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Chapter 36 Electrocardiography Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. Chapter 36 Electrocardiography Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

Electrocardiogram (ECG) Part of a complete physical examination Ø Preoperative work-up Used as a Electrocardiogram (ECG) Part of a complete physical examination Ø Preoperative work-up Used as a diagnostic tool to detect heart disease Painless, noninvasive procedure Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 2

Conditions Detected by an ECG Cardiac arrhythmia Ø Ischemia Ø Abnormal cardiac rhythm Heart Conditions Detected by an ECG Cardiac arrhythmia Ø Ischemia Ø Abnormal cardiac rhythm Heart damage due to poor blood supply Presence of electrolyte imbalance Effects of cardiac medication Myocardial infarction (MI) Ø Damage caused by a heart attack Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 3

Medical Assistant’s Responsibilities Properly prepare the patient Correctly operate the equipment Identify and eliminate Medical Assistant’s Responsibilities Properly prepare the patient Correctly operate the equipment Identify and eliminate artifacts Properly labeling the ECG record Understand perform routine maintenance Ø Proper care and storage of the ECG machine Never interpret ECG Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 4

The Cardiac Cycle Rhythmic cycle of the pumping heart Ø Contraction of ventricles Ø The Cardiac Cycle Rhythmic cycle of the pumping heart Ø Contraction of ventricles Ø One heartbeat Systole Relaxation of ventricles Ø Diastole Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 5

Role of the SA and AV Nodes SA node Pacemaker of the heart Ø Role of the SA and AV Nodes SA node Pacemaker of the heart Ø Sends electrical impulses to both atria, causing them to contract Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 6

Role of the SA and AV Nodes (cont. ) AV node Receives electrical impulse Role of the SA and AV Nodes (cont. ) AV node Receives electrical impulse from the SA node Ø Transmits impulse to bundle of His, bundle branches, and then to Purkinje fibers, causing ventricles to contract Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 7

Conduction System Review SA node (sinoatrial node) Ø Group of specialized cells in upper Conduction System Review SA node (sinoatrial node) Ø Group of specialized cells in upper right atrium AV node (atrioventricular node) Located in the lower portion of the right atrium Ø Monitors the heartbeat Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 8

Conduction System Review (cont. ) Bundle of His Ø Receives impulses from the AV Conduction System Review (cont. ) Bundle of His Ø Receives impulses from the AV node and passes to bundle branches Purkinje fibers Receives impulses from the bundle branches Ø Cause the ventricles to contract Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 9

The Conduction System of the Heart Copyright © 2010, 2006 by Saunders, an imprint The Conduction System of the Heart Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 10

ECG Patterns Tracings show the heart is functioning and ready Ø Action phase of ECG Patterns Tracings show the heart is functioning and ready Ø Action phase of contraction Ø Polarization Depolarization Resting or relaxation phase Ø Repolarization Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 11

Phases of the ECG Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Phases of the ECG Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 12

Wave Patterns of the ECG P wave Ø QRS complex Ø Contraction of the Wave Patterns of the ECG P wave Ø QRS complex Ø Contraction of the ventricles (systole) T wave Ø Contraction of the atria Resting of the heart (diastole) U wave Ø Occurs occasionally in a normal ECG Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 13

ECG Terms Baseline Ø Flat line that separates the various waves Segment Ø Small ECG Terms Baseline Ø Flat line that separates the various waves Segment Ø Small portion of ECG between two waves showing heart activity Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 14

ECG Terms (cont. ) Interval Ø Indicates time, showing an entire wave with a ECG Terms (cont. ) Interval Ø Indicates time, showing an entire wave with a small portion of a segment Normal sinus rhythm (NSR) Ø Appearance of one P wave, QRS complex, T wave, and U wave (occasional) in each heartbeat, without arrhythmias Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 15

P Wave First electrical impulse shown on an ECG Represents atrial contraction Impulse leaving P Wave First electrical impulse shown on an ECG Represents atrial contraction Impulse leaving the SA node (atrial depolarization) P wave is small, rounded, upright, not exceeding 2 to 3 mm in height Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 16

P Wave (cont. ) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier P Wave (cont. ) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 17

