1. The EKG

2. Animation – Listen Carefully http://www.nhlbi.nih.gov/health/dci/Diseas es/hhw/hhw_electrical.htmlhttp://www.nhlbi.nih.gov/health/dci/Diseas es/hhw/hhw_electrical.html

3. ELECTROCARDIOGRAM EKG (ECG) Remember: The heart has its own electrical system. Do you the know the 4 parts involved?

4. What is an EKG? What is an Electrocardiogram? –A measurement of the electrical activity in the heart. What 4 parts of the heart are used in electrical signal? –Sinoatrial node, atrioventricular node, Bundle of His, Purkinje Fibers

5. 1. SA - Sinoatrial Node 1.initiates an electrical sequence 2. AV - Atrioventricular Node 3.Purkinje Fibers 4.Bundle of His

6. ECG ECG = measurement of electrical activity over time Measured using electrodes –Electrical contacts on the skin –Electrodes measure voltage between the electrodes over time Can be used to measure abnormal heart rhythms of the heart –Such as damaged muscle tissue during a myocardial infraction –Can diagnose irregular heart beat, irregular speed of contractions, angina (tissue damage), or even tissue death (myocardial infarction).

7. Electrodes Can be placed in different areas to achieve different results/measurements Detect the electrical impulse being produced by the heart –detecting the difference between the charges in the areas where the electrodes are attached –The greater the intensity of the impulse, the greater the difference in the charges, and the larger the upward or downward peak will appear on the EKG

9. Can You Label All of the EKG Parts?

11. What Does an EKG Look Like? R Q P = P Wave- Just before atrial contraction QRS Complex- Impulse causing ventricle contraction T= T Wave – Ventricles relax p S T P Through T = Systolic Pressure T Through P = Diastolic Direction of impulse

13. Table 2 Standard Resting Electrocardiogram Interval Times P–R interval0.12 to 0.20 s QRS intervalless than 0.12 s Q–T interval0.30 to 0.40 s

14. How is it Measured? Heart generates electrical current At rest… –Heart muscle is polarized (more positively charged ions on the outside of the heart cells –More negatively charged ions are inside Then the positive ions move to the inside of cells and negatively charged ions move to the outside –The flow of electrons into the cells cause an electrical current –This is called depolarization Then the positive ions move back to the outside of the cells and negatively charged ions move back to inside –This is called repolzarization

15. Current passes through body to skin. Current can be measured with an electrocardiogram. (EKG,ECG) Vernier.com

18. Depolarization and Repolarization At rest… –Heart muscle is polarized (more positively charged ions on the outside of the heart cells –More negatively charged ions are inside Then the positive ions move to the inside of cells and negatively charged ions move to the outside –The flow of electrons out of the cells cause an electrical current –This is called depolarization Then the positive ions move back to the outside of the cells and negatively charged ions move back to inside –This is called repolarization

19. - - - - - + + + + + Depolarization

20. + + + + + - - - - - Heart Cells Cause Muscle Contraction Repolarization

21. Common Issues P Wave Absent –Lack of normal depolarization of the atria QRS Complex Absent –indicates the electrical impulse was blocked before it reached the ventricles Abnormally shaped complexes –abnormal spread of the impulse through the muscle tissue, such as in myocardial infarction pulse cannot follow its normal pathway because of tissue death or injury

22. What does all of this mean? P wave –Atrium contract/depolarize –Blood flows through atrium into ventricles –SA node sends signal to AV node Q –Atrium relax/repolarize R –Left Ventricle contract/depolarize –AV node sends signal to Purkinje fibers S –Right Ventricle contract/depolarize –AV nodes sends signal to Purkinje fibers T wave –Ventricles relax/repolarize

23. Excel Results for EKG Time (seconds) Test SubjectP Wave (start)QRST Wave (end)P-R IntervalQRS ComplexQ-T ComplexHeart Rate (BPM) Walters 1 Walters 2 Walters 3

24. Myocardial Infarction

25. EKG in LabView

26. Quiz Question 1 What is the main item that neutrophils attack in the body? a)Bacteria b)Viruses c)Allergies d)Cancer

27. Quiz Question 2 The white blood cell count in the body is normally _____. a)1,000 to 2,000 b)4,000 to 10,000 c)15,000 to 20,000 d)95,000 to 100,000

28. Quiz Question 3 The systolic phase of an EKG begins at _____. a)P b)Q c)R d)S e)T

29. Quiz Question 4 The R point corresponds with ______. a)Atrium contraction b)Left Ventricle contraction c)Right Ventricle contraction d)Ventricular relaxation

30. Quiz Question 5 The T wave corresponds with ______. a)Atrium contraction b)Left Ventricle contraction c)Right Ventricle contraction d)Ventricular relaxation