rate: Atrial rate 250 – 400 Ventricular rate Varies
Rhythm: Regular or Irregular
P-waves: Saw tooth deflection (F waves)
PR: Not measurable
QRS: Typically normal
Differentiate between atrial fibrillation, atrial tachycardia, and atrial flutter.
Evaluate this Rhythm Strip:
Atrial Fibrillation
Rate: Variable, usually fast > 100 bpm
Rhy: Irregularly irregular (chaotic)
P-wave: Not consistently present or reproducible
PR: Not measurable
QRS: Normal (narrow,
Symptoms: palpitations, SOB, fatigue, DOE, CP, edema
Signs: irregular pulse, variable BP, crackles edema
Causes: organic heart disease, valvular disease, thyroid, HTN
Differentiate between atrial fibrillation, atrial tachycardia, and atrial flutter.
System to Evaluate Rhythm Strips
- Determine Heart Rate
- Determine Rhythm
- Presence of P-wave (location and morphology)
- a single P-wave should proceed each QRS complex
- should bear a family resemblance to all other P-waves
- Measure PR and QRS intervals
Analyze the basic ECG components required to assess pathology to include, heart rate, rhythm, axis, and intervals
Heart Rate Determination on an ECG
Paper speed is 25 mm/sec or 300 big boxes per second
take 300 divided by the number of big boxes from 1 QRS to the next
i.e. in this example: 300/3.8 = ~80
Analyze the basic ECG components required to assess pathology to include, heart rate, rhythm, axis, and intervals
PR Interval
PR:
- normal: 120-200 ms (3-5 boxes)
- beginning of P wave to the beginning of the QRS complex
- best measured in limb lead 2
- conduction through the AV node
- short PR interval:
- pre-excitation syndrome (WPW, LGL)
- PACs
- long PR interval - lots of causes
- refered to as “First Degree AV Block”
