1. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Escape and Usurpation Escape: Predominant pacemaker slows, lower pacemaker takes over at slower rate. An escape beat is a beat that comes in after a pause Usurpation: Irritable lower pacemaker takes control and becomes new pacemaker at a faster rate, suppressing or inhibiting the previous pacemaker

2. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Figure 2-11 Escape

3. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Figure 2-12 Usurpation

4. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis EKG Paper Graph paper that EKGs are printed on Divided into small blocks 1 millimeter in height and width Counting horizontally measures time (intervals) Counting vertically measures amplitude

5. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Figure 2-13 EKG Paper

6. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis EKG Paper Delineations One small block is 0.04 seconds Five small blocks = one big block One big block = 0.20 seconds 25 small blocks = 1 second Five big blocks = 1 second 1500 small blocks = 1 minute 300 big blocks = 1 minute

7. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis 12-Lead EKGs and Rhythm Strips 12-Lead EKG: Printout of the heart’s electrical activity viewed from 12 different angles as seen in 12 different leads A lead is an electrocardiographic picture of the heart’s electrical activity Rhythm Strip: Printout of only one or two leads at a time

8. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Figure 2-14 (A) Single- and (B) double-lead rhythm strips.

9. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Benefit of Double-Lead Strips Both leads show the same rhythm, just viewed from two different angles Therefore both leads have the same rhythm, intervals, and heart rate

10. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Benefit of Double-Lead Strips Two leads provide twice the chance of identifying the rhythm. For example, P waves may not be visible in one lead, but are very clear in the other Having two leads shows how the same rhythm can look different in different leads

11. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Figure 2-15 12-Lead EKG

12. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. EllisIntervals Measurement of time between the P-QRS- T waves and complexes Measurements allow determination of heart’s efficiency at conducting its impulses down the pathway

13. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. EllisIntervals PR: Measured from beginning of P to beginning of QRS QRS: Measured from beginning of QRS to its end QT: Measured from beginning of QRS to end of T wave

14. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Figure 2-16 Intervals

15. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Intervals Practice: Enlarged Rhythm Strip 1 PR__________ QRS__________ QT__________

16. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Intervals Practice: Enlarged Rhythm Strip 2 PR__________ QRS__________ QT__________

17. Copyright ©2012 by Pearson Education, Inc. All rights reserved. EKG Plain and Simple, Third Edition Karen M. Ellis Intervals Practice: Enlarged Rhythm Strip 3 PR__________ QRS__________ QT__________