Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
CHAPTER 12 CARDIOPULMONARY PROCEDURES PRETEST True or False 1. Blood enters the right atrium from the superior and inferior vena cava. 2. The cardiac cycle represents one complete heartbeat. 3. A standard electrocardiogram consists of 10 leads. 4. An electrolyte facilitates the transmission of electrical impulses. 5. Leads V1 through V6 are known as the augmented leads. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 2 PRETEST, CONT. True or False 6. Electrodes that are too loose can cause an alternating current artifact. 7. When running an ECG, the medical assistant should work on the left side of the patient. 8. An ECG that it within normal limits is said to have a normal sinus rhythm. 9. The most serious cardiac dysrhythmia is atrial fibrillation. 10. The purpose of a pulmonary function test is to assess cardiac functioning. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 3 Content Outline Introduction to Electrocardiography 1. Electrocardiograph: instrument used to record the electrical activity of the heart 2. Electrocardiogram (ECG): graphic representation of the electrical activity of the heart Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 4 Introduction to Electrocardiography, cont. 3. Purpose a. Detect an abnormal cardiac rhythm (dysrhythmia) b. Help diagnose damage to heart caused by myocardial infarction c. Assess the effect on the heart of digitalis or other cardiac drugs d. Determine the presence of electrolyte disturbances Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 5 Introduction to Electrocardiography, cont. e. Assess progress of rheumatic fever f. Determine presence of hypertrophy of the heart chambers g. Use before surgery to assess cardiac risk during surgery Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 6 Introduction to Electrocardiography, cont. 4. ECG cannot detect all cardiovascular disorders a. Cannot always detect impending heart disease 5. Used to assess cardiac functioning a. Along with other diagnostic/laboratory tests Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 7 Introduction to Electrocardiography, cont. 6. MA responsible for running ECG, which includes: a. Preparation of patient b. Operation of electrocardiograph c. Identification and elimination of artifacts d. Labeling the completed ECG e. Care and maintenance of electrocardiograph Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 8 Introduction to Electrocardiography, cont. 7. ECG machine formats: a. Single-channel format: one lead recorded at a time b. Three-channel format: three leads recorded at one time • Most offices use Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 9 Three-Channel Electrocardiograph Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 10 Structure of the Heart 1. Heart consists of four chambers a. Upper chambers • Right atrium • Left atrium b. Lower chambers • Right ventricle • Left ventricle Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 11 Structure of the Heart Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 12 Structure of the Heart, cont. 2. Pathway of blood through the heart a. Blood enters right atrium: from superior and inferior vena cava • Brought back to heart after circulating in body • Deoxygenated: contains very little oxygen and high in carbon dioxide (CO2) b. Enters right ventricle Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 13 Structure of the Heart, cont. c. Pumped to the lungs • By way of pulmonary artery – In lungs: 1) Picks up oxygen 2) Gives off CO2 Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 14 Structure of the Heart, cont. d. Returns to the left atrium of heart • By way of pulmonary veins e. Enters left ventricle • Most powerful chamber of the heart – Pumps blood to entire body Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 15 Structure of the Heart, cont. f. Pumped into the aorta to be distributed to the body • Nourishes tissues with oxygen and nutrients Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 16 Conduction System of the Heart 1. Sinoatrial node (SA node) a. Located in upper portion of right atrium b. Consists of: knot of modified myocardial cells • Able to send out an electrical impulse – Without an external nerve stimulus c. Initiates and regulates heartbeat Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 17 Conduction System of the Heart Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 18 Conduction System of the Heart, cont. 2. Path of impulse from SA node a. Electrical impulse discharged by SA node b. Impulse distributed to right and left atria: causes atria to contract • Blood forced through cuspid valves and into ventricles Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 19 Conduction System of the Heart, cont. c. Impulse picked up by atrioventricular (AV) node • Knot of modified myocardium – Located at base of right atrium d. AV node delays impulse momentarily • Gives ventricles a chance to fill with blood Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 20 Conduction System of the Heart, cont. e. Impulse transmitted to bundle of His • Bundle of His is divided into right and left bundle branches f. Bundle branches: relays impulse to