PR Segment and PR Interval PR segment Time it takes from SA to AV PR Segment and PR Interval PR segment Time it takes from SA to AV node Ø Measured from end of P wave to start of QRS complex Ø PR interval Time from SA node through the atria and the AV node, to bundle of His, to Purkinje fibers Ø Normal time— 0. 12 to 0. 2 second Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 18

QRS Complex Shows as impulse reaches Purkinje fibers Ventricular depolarization (ventricular contraction) of both QRS Complex Shows as impulse reaches Purkinje fibers Ventricular depolarization (ventricular contraction) of both ventricles Q wave Ø R wave Ø Downward deflection (negative) Upward deflection (positive) S wave Ø Downward and upward deflection Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 19

QRS Complex (cont. ) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier QRS Complex (cont. ) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 20

ST Segment, T Wave, QT Interval, and U Wave ST segment Ø Time interval ST Segment, T Wave, QT Interval, and U Wave ST segment Ø Time interval between the end of ventricular contraction and beginning of ventricular relaxation T wave Indicates resting (repolarization) of the heart Ø Wave is broad and rounded Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 21

ST Segment, T Wave, QT Interval, and U Wave (cont. ) QT interval Ø ST Segment, T Wave, QT Interval, and U Wave (cont. ) QT interval Ø Time needed for ventricles to contract and recover U wave Ø Small upward curve; can be present in normal ECG Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 22

ST Segment, T Wave, QT Interval, and U Wave (cont. ) Copyright © 2010, ST Segment, T Wave, QT Interval, and U Wave (cont. ) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 23

Necessary Equipment for a “Good” ECG Tracing Electrodes Leads Amplifier Galvanometer Stylus Copyright © Necessary Equipment for a “Good” ECG Tracing Electrodes Leads Amplifier Galvanometer Stylus Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 24

ECG Paper Heat- and pressure-sensitive standardized graph paper Vertical and horizontal lines, making up ECG Paper Heat- and pressure-sensitive standardized graph paper Vertical and horizontal lines, making up small, thin-lined squares within a large dark-lined square 25 small squares (1 × 1 mm) equal one large square Ø One large square made up of 25 small squares equals 5 × 5 mm Ø Each wave measured by counting the squares Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 25

ECG Paper (cont. ) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier ECG Paper (cont. ) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 26

ECG Machines Multichannel Prints three leads at a time Ø Uses 8 × 11 ECG Machines Multichannel Prints three leads at a time Ø Uses 8 × 11 -inch ECG paper Ø Single channel Records each lead separately Ø Uses special plastic-coated paper, 3 inches wide Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 27

Single-Channel ECG Machine Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. Single-Channel ECG Machine Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 28

Multichannel ECG Machine Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. Multichannel ECG Machine Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 29

Multichannel ECG Paper Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. Multichannel ECG Paper Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 30

Standardization Process of making certain that ECG taken on one machine will compare with Standardization Process of making certain that ECG taken on one machine will compare with a tracing taken on another machine Standardize to 10 -mm height Ø 10 small boxes Machine set to run at 25 mm/second Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 31

The Standardization Mark Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. The Standardization Mark Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 32

Patient Preparation Explain procedure to patient Remove all clothing above the waist Roll up Patient Preparation Explain procedure to patient Remove all clothing above the waist Roll up pant leg of long pants, roll down socks Ø Gown opens in front Ø Remove any jewelry that would interfere with electrode placement Place patient in supine position Clean and dry skin for electrode placement Ø Remove excessive hair, if necessary Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 33

Electrode Placement Arm electrodes placed on the fleshy surfaces Ø Leg electrodes are placed Electrode Placement Arm electrodes placed on the fleshy surfaces Ø Leg electrodes are placed on calf Ø Tab ends point down toward feet Tab ends point toward the head Chest leads (V 1 -V 6) Tab ends point downward Ø Leads placed in varying positions across the chest Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 34

Proper Placement of Limb Electrodes Copyright © 2010, 2006 by Saunders, an imprint of Proper Placement of Limb Electrodes Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 35

Proper Placement of Chest Electrodes Copyright © 2010, 2006 by Saunders, an imprint of Proper Placement of Chest Electrodes Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 36

