ECG & Machine Principles
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Transcript of ECG & Machine Principles
ECG &Machine Principles
ECGELEMENTS
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ELECTROCARDIOGRAPHER
ECG PAPER
ECG PAPER
ECG LEADS
ECG LEADS
ECG Vectors & Deflections
Frontal plane Horizontal Plane
CARDIAC Axis
Find Most Isoelectric
Find Perpendicular
Because aVL is POSITIVE (upward deflection on the ECG), the axis is approaching aVL, so it’s – 30°. If it was NEGATIVE on the ECG, the axis would be at the tail of the arrow, so 150°.
Is it positive or negative?
This patient’s axis is deviated to the LEFT. (– 30°)
ECGTRACING EXERCISE # 1
WHAT WE NEED TO KNOW…1. PAPER DEFINITIONS2. DOMINANT WAVES3. AMPLITUDE4. DURATION5. WAVE-WAVE RELATION 6. WAVE-LEAD RELATION
ECGTRACING EXERCISE # 2
AHA CONSIDERATIONSPatient & Machine Dependent
1. Lead axis & Heart Vector projection on lead.2. Lead as a vector (direction and length).
Unipolar?3. Strength or signal magnitude variables.4. Impedances.5. Artifact, Filtering & Frequency cut offs.6. Movement, Position, Rib direction,
Imaginary lines, Amputations, Female breasts, Implants and Obesity.
7. PMH. CC. CI.8. Computer Interpretation.
AHA CONSIDERATIONSOperator Dependent
1. Skin cleaning. Retraining.2. 12 Electrode TYPICAL placement. 3 lead?3. Limb leads placement.4. Precordial Placement of leads.5. V4 – V6 horizontal plane.6. V5 between V4 &V6.7. Common placement errors. High, low,
curved, switched.8. Reproducibility?9. Labeling.
ECGCLINICAL UTILITY
ECGUtility Arrhythmias. Acute Coronary Syndromes (ACS). Conduction Disturbances. Hydro – Electrolytic (HE)
Abnormalities. Electrical & Structural Abnormalities.Also: Monitoring Anti-
ArrhythmicTreatment. Non Cardiological Pre-Op Assesment. Screening High Risk Activities. (Work/
sports)
ECG & ARRHYTHMIASInterpretation Method
ARRHYTHMIAClassificationsABNORMALITY
1. Conductiona. AV Blocksb. Bundle Blocks
2. Origina. Supraventricular
- Extrasystoles- Escape Beats- Junction
b. Ventricular- Extrasystoles- Escape Beats
HEART RATE1. Tachyarrhythmia
sa. Regularb. Irregular
2. Bradyarrhythmiasa. Regularb. Irregular
ARRHYTHMIASTACHYCARDIAS
1. ST (r)
2. A. FIB. (i)
3. A. FLU. (r)4. WPW5. TSVP
(r)6. JT
(r)7. MFAT
(i)
8. TV MONOM. (r)
9. TV POLIM. (i)10. TDP (i)11. VF
(i)BRADYCARDIAS
12. SB13. AV BLOCKS
- 1°- 2° MI- 2° MII- 3°
14. HBB BLOCKS15. TC Pacing.
CA RHYTHMS16. VENTRICULAR
FIBRILATION
17. PULSELESS VENTRICULAR TACHYCARDIA
18. PULSELESS ELECTRICAL ACTIVITY
19. ASYSTOLE
ARRHYTHMIAInterpretation Method
1. Identify what’s normal = RHYTHM & AXIS
2. Establish Heart Rate (HR) = FREQUENCY
3. Determine Regularity = PATTERN4. QRS Width = ORIGIN.5. P Morphology = ATRIAL ACTIVITY6. P/ QRS Ratio = AV CONDUCTION
7. ST & T = VENT. REPOLARIZATION
RHYTHM
Definition of Rhythm. Sinus Rhythm Variations of Rhythm. Alterations of Rhythm Long L-II
CARDIAC Axis
HR & PATTERN
ORIGIN QRS COMPLEX Wide VENTRICULAR Narrow SUPRAVENTRICULAR
AURICULAR Activity:P WAVE P WAVE
- Anterograde- Retrograde
AV Conduction: PR INTERVAL
Second – Degree AV Block (2 types)
ECGQT INTERVAL
Useful in Tachyarrhythmiaslike TORSADE DE POINTS (a type of Ventricular Polimorphic Tachycardia)
Torsade de Points
ECGST SEGMENT & T WAVE
More useful in Acute Coronary Syndromes& HE disturbances.