the Purkinje fibers Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 21 Conduction System of the Heart, cont. g. Purkinje fibers: distributes impulse evenly to right and left ventricles • Causes ventricles to contract – Forces blood out of ventricles: into pulmonary artery and aorta h. Entire heart relaxes momentarily i. New impulse initiated by SA node j. Cycle repeats Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 22 Conduction System of the Heart Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 23 Cardiac Cycle 1. Represents one complete heartbeat 2. Consists of: a. Contraction of atria b. Contraction of ventricles c. Relaxation of entire heart Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 24 Cardiac Cycle 3. ECG: records electrical activity that causes cardiac cycle to occur 4. ECG cycle: graphic representation of cardiac cycle Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 25 ECG Cycle Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 26 Waves 1. P wave a. Represents electrical activity associated with contraction of atria b. Known as: atrial depolarization Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 27 2. QRS complex (consists of Q, R, S waves) a. Represents electrical activity associated with contraction of ventricles b. Known as: ventricular depolarization Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 28 Waves, cont. 3. T wave a. Represents electrical recovery of the ventricles • Muscle cells are recovering in preparation for another impulse b. Ventricular repolarization Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 29 Waves, cont. 4. U wave a. Occasionally follows T wave b. Small wave c. May be associated with repolarization Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 30 Baseline, Segments, and Intervals 1. Baseline a. Flat, horizontal line that separates various waves b. Waves deflect either upward or downward from baseline: • Positive deflection: wave deflects upward • Negative deflection: wave deflects downward Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 31 Baseline, Segments, and Intervals, cont. 2. ECG: divided into segments and intervals a. Purpose: Interpretation and analysis of ECG Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 32 Baseline, Segments, and Intervals, cont. 3. Segment: portion of the ECG between two waves a. P-R segment: • From the end of atrial depolarization to the beginning of ventricular depolarization – Represents time needed for impulse to be delayed at AV node b. S-T segment: • From the end of ventricular depolarization to the beginning of repolarization of ventricles Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 33 Segments Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 34 Baseline, Segments, and Intervals, cont. 4. Interval: length of a wave or length of wave with a segment a. P-R interval: • From the beginning of atrial depolarization to the beginning of ventricular depolarization b. Q-T interval: • From the beginning of ventricular depolarization to the end of repolarization of the ventricles Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 35 Baseline, Segments, and Intervals, cont. 5. Baseline (after T wave or U wave): a. Period when entire heart returns to resting or polarized state Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 36 Intervals Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 37 Electrocardiograph Paper 1. Paper divided into two sets of squares a. Small square: 1 mm high and 1 mm wide b. Large square: 5 mm high and 5 mm wide • Each large square made up of 25 small squares Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 38 Electrocardiograph Paper Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 39 Electrocardiograph Paper, cont. 2. Physician uses graph to measures waves, intervals, and segments a. Determines if ECG is within normal limits 3. Paper consists of: a. Black or blue base with white plastic coating b. Black or red graph printed on top of coating Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 40 Electrocardiograph Paper, cont. 4. Heated stylus moves over heat-sensitive paper a. Melts away plastic coating b. Results in recording of the ECG cycles 5. Paper is also pressure-sensitive a. Handle carefully to avoid making impressions • May interferes with proper reading of ECG Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 41 Standardization of the Electrocardiograph 1. Electrocardiograph must be standardized for every recording a. Quality control measure • Ensures an accurate and reliable recording • Means ECG run on one electrocardiograph: compares in accuracy with a recording run on another machine Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 42 Standardization of the Electrocardiograph, cont. 2. Normal standardization mark: a. Height: 10 mm (10 small squares) b. Width: approximately 2 mm wide (2 small squares) Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 43 Standardization of the Electrocardiograph, cont. 3. Three-channel machine: automatically records standardization marks on recording 4. If standardization mark is more or less than 10 mm high: a. Machine must be adjusted b. Consult operating manual for adjustment info Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 44 Electrocardiograph Leads 1. Consists of 12 leads 2. Each lead a. Provides an electrical "photograph" of heart's activity from a different angle b. Results in 12 "photographs" of the heart • Facilitates thorough interpretation of heart's activity Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 45 Electrocardiograph Leads, cont. 3. Electrode a. Made of a substance that is a good conductor of electricity b. Picks up electrical impulses given off by the heart • Conducts impulse into machine by lead wires Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 46 Electrode Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 47 Electrocardiograph Leads, cont. 4. Amplifier: device located in machine that amplifies the electrical impulses a. Electrical impulses given off by the heart: very small • Must be made larger (amplified) Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 48 Electrocardiograph Leads, cont. 5. Galvanometer: changes amplified voltages into mechanical motion 6. Stylus (heated): a. Records heart tracing on ECG paper • By melting plastic coating on ECG paper Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 49 Electrocardiograph Components Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 50 Electrocardiograph Leads, cont. 7. Limb electrodes a. Right arm (RA) b. Left arm (LA) c. Right leg (RL): ground • Not used for recording • Serves as an electrical reference point d. Left leg (LL) Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 51 Electrocardiograph Leads, cont. 8. Chest electrodes a. Abbreviated V or C b. Uses six chest electrodes Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 52 Electrocardiograph Leads, cont. 9. Electrode used with three-channel recording a. Disposable b. Consists of self-adhesive tab • Contains an electrolyte – Electrolyte: facilitates transmission of an electrical impulse c. Electrode applied to skin using adhesive backing • Thrown away after use Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 53 Bipolar Leads 1. Leads I, II, III 2. Each bipolar lead: uses two limb electrodes to record electrical activity of heart a. Lead I: records heart's voltage between right arm and left arm Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 54 Bipolar Leads, cont. b. Lead II: records heart's voltage between right arm and left leg Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 55 Bipolar Leads, cont. c. Lead III: records heart's voltage between left arm and left leg Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 56 Bipolar Leads, cont. 3. Lead II: shows heart's rhythm more clearly than other leads a. Rhythm strip: longer recording (12 inches) of lead II • Often requested by physician Courtesy the Burdick Corporation, Milton, Wisc. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 57 Augmented Leads 1. aVR (augmented voltage—right arm) a. Records heart's voltage between: • Right arm electrode and a central point between left arm and left leg Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 58 Augmented Leads, cont. 2. aVL (augmented voltage—left arm) a. Records heart's voltage between: • Left arm electrode and a central point between right arm and left leg Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 59 Augmented Leads, cont. 3. aVF (augmented voltage: left leg or foot) a. Records heart's voltage between: • Left leg electrode and a central point between right arm and left arm Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 60 Augmented Leads, cont. 4. Leads I, II, III, aVR, aVL, and aVF a. Records voltage from side to side and from top to bottom of heart Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 61 Chest Leads 1. V1, V2, V3, V4, V5, and V6 a. Record heart's voltage from front to back of heart • From a central point "inside" the heart: to a point on the chest wall – Where each chest electrode is placed 2. Leads must be properly located: to ensure an accurate and reliable recording 3. Normally ECG is recorded with paper moving at speed of 25 mm/second Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 62 Chest Leads Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 63 What Would You Do? What Would You Not Do? Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 64 What Would You Do? What Would You Not Do? Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 65 Maintenance of the Electrocardiograph 1. Casing a. Clean frequently • Use a mild detergent and soft cloth to remove dust and dirt • Do not use solvents or abrasives – Can damage finish of casing Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 66 Maintenance of the Electrocardiograph, cont. 2. Patient cable, lead wires, power cord a. Clean with a cloth saturated with a disinfectant b. Never immerse these items in cleaning solution • Can damage them Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 67 Electrocardiograph Capabilities Three-Channel Recording Capability 1. Records electrical activity of three leads simultaneously a. (Single-channel: records only one lead at a time) 2. Advantage a. ECG can be run in less time Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 68 Three-Channel Recording Capability, cont. 3. Leads recorded simultaneously a. I, II, III b. aVR, aVL, aVF c. V1, V2, V3 d. V4, V5, V6 Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 69 Three-Channel ECG Courtesy the Burdick Corporation, Milton, Wisc. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 70 Three-Channel Recording Capability, cont. 4. Requires three-channel recording paper (8½ by 11 inches) a. Printout: fits easily into patient's chart 5. Most have copy capability a. Quickly produces recording of last ECG recorded Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 71 Teletransmission 1. Transmits recording over phone line to ECG data interpretation site 2. Recording interpreted by cardiologist a. Computer analysis may also be performed 3. Interpretation and ECG recording: electronically transmitted to sending office same day Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 72 Interpretive Electrocardiograph 1. Built-in computer program a. Analyzes recording as it is being run 2. Provides immediate information on heart's activity a. Leads to earlier diagnosis and treatment Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 73 Interpretive Electrocardiograph, cont. 3. Patient data: must be entered into electrocardiograph before running a. Patient age b. Sex c. Height d. Weight e. Medications Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 74 Interpretive Electrocardiograph, cont. 4. Analysis printed at top of recording a. Along with reason for interpretation 5. Results reviewed and further interpreted by physician Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 75 Interpretive ECG Courtesy the Burdick Corporation, Milton, Wisc. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 76 Artifacts 1. Important to produce a clear and concise ECG a. Can be easily read and interpreted by physician 2. Occasionally artifacts appear in recording a. Artifact: additional electrical activity picked up by electrocardiograph • Interferes with normal appearance of ECG cycles Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 77 Artifacts, cont. 3. Artifacts must be identified and corrected by the MA 4. Most common artifacts: a. Muscle b. Wandering baseline c. Alternating current (AC) Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 78 Artifacts, cont. 5. If unable to correct artifacts: machine may be broken a. Contact service technician with following info: • What has already been done to locate and correct problem • Leads in which artifact occurs • Sample of the artifact Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 79 Muscle Artifact 1. Characterized by: fuzzy, irregular baseline Courtesy the Burdick Corporation, Milton, Wisc. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 80 Muscle Artifact, cont. 2. Due to: a. Involuntary muscle movement (somatic tremor) b. Voluntary muscle movement Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 81 Muscle Artifact, cont. 3. Caused by: a. Apprehensive patient • To correct: – Reduce apprehension: relaxes muscles 1) Explain the procedure 2) Reassure patient that ECG is painless Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 82 Muscle Artifact, cont. b. Patient discomfort • To correct: make patient more comfortable – Make sure table is wide enough to support patient's arms and legs – Place pillow under patient's head – Make sure room temperature is comfortable for patient: 1) Patient has removed clothing: may be cold a) Can cause shivering Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 83 Muscle Artifact, cont. c. Patient movement • To correct: – Instruct patient to lie still and not to talk d. Physical condition (e.g., Parkinson's disease) • To correct: – Try to record when tremor is at a minimum Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 84 Wandering Baseline Artifact Courtesy the Burdick Corporation, Milton, Wisc. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 85 Wandering Baseline Artifact, cont. 1. Caused by: a. Loose electrodes • To correct: – Make sure electrodes are attached firmly to patient's skin – If electrode pulls loose: 1) Reattach with tape 2) Replace with a new electrode Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 86 Wandering Baseline Artifact, cont. – Make sure clips are firmly attached to electrodes – Make sure patient cable is well-supported on patient's abdomen or table 1) Do not allow cable to dangle b. Body creams, oils, or lotions on skin at electrode application site • To correct: – Remove by rubbing with alcohol using friction Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 87 Alternating Current Artifact 1. Due to electrical interference 2. Can leak out: from power used by electrical appliances in room a. May be picked up by patient • Are carried into machine: – Results in AC artifact Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 88 Alternating Current Artifact, cont. 3. Appearance of AC artifact: a. Small straight spiked lines that are consistent Courtesy the Burdick Corporation, Milton, Wisc. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 89 Alternating Current Artifact, cont. 4. Caused by: a. Lead wires not following body contour • Dangling lead wires pick up AC • To correct: – Arrange lead wires to follow body contour and to lie flat Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 90 Alternating Current Artifact, cont. b. Other electrical equipment in room: may leak AC • To correct: – Unplug nearby electrical equipment (lamps, autoclave, electrically powered examining table) c. Wiring in walls, ceiling, floors • To correct: – Move patient table away from walls Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 91 Alternating Current Artifact, cont. d. Improper grounding of the electrocardiograph • Machine is automatically grounded when plugged in (by three-prong plug) • Make sure plug is securely in wall outlet • RL electrode picks up AC from patient and carries it into machine – AC is then carried away by grounding system of machine Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 92 Interrupted Baseline Artifact Courtesy the Burdick Corporation, Milton, Wisc. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 93 Interrupted Baseline Artifact, cont. 1. Caused by: a. Metal tip of lead wire becoming detached from alligator clip • To correct: – Reattach lead to alligator clip b. Broken patient cable • To correct – Replace patient cable Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 94 Holter Monitor Electrocardiography 1. Portable ambulatory monitoring system 2. Records cardiac activity of patient for 24 hours 3. Patient maintains daily activities while being monitored Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 95 Holter Monitor Electrocardiography, cont. 4. Noninvasive procedure used to diagnose: a. Cardiac rhythm abnormalities b. Conduction abnormalities Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 96 Holter Monitor Electrocardiography, cont. 5. Specific uses: a. Evaluate unexplained syncope b. Discover intermittent cardiac dysrhythmias not picked up on ECG c. Assess effectiveness of antidysrhythmic medications • Examples: – Digitalis – Antianginal medications d. Assess effectiveness of artificial pacemaker Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 97 Holter Monitor Electrocardiography, cont. 6. Holter monitor consists of: a. Electrodes placed on patient's chest Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 98 Holter Monitor Electrocardiography, cont. b. Portable recorder: continually monitors heart's activity • Types: – Magnetic tape recorder: uses a magnetic tape to record heart's activity – Computerized digital recorder: uses a compact flash memory card to record to heart's activity Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 99 Holter Monitor Setup Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 100 Holter Monitor Electrocardiography, cont. 7. Recorder held in a case worn on: a. Belt, around patient's waist b. Hung over patient's shoulder by strap Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 101 Holter Monitor Electrocardiography, cont. 8. MA responsible for: a. Preparing patient b. Applying and removing monitor c. Instructing patient for procedure Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 102 Holter Monitor Patient Guidelines 9. Holter Monitor Patient Guidelines a. Keep electrodes and monitor dry • Do not shower, bathe, or swim while wearing monitor – Ensures accurate recording – Prevents damage to recorder b. Do not touch or move the electrodes • Prevents occurrence of artifacts on recording Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 103 Holter Monitor Patient Guidelines, cont. c. Do not handle monitor or take out of case d. Depress event marker only momentarily when symptom occurs • Overuse of marker: causes masking of ECG signals e. Do not use an electric blanket while wearing monitor Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 104 Electrode Placement 1. Electrode consists of: a. Plastic electrode plate with adhesive backing b. Central sponge pad • Contains an electrolyte gel c. Electrode is disposable: discard after use Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 105 Holter Monitor Electrode Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 106 Electrode Placement, cont. 2. Electrodes must be properly placed on patient's chest a. Ensures accurate recording Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 107 Electrode Placement, cont. 3. Check monitor after hooking up patient: a. Purpose: To make sure a clear signal is being relayed from electrodes to recorder b. Procedure for checking monitor: • Attach one end of a test cable to recorder • Attach other end to ECG machine • Record a baseline strip • Observe for correct waveforms and absence of artifacts Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 108 Electrode Placement, cont. 4. If problem occurs: a. Patient may not be hooked up properly b. Malfunction of cable or lead may be present c. Reconnect leads and reposition electrodes and check again • If problem still exists: monitor may need to be repaired Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 109 Activity Diary 1. Patient uses to record all activities/emotional states during monitoring period a. Examples of activities to record: • Physical exercise • Walking up/down stairs • Smoking Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 110 Activity Diary • Bowel movements • Meals (including alcohol and caffeinated beverages) • Sexual