Electrocardiography and Pulmonary Function Testing

1. 52 Electrocardiography and Pulmonary Function Testing

2. Learning Outcomes 52.1 Describe the anatomy and physiology of the heart. 52.2 Explain the conduction system of the heart. 52.3 Describe the basic patterns of an electrocardiogram (ECG). 52.4 Identify the components of an electrocardiograph and what each does.

3. Learning Outcomes (cont.) 52.5 Explain how to position the limb and precordial electrodes correctly. 52.6 Describe in detail how to obtain an ECG. 52.7 Identify the various types of artifacts and potential equipment problems and how to correct them.

4. Learning Outcomes (cont.) 52.8 Identify how the ECG is interpreted. 52.9 Identify common arrhythmias. 52.10 Summarize exercise electrocardiography. 52.11 Explain the procedure of Holter monitoring. 52.12 Describe forced vital capacity.

5. Learning Outcomes (cont.) 52.13 Describe the procedure of performing spirometry. 52.14 Describe the procedure for obtaining a performing peak expiratory flow rate. 52.15 Describe the procedure for performing pulse oximetry testing.

6. Introduction • Patients often have cardiovascular or respiratory problems • Medical assistant • Perform screening and/or diagnostic testing • Understand the anatomy and physiology of the heart and respiratory system

7. The Medical Assistant’s Role • Electrocardiography • Graphic recording of the electrical impulses of the heart • Uses • Evaluate symptoms of heart disease • Check effectiveness or side effects of medications • General examination

8. The Medical Assistant’s Role (cont.) • Pulmonary function tests • Measure and evaluate a patient’s lung capacity and volume • Uses • Help detect and diagnose pulmonary problems • Monitor respiratory disorders • Evaluate effectiveness of treatments

9. Valves Septum Anatomy of the Heart • Muscular double pump • Right – receives blood from the body, sends it to the lungs • Left – receives blood from the lungs, sends it out to all parts of the body • Four chambers • Two atria • Two ventricles

10. Physiology of the Heart • Systole – contraction phase • Diastole – relaxation phase • Cardiac cycle – sequence of contraction and relaxation • Cardiac muscle fibers are interconnected so when one is stimulated to contract, all fibers in the group contract.

11. Conduction System of the Heart • Cardiac cycle • Controlled by specialized tissues in the heart wall that transmit electrical impulses • Impulses cause muscle to contract and relax

12. Conduction System of the Heart (cont.) SA Node Bundle of His Pacemaker of the heart Sets rhythm of contractions Located in septum between ventricles Bundle Branches Relay impulse to Purkinje fibers AV Node Bottom of right atrium Impulse delayed slightly Purkinje Fibers Located in ventricle walls Contraction of ventricles

13. Electrocardiography Transmission, magnitude, and duration of electrical impulses of the heart Polarity Having a positive and negative pole Resting cell Positive outside Negative inside Depolarization Impulse that initiates a contraction Repolarization Period of electrical recovery following depolarization Prior to polarized (resting) state Conduction System of the Heart (cont.)

14. Conduction System of the Heart (cont.) • Basic pattern of the ECG • Waves (deflections) are labeled P, Q, R, S, T, U

15. Apply Your Knowledge Truly Great! ANSWER: True or False ___ The AV node is the heart’s pacemaker. ___ The medical assistant does not perform ECGs or PFTs. ___ The bundle branches relay impulses to the Purkinje fibers in the ventricles. ___ The heart is resting in the polarized state. ___ Depolarization initiates contractions of atria and ventricles. ___ Repolarization occurs before depolarization. F SA F may T T T following F

16. The Electrocardiograph • Electrical impulses are detected through the skin • Measures • Amplifies – signal is increased • Records using the stylus

17. The Electrocardiograph (cont.) • Types of electrocardiographs • Standard machine – 12-lead, which records 12 different views at once • Single channel – one lead and records only one view

18. The Electrocardiograph (cont.) • Electrodes and electrolyte products • Electrolyte – enhances transmissions of electric current • Electrodes • Ten areas of the body • Right and left arms • Right and left legs • Six locations on the chest • Enables physician to pinpoint origin of problems