Procedure: 12 -Lead Single-Channel ECG Sanitize hands Prepare patient Position patient Help patient to Procedure: 12 -Lead Single-Channel ECG Sanitize hands Prepare patient Position patient Help patient to relax Apply electrodes Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 37

Procedure: 12 -Lead Three-Channel ECG Sanitize hands Prepare patient Position patient Help patient to Procedure: 12 -Lead Three-Channel ECG Sanitize hands Prepare patient Position patient Help patient to relax Apply electrodes Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 38

Unusual Placement of Electrodes Occurs when special situations arise Prevents electrodes from being placed Unusual Placement of Electrodes Occurs when special situations arise Prevents electrodes from being placed in their usual locations Amputations Ø Casts Ø Bandages Ø Wounds Ø Large breasts Ø Overweight Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 39

Placement of Electrodes Correct attachment critical in producing accurate tracing Ø Need positive, negative, Placement of Electrodes Correct attachment critical in producing accurate tracing Ø Need positive, negative, and ground leads Electrical energy flows from negative electrode toward positive electrode Right arm always negative, left leg positive Ø Right leg is ground Ø View heart from four major surfaces Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 40

Four Major Surfaces of the Heart Copyright © 2010, 2006 by Saunders, an imprint Four Major Surfaces of the Heart Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 41

Standard Limb Leads (Bipolar) Lead I: records tracings from upper right chest to upper Standard Limb Leads (Bipolar) Lead I: records tracings from upper right chest to upper left chest Ø Electrodes placed on right arm (–) and left arm (+) Lead II: records tracings from upper right chest to left leg Considered “rhythm strip” Ø Electrodes placed on right arm (–) and left leg (+) Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 42

Standard Limb Leads (Bipolar) (cont. ) Lead III: records tracings from upper left chest Standard Limb Leads (Bipolar) (cont. ) Lead III: records tracings from upper left chest to left leg Ø Electrodes placed on left arm (–) and left leg (+) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 43

The Standard Leads Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. The Standard Leads Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 44

Augmented Leads (Unipolar) Same electrode placement as standard leads Ø Measure the activity of Augmented Leads (Unipolar) Same electrode placement as standard leads Ø Measure the activity of one electrode at a time, making it bigger and easier to read and interpret a. VR (augmented right arm) Ø Records activity midway between LA, LL, to RA Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 45

Augmented Leads (Unipolar) (cont. ) a. VL (augmented left arm) Ø Records activity halfway Augmented Leads (Unipolar) (cont. ) a. VL (augmented left arm) Ø Records activity halfway between RA, LL, to LA a. VF (augmented left foot) Ø Records activity halfway between RA, LA, to LL Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 46

The Augmented Leads Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. The Augmented Leads Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 47

Chest Leads Also called precordial leads, or V leads Six leads (V 1 -V Chest Leads Also called precordial leads, or V leads Six leads (V 1 -V 6) measuring in only one direction Ø Located in front of the heart View heart in a horizontal plane from anterior and lateral surfaces of the heart Accurate placement essential for obtaining a good tracing Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 48

Placement of Chest Leads V 1: right sternal border in 4 th intercostal space Placement of Chest Leads V 1: right sternal border in 4 th intercostal space V 2: left sternal border in 4 th intercostal space V 3: midway between V 2 and V 4: left midclavicular line in 5 th intercostal space V 5: left anterior axillary line in 5 th intercostal space V 6: left midaxillary line in 5 th intercostal space Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 49

The V Leads Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. The V Leads Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 50

Lead Codes Manual single-channel ECG machine Push marker button to specify lead Consist of Lead Codes Manual single-channel ECG machine Push marker button to specify lead Consist of a series of dots and dashes Newer ECG machines automatically specify lead names with same code Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 51

The Lead Marking Codes Copyright © 2010, 2006 by Saunders, an imprint of Elsevier The Lead Marking Codes Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 52

ECG Results Tracing gives physician information about the current condition of patient’s heart Comparing ECG Results Tracing gives physician information about the current condition of patient’s heart Comparing with baseline ECG provides a more accurate picture of patient’s condition Ø Baseline ECG taken when patient is in good health with no cardiac problems or on previous visit Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 53

