The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.
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Transcript of The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.
![Page 1: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/1.jpg)
The 12-Lead EKGChapter 12
Robert J. Huszar, MD
Instructor
Patricia L. Thomas, MBA, RCIS
![Page 2: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/2.jpg)
Outline
• Electrical Axes and Vectors
• The electrical current, vectors, and the lead axis
• The hexaxial reference figure
• The QRS axis
• Determination of Axis
![Page 3: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/3.jpg)
Electrical Axes & Vectors
• Instantaneous cardiac vector-the electrical current generated by the depolarization or repolarization of the atria or ventricles at any given moment
• Graphically as an arrow that has magnitude, direction, and polarity
• Length of the shaft of the arrow represents the magnitude of the electrical current
• Orientation or position of the arrow indicates the direction of flow of the electrical current
• The tip of the arrow represents the positive pole of the electrical current
• The tail is the negative pole
![Page 4: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/4.jpg)
![Page 5: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/5.jpg)
Magnitude, Direction, and Polarity
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Normal DepolarizationFigure 12-2
• Interventricular Septum 1 & 2
• Right Ventricle 3
• Left Ventricle (thick lateral portion) 3
• Left Ventricular (lateral/posterior/base) 4
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![Page 8: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/8.jpg)
The Hexaxial Reference Figure
• Composite of the two triaxial reference figures (limb leads+ augmented leads)
• Purpose is to determine the direction of the QRS axis
• Each +& - pole is assigned a degree number 00 to 1800
• The top are given – numbers• The bottom are given + numbers• NOT TO BE CONFUSED WITH the - & + poles of
the lead axes
![Page 9: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/9.jpg)
![Page 10: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/10.jpg)
Electrical Axis Calculation
• Plotting of the net direction or the electrical axis
• QRS axis is most important it is correlates with the anatomy of the heart
• Pathophysiology causes a shift in the axis
![Page 11: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/11.jpg)
![Page 12: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/12.jpg)
Calculate the Axis
• 1. Calculate the algebraic sum of QRS in Leads I & III
• 2. Plot the vector results on a triaxial reference system
• 3. Draw the perpendicular until Lead I & III cross.
• 4. Draw a separate line from the center to the intersection of the two perpendiculars gives the electrical axis.
• 5. Determine location (normal, RAD or LAD)
![Page 13: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/13.jpg)
![Page 14: The 12-Lead EKG Chapter 12 Robert J. Huszar, MD Instructor Patricia L. Thomas, MBA, RCIS.](https://reader036.fdocuments.us/reader036/viewer/2022062511/551c196d550346a84f8b57e6/html5/thumbnails/14.jpg)
Practical Method EA
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THE ENDOF
CHAPTER 12
Hauszar Robert, Basic Dysrhythmias, Interpretation & Management, Third Edition, Mosby, Inc. 2002, pp. 171-187.
Scheidt, Stephen M.D., Basic Electrocardiography,CIBA-GEIGY Pharmaceuticals, 1986
pp. 3,18,19