19. The Electrocardiograph (cont.) • Leads • Provide different images of electrical activity • Marked automatically on the ECG • Limb leads • Three standard – I, II, III • Three augmented – AVF, AVR, AVL • Precordial leads – V1 through V6

20. 0.04 sec 0.2 sec 1 mm(0.1 mV) 5 mm(0.5 mV) 5 mm 1 mm The Electrocardiograph (cont.) • ECG paper • Single or multichannel available • Heat- and pressure-sensitive • Standardized to permit uniform interpretation • Vertical axis – strength of impulse (millivolt) • Horizontal axis – time

21. Controls Standardization control Speed selector – 25mm/sec standard Sensitivity control – adjusts height of tracing Lead selector – enables selection of a single lead Centering control – adjusts position of stylus Line control – adjusts darkness of line On/Off switch The Electrocardiograph (cont.)

22. Apply Your Knowledge ANSWER: Matching: ___ Adjusts position of stylus A. Vertical axis ___ Adjusts height of tracing B. Sensitivity control ___ Adjusts darkness of tracing C. Precordial leads ___ Measures strength of impulse D. Horizontal axis ___ Measures time E. Limb leads ___ AVF, AVR, AVL F. Amplification ___ V1 through V6 G. Centering control ___ Increases signal H. Stylus temperature control G B H A D E C F Superbly Matched!

23. Preparing to Obtain an ECG • Proper technique essential • Preparing the room and equipment • Other electrical equipment turned off • Quiet room, comfortable temperature • Check machine • Warm up • Adequate paper

24. Preparing to Obtain an ECG (cont.) • Preparing the patient • Introduce yourself • Explain the procedure • Answer questions • Ensure patient comfort • Perform ECG procedure

25. Applying the Electrodes and the Connecting Wires • Electrodes – disposable are most common • Positioning electrodes • Use consistent technique • Limb electrodes – place at same level • Precordial electrodes – specific intercostal spaces Precordial Lead Placement

26. Applying the Electrodes and the Connecting Wires (cont.) • Attaching wires • Numbers and letters correspond to those for electrodes • Connect limb wires first • Precordial in same sequence as electrodes • Avoid tension on wires

27. Standardize Run the ECG Automatic Manual Multiple-channel Check the tracing Clear/free from artifact Operating the Electrocardiograph

28. Apply Your Knowledge • In addition to making sure the room is comfortable for the patient and the ECG machine is ready, what else should you do to prepare for performing an ECG? ANSWER: All other electrical equipment in the room should be turned off. • Electrodes are placed at how many positions on the body? ANSWER: Ten: four limb and six chest positions.

29. Apply Your Knowledge • What should you do just prior to running the ECG to see if the machine needs adjusting? What should you do upon completion of the test? ANSWER: Standardize the electrocardiograph prior to running the tracing. Upon completion of the ECG, you should check the tracing to be sure is it clear and free from artifact. Electrifyingly Great!

30. Outside interference Improper handling Troubleshooting Artifacts • Causes • Improper technique • Poor conduction

31. Troubleshooting Artifacts (cont.) • Wandering baseline – somatic interference or mechanical problems • Flat line – loose or disconnected wire • Extraneous marks – careless handling

32. Causes AC interference – machine picks up current from other electrical equipment Somatic interference – muscle movement Identifying source of interference Check tracings for leads I, II, and III If unable to identify source, stop and notify supervisor of problem Leave patient connected Troubleshooting Artifacts (cont.)

33. Completing the Procedure • Acceptable tracing • Label properly • Disconnect wires from electrodes • Remove electrodes/wipe off electrolyte • Assist patient up • Prepare room appropriately • Mount tracing if necessary

34. Apply Your Knowledge • What are four general causes of artifacts? ANSWER: They are improper technique, poor conduction, outside interference, and improper handling of the tracing. • What should you after running an ECG? ANSWER: After making sure the tracing is acceptable, you should label it properly, disconnect wires from electrodes, remove electrodes and wipe off electrolyte, assist patient up, and prepare the room appropriately for the next patient. Bravo!