Types of Artifacts Somatic tremor Ø Voluntary or involuntary muscle movements Wandering baseline Occurs Types of Artifacts Somatic tremor Ø Voluntary or involuntary muscle movements Wandering baseline Occurs when electrodes not properly applied to skin Ø Tension on lead wires, dirty electrodes, hairy chests, dried-out sensor pads Ø Alternating current Ø Electrical interference Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 54

Somatic Tremor Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All Somatic Tremor Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 55

Wandering Baseline Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All Wandering Baseline Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 56

Alternating Current Interference Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. Alternating Current Interference Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 57

Artifacts or Arrhythmia Artifacts Ø Caused by movement or electrical interference outside the patient; Artifacts or Arrhythmia Artifacts Ø Caused by movement or electrical interference outside the patient; may be machine or environment Arrhythmia Ø Result of electrical activity within the patient’s heart; patient’s health status Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 58

Types of Sinus and Atrial Arrhythmias Sinus bradycardia Sinus tachycardia PAC (premature atrial contraction) Types of Sinus and Atrial Arrhythmias Sinus bradycardia Sinus tachycardia PAC (premature atrial contraction) PAT (paroxysmal atrial tachycardia) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 59

Sinus Bradycardia Occurs when heartbeat less than 60 beats/minute; normal rhythm P wave appears Sinus Bradycardia Occurs when heartbeat less than 60 beats/minute; normal rhythm P wave appears normal PR interval is normal QRS complex is not affected Often seen in well-conditioned athletes Ø Can be result of a myocardial infarction or medication Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 60

ECG Tracing of Sinus Bradycardia Copyright © 2010, 2006 by Saunders, an imprint of ECG Tracing of Sinus Bradycardia Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 61

Sinus Tachycardia Heartbeat more than 100 -180 beats per minute Ø Results in decreased Sinus Tachycardia Heartbeat more than 100 -180 beats per minute Ø Results in decreased ventricular filling, causing decreased blood pressure P wave, PR interval, and QRS complex appear normal; QT interval shortens Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 62

Sinus Tachycardia (cont. ) Found in patients: After strenuous exercise Ø With hemorrhage Ø Sinus Tachycardia (cont. ) Found in patients: After strenuous exercise Ø With hemorrhage Ø With dehydration Ø With heart failure and anxiety Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 63

ECG Tracing of Sinus Tachycardia Copyright © 2010, 2006 by Saunders, an imprint of ECG Tracing of Sinus Tachycardia Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 64

Premature Atrial Contraction (PAC) Occurs when electrical impulse starts before the next expected beat Premature Atrial Contraction (PAC) Occurs when electrical impulse starts before the next expected beat P wave abnormally shaped or inverted Ø Ø Rate and remainder of ECG pattern are normal Patient feels a “skipped” beat Atria irritated from stimulation caused by: Ø Ø Ø Caffeine Tobacco Stress Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 65

ECG Tracing of PAC Copyright © 2010, 2006 by Saunders, an imprint of Elsevier ECG Tracing of PAC Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 66

Paroxysmal Atrial Tachycardia (PAT) Sudden onset of tachycardia of 150 to 250 beats per Paroxysmal Atrial Tachycardia (PAT) Sudden onset of tachycardia of 150 to 250 beats per minute P wave is shaped differently, often inverted Ø Cardiac complexes close together Tachycardia stops spontaneously as suddenly as it started Patient experiences “pounding” in chest Etiology: may be brought on by anxiety, stress, excessive stimulants Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 67

ECG Tracing of PAT Copyright © 2010, 2006 by Saunders, an imprint of Elsevier ECG Tracing of PAT Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 68

Ventricular Arrhythmias Most dangerous of the arrhythmias Usually cause incomplete ventricular contractions, resulting in Ventricular Arrhythmias Most dangerous of the arrhythmias Usually cause incomplete ventricular contractions, resulting in insufficient filling of ventricles Ø Results in insufficient systemic circulation and oxygenation Premature ventricular contraction (PVC) Ventricular tachycardia (V tach) Ventricular fibrillation (V fib) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 69

Premature Ventricular Contraction (PVC) Occur when heart has been injured or diseased Ventricles receive Premature Ventricular Contraction (PVC) Occur when heart has been injured or diseased Ventricles receive impulse prematurely and contract before their time Ø QRS complex becomes wider and bizarre in shape Etiology Ø Electrolyte imbalance Ø Caffeine and other stimulants Ø Emotions and stress Ø Cardiac disease Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 70

ECG Tracing of a PVC Copyright © 2010, 2006 by Saunders, an imprint of ECG Tracing of a PVC Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 71

Ventricular Tachycardia (V Tach) Defined as three or more consecutive PVCs with heart rate Ventricular Tachycardia (V Tach) Defined as three or more consecutive PVCs with heart rate more than 100 beats/minute Ø QRS complex wide, oddly shaped, regular rhythm The longer, more sustained the VT, the more serious it becomes Cardiac output decreases; blood supply to organs decreases Ø Patient complains heart “beating out of the chest” Ø Can escalate into ventricular fibrillation and cardiac standstill Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 72

ECG Tracing of V Tach Copyright © 2010, 2006 by Saunders, an imprint of ECG Tracing of V Tach Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 73

Ventricular Fibrillation (V Fib) Most life threatening of all arrhythmias Ventricles twitch, causing ineffective Ventricular Fibrillation (V Fib) Most life threatening of all arrhythmias Ventricles twitch, causing ineffective pumping action—no circulation Death occurs in 3 to 5 minutes without treatment Treatment includes: Ø CPR Defibrillation Ø Administration of cardiac drug Ø Use of AED Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 74

ECG Tracing of V Fib Copyright © 2010, 2006 by Saunders, an imprint of ECG Tracing of V Fib Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 75

Automated External Defibrillator (AED) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Automated External Defibrillator (AED) Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 76

Pacemaker Rhythm Artificial pacemaker delivers electrical impulses to the heart muscle to cause contraction—acts Pacemaker Rhythm Artificial pacemaker delivers electrical impulses to the heart muscle to cause contraction—acts like SA and AV nodes Causes depolarization and contraction Produces an ECG tracing with “pacemaker spikes” Ø Indicates the pacemaker mechanism is firing Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 77

ECG Tracing of a Pacemaker Rhythm Copyright © 2010, 2006 by Saunders, an imprint ECG Tracing of a Pacemaker Rhythm Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 78

Holter Monitor 24 - to 48 -hour ECG-type test that monitors the ambulatory patient Holter Monitor 24 - to 48 -hour ECG-type test that monitors the ambulatory patient Ø Uses five leads Picks up intermittent problems such as: Arrhythmias Ø Cardiac ischemia Ø Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 79

Holter Monitor (cont. ) Small battery-operated recorder box strapped to patient Patient keeps a Holter Monitor (cont. ) Small battery-operated recorder box strapped to patient Patient keeps a diary over the hours of use Physician reviews recording and tape, correlating findings Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 80

Placement of Holter Monitor Electrodes Copyright © 2010, 2006 by Saunders, an imprint of Placement of Holter Monitor Electrodes Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 81

Do’s and Don’ts of the Holter Monitor Copyright © 2010, 2006 by Saunders, an Do’s and Don’ts of the Holter Monitor Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 82

Procedure: Applying and Removing a Holter Monitor Demonstrate Copyright © 2010, 2006 by Saunders, Procedure: Applying and Removing a Holter Monitor Demonstrate Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 83

Cardiac Stress Testing (Treadmill) Exercise electrocardiography Ø Inexpensive, noninvasive procedure providing information about heart’s Cardiac Stress Testing (Treadmill) Exercise electrocardiography Ø Inexpensive, noninvasive procedure providing information about heart’s activity during periods of physical activity Ø Determines if heart is receiving enough blood during exercise or stress Shows imbalances between oxygen demand available supply Need signed consent form for procedure Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 84

Conclusion Accurate ECG tracing helps physician diagnose and treat patients Patient care is enhanced Conclusion Accurate ECG tracing helps physician diagnose and treat patients Patient care is enhanced when medical assistant is knowledgeable about operation of the ECG equipment Understanding the cardiac cycle and following the procedure for taking an ECG tracing will benefit the patient because accurate results will be produced Copyright © 2010, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 85