35. Interpreting the ECG • Not a medical assistant responsibility • Knowing how they are interpreted will enable you to recognize a problem requiring immediate attention

36. Interpreting the ECG (cont.) • Heart rhythm • Regularity of the heartbeat • Distances between complexes and waves is normally consistent • Rhythm strip obtainedfrom lead II

37. Heart rate • If regular – count QRS complexes in a 6-second strip and multiply by 10 • Irregularities • Conduction abnormalities • Reaction to medication Interpreting the ECG (cont.)

38. Interpreting the ECG (cont.) • Intervals and segments • Variations in length and position • Conduction disturbances • Myocardial infarctions • Electrolyte disturbances • Wave changes –normally similar in each lead

39. Interpreting the ECG (cont.) • Cardiac arrhythmias – irregularities in heart rhythm • Ventricular fibrillation – life-threatening with no cardiac output • Premature ventricular contractions – heartbeats that originate from the ventricles • Bundle branch blocks – impulse through the heart is slowed or blocked • Atrial fibrillation – electrical disturbance in the atria and/or AV node

40. Apply Your Knowledge ANSWER: Matching (may be used more than once): ___ Number of QRS complexes in 6 sec x 10 A. V-fib ___ Cannot identify “P” waves B. Heart rhythm ___ Produces no cardiac output C. Bundle branch block ___ Originates in ventricles D. Atrial fibrillation ___ Slows or stops impulse E. Heart beat ___ Multiple impulses from sites outside SA node F. PVC ___ “Saw-tooth” image ___ Regularity of heart beat ___ Due to irritable of ventricular heart muscle E D A F C D A Fantastic! B F

41. Exercise Electrocardiography • Stress test – measures the heart’s response to a constant or increasing workload • Uses • Determine how a diseased heart is functioning • Screen a patient for heart disease • Determine patient’s ability to start an exercise program

42. Patient education Record activities What to avoid How to check monitor Ambulatory Electrocardiography • Resting ECG may not show abnormalities • Holter monitor • Monitors heart over a 24-hour period of normal activity • Uses • Diagnosis • Evaluate status post-MI

43. Ambulatory Electrocardiography (cont.) • Connecting the patient • 3 or 5 electrodes • Prep skin prior to placing • Tape in place to eliminate tension and ensure that electrodes stay in place for entire time of testing • Put fresh battery in the machine • Check tape • Ensure that machine is turned on

44. Apply Your Knowledge What is the purpose for stress testing and Holter monitor testing? ANSWER: Stress testing is used to measure the heart’s response to a constant or increasing workload. A Holter monitor is used to obtain a tracing over a period of time when a resting ECG shows no abnormalities. Both are used for diagnosing cardiac conditions or for monitoring current treatments and medications. Correct!

45. Anatomy of the Respiratory System • Nose • Pharynx • Larynx • Trachea • Two bronchi • Bronchioles • Alveoli

46. Physiology of the Respirator System • External respiration – alveoli • Ventilation • Inspiration • Expiration • Diffusion • Internal respiration (perfusion) – exchange of O2 and CO2 between blood and tissues

47. Pulmonary Function Testing • Evaluates lung volume and capacity • Uses • Evaluate of shortness of breath • Detect and classify of pulmonary disorders • Evaluate effectiveness of treatments

48. Spirometry • Measures air taken in by and expelled by the lungs • Forced vital capacity (FVC) – greatest volume of air that can be expelled with a rapid, forced expiration • Types of spirometers: • Computerized • Mechanical

49. PerformingSpirometry • Technique similar for all types – be consistent • Patient preparation • Inform the patient about conditions and activities that could affect the test accuracy • Explain procedure and its purpose • Explain the need for a nose clip • Be sure patient forms a tight seal around the mouthpiece • Position the patient properly • Demonstrate correct procedure

50. PerformingSpirometry (cont.) • Performing the maneuver • Urge patient to blow hard and to continue blowing • Provide feedback on performance • Obtain three acceptable maneuvers • Observe the patient’s symptoms • Notify physician immediately if symptoms occur