intercourse • Medications consumed • Sleep periods Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 111 Activity Diary, cont. b. Examples of emotional states to record • Stress • Anger • Excitement Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 112 Activity Diary, cont. 2. Also record physical symptoms: a. Dizziness b. Fainting c. Palpitations d. Chest pain e. Dyspnea f. Nausea Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 113 Activity Diary, cont. 3. Include in recording: a. Time of occurrence 4. Purpose of diary: a. Dysrhythmia on tape compared with patient's diary • To correlate symptoms with cardiac activity Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 114 Activity Diary Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 115 Event Marker 1. Most monitors have an event marker a. Used with diary for patient evaluation 2. Patient depresses marker (momentarily) when experiencing a symptom a. Electronic signal placed on magnetic tape or flash memory card 3. Alerts technician to significant event on recording Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 116 Evaluating Results 1. Holter monitor removed at end of 24hour period 2. Recording is evaluated by: a. Viewing and analyzing recording on a Holter scanning screen b. Computer analysis Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 117 Evaluating Results 3. Printouts of the recording: can be obtained for further study 4. Physician provided with written report a. Along with selected printouts of abnormal cardiac activity (e.g., dysrhythmias) Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 118 Cardiac Dysrhythmias 1. Normal ECG: consists of P wave, QRS complex, and T wave a. Repeats in a regular pattern (see Figure 12-4) 2. Normal sinus rhythm: ECG that is within normal limits a. Waves, intervals, segments, cardiac rate: fall within normal range Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 119 Cardiac Dysrhythmias, cont. 3. Normal heart rate range: 60 to 100 beats per minute (bpm) 4. Sinus bradycardia: Below 60 bpm 5. Sinus tachycardia: Above 100 bpm Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 120 Cardiac Dysrhythmias, cont. 6. Cardiac abnormalities include: a. Extra beats b. Abnormal rhythm (dysrhythmia) c. Abnormal heart rate 7. MA should be able to identify dysrhythmias on ECG a. Alert physician Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 121 Atrial Premature Contraction (APC) 1. Description a. Beat that comes before next normal beat is due b. P wave has a different shape from P wave of normal beat c. Normal QRS complex and T wave Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 122 Atrial Premature Contraction (APC) From Huang S, et al: Coronary care nursing, Philadelphia, 1989, Saunders. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 123 Atrial Premature Contraction (APC), cont. 2. Clinical Aspects a. Common in healthy individuals b. Often caused by intake of stimulants (caffeine, tobacco) c. Can also be associated with: • Serious atrial dysrhythmias • Structural heart disease Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 124 Paroxysmal Atrial Tachycardia (PAT) 1. Description a. Abrupt episode of tachycardia b. Heart rate: 150 to 250 bpm c. Sudden onset and termination d. Only last few seconds; then heart rate returns to normal e. ECG cycles are very close together: due to increased heart rate Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 125 Paroxysmal Atrial Tachycardia (PAT) From Huang S, et al: Coronary care nursing, Philadelphia, 1989, Saunders. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 126 Paroxysmal Atrial Tachycardia (PAT), cont. f. Patient experiences • Sudden pounding or fluttering of chest • Weakness and breathlessness • Acute apprehension • Occasionally syncope Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 127 Paroxysmal Atrial Tachycardia (PAT), cont. 2. Clinical Aspects a. One of most common rhythm disorders b. Often occurs in healthy patients • Especially young adults with normal hearts c. Can also occur in patients with organic heart disease Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 128 Atrial Flutter 1. Description a. Rapid regular fluttering of atrium b. Heart rate: 250 to 350 bpm c. More than one P wave precedes QRS complex • Can range from 1 to 8 Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 129 Atrial Flutter, cont. d. P wave appears as saw-toothed spikes between QRS complexes e. QRS complexes are normal f. T wave usually lost in P waves Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 130 Atrial Flutter, cont. 2. Clinical Aspects a. Rarely occurs in healthy individuals b. Found in patients with underlying heart disease c. Can occur in patients with: • Mitral valve disease • Coronary artery disease Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 131 Atrial Flutter, cont. • Acute myocardial infarction • Chronic lung disease • Hypertensive heart disease • Pulmonary emboli • Patients who have undergone cardiac surgery Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 132 Atrial Fibrillation (AF) 1. Description a. P waves have no definite pattern or shape • Appear as irregular, wavy undulations between QRS complexes b. QRS complexes are normal but do not have a definite pattern c. Atria contract 400 to 500 times per minute d. Ventricular rate may be normal or rapid (150 to180 bpm) Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 133 Atrial Fibrillation (AF) From Huang S, et al: Coronary care nursing, Philadelphia, 1989, Saunders. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 134 Atrial Fibrillation (AF), cont. 2. Clinical Aspects a. Occurs in healthy individuals • Caused by stress, excessive alcohol consumption, vomiting Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 135 Atrial Fibrillation (AF), cont. b. Can occur in patients with heart disease • Individuals under 50: may be caused by – Congenital heart disease – Rheumatic heart disease with mitral valve involvement Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 136 Atrial Fibrillation (AF), cont. • Individuals over 50: may be caused by – Coronary artery disease – Mitral valve disease 1) Hypertension heart disease Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 137 Premature Ventricular Contraction (PVC) 1. Description a. Most common rhythm disturbance seen on ECG b. Beat comes early in the cycle • Not preceded by a P wave Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 138 Premature Ventricular Contraction (PVC), cont. c. Wide and distorted QRS complex • Easily stands out on ECG d. T wave opposite in direction to R wave e. Baseline distance after PVC: usually longer than normal • Means PVC is followed by a pause before next normal beat Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 139 Premature Ventricular Contraction (PVC) From Huang S, et al: Coronary care nursing, Philadelphia, 1989, Saunders. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 140 Premature Ventricular Contraction (PVC), cont. 2. Clinical Aspects a. Seen in normal individuals in all age groups b. Caused by: • Anxiety • Alcohol • Smoking • Certain medications (e.g., epinephrine) • Caffeine Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 141 Premature Ventricular Contraction (PVC), cont. c. Can also occur with any type of heart disease d. Seen most often with: • Hypertensive heart disease • Ischemic heart disease • Lung disease with hypoxia • Digitalis toxicity • Mitral valve prolapse Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 142 Ventricular Tachycardia (VT) 1. Description a. Series of three or more consecutive PVCs • Occur at a rate of 150 to 250 bpm b. May occur suddenly and last for short time • Or may last for a long time Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 143 Ventricular Tachycardia (VT), cont. c. QRS complexes are bizarre and widened d. No P waves present From Huang S, et al: Coronary care nursing, Philadelphia, 1989, Saunders. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 144 Ventricular Tachycardia (VT), cont. e. Sustained VT: life-threatening • Prevents adequate filling time for heart • May degenerate into ventricular fibrillation and cardiac arrest Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 145 Ventricular Tachycardia (VT), cont. 2. Clinical Aspects a. Usually see in patients with acute or chronic heart disease b. Indicative of coronary artery disease c. Also occurs as a complication of myocardial infarction Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 146 Ventricular Fibrillation (VF) 1. Description a. Most serious dysrhythmia b. Ventricles do not beat in a coordinated manner • Instead they twitch or fibrillate c. Virtually no blood is ejected into systemic circulation d. Appears as irregular, chaotic undulations of baseline on ECG e. No recognizable P waves, QRS complexes, or T waves Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 147 Ventricular Fibrillation (VF) From Huang S, et al: Coronary care nursing, Philadelphia, 1989, Saunders. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 148 Ventricular Fibrillation (VF), cont. f. No effective ventricular pumping action g. Must be treated immediately h. Can lead to sudden death Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 149 Ventricular Fibrillation (VF), cont. 2. Clinical Aspects a. Most common cause: acute myocardial infarction b. Can also occur in patients with: • Organic heart disease • Cardiac dysrhythmias c. May be preceded by PVCs or ventricular tachycardia or may occur spontaneously Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 150 What Would You Do? What Would You Not Do? Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 151 What Would You Do? What Would You Not Do? Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 152 Pulmonary Function Tests 1. Purpose of PFT: To assess lung functioning 2. Assists in detection of pulmonary disease Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 153 Pulmonary Function Tests, cont. 3. PFT tests include: a. Spirometry b. Lung volumes c. Diffusion capacity d. Arterial blood gas studies e. Pulse oximetry f. Cardiopulmonary exercise tests Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 154 Spirometry 1. Noninvasive screening test often performed in medical office 2. Spirometer: computerized electronic instrument a. Measures: • Amount of air that is expelled from the lungs • Rate at which air is expelled b. Report printed out as a table and/or graph Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 155 Spirometry, cont. 3. Considered a screening test a. Abnormal results: require additional PFT tests Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 156 Spirometry, cont. 4. Indications for performing spirometry a. Patients who exhibit symptoms of lung dysfunction (e.g., dyspnea) b. Patients at high risk for lung disease • Smoking • Exposure to environmental pollutants – Coal dust – Asbestos – Exhaust fumes Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 157 Spirometry, cont. c. Patients with lung disease • Asthma • Chronic bronchitis • Emphysema d. Patients who will undergo surgery: • To assess probable lung performance during an operation e. Evaluation of lung disability/impairment for a compensation program (e.g., coal miner) • Provide a number of measurements to assess lung function Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 158 Spirometry Test Results 1. Spirometry: provides numerous measurements to assess lung function 2. Forced Vital Capacity (FVC): Maximum volume of air that can be expired when patient exhales as forcefully and rapidly as possible for as long as possible (measured in liters) a. FVC breathing maneuver • Patient takes a deep breath until lungs are completely full • Patient blows all air out of lungs into a mouthpiece – As hard and fast as possible until no more air can be expelled Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 159 Spirometry Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 160 Spirometry Test Results, cont. • To be considered an adequate test: – Patient must forcibly blow out all air and continue smooth, continuous exhaling for 6 seconds Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 161 Spirometry Test Results, cont. • Minimum of three acceptable efforts must be obtained – Some patients have trouble performing breathing maneuver due to: 1) Physical impairment 2) Poor motivation 3) Do not understand instructions a) Be patient and work with patient to help perform maneuver b) If unable to perform maneuver after eight attempts: discontinue testing o Fatigue may affect accuracy of results Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 162 Spirometry Test Results, cont. 3. Forced Expiratory Volume after 1 Second (FEV1): Volume of air that is forcefully exhaled during first second of the FVC breathing maneuver a. Automatically determined by the spirometer Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 163 Spirometry Test Results, cont. 4. FEV1/FVC Ratio: Comparison of FEV1 with FVC a. Patient with healthy lungs: 70% to 75% of air exhaled (FVC) is exhaled in the first second (FEV1) of breathing maneuver • Expressed as a percentage • Example: patient with healthy lungs may have ratio of 85% – Means that 85% of exhaled air was exhaled during first second of breathing maneuver Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 164 Spirometry Test Results, cont. b. Patients with chronic obstructive pulmonary disease (COPD): ratio falls below 70% to 75% • Patient unable to move exhaled air out of lungs because of an obstruction to the airflow – Examples: Inflammation; damaged lung tissue c. Categories of airflow obstruction • Mild obstruction: 61% to 69% • Moderate obstruction: 45% to 60% • Severe obstruction: Less than 45% Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 165 Spirometry Parameters Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 166 Spirometry Test Results, cont. 5. Evaluating the Results a. Demographic factors used to evaluate results entered into the machine: • Age • Sex • Weight • Height Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 167 Spirometry Test Results, cont. b. Based on demographic factors: computer calculates predicted values. • Predicted value: What the results should be for a patient with healthy lungs c. Once test run: physician compares measured values with predicted values • Values are printed out on the spirometry report • Assists physician in detecting pulmonary disease Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 168 Predicted and Measured Values Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 169 Patient Preparation 6. Patient Preparation a. Do not eat heavy meal for 8 hours before test • Full stomach: interferes with performing breathing maneuver b. Stop smoking at least 8 hours before test c. Do not take bronchodilators 4 hours before test Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 170 Patient Preparation, cont. d. Do not engage in strenuous activity 4 hours before test e. Wear loose, nonrestrictive clothing: keeps chest area free • Easier to perform breathing maneuver Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 171 Calibration 7. Calibration of the spirometer a. Perform each day machine is used b. Known quality of air injected into spirometer c. 3-L spirometry syringe: used to inject 3 L of air into machine d. Output should read 3 L e. Reading should not vary more than 3% f. If not calibrated properly: adjust machine (consult operating manual) Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 172 Post-Bronchodilator Spirometry 1. Ordered when results of spirometry indicate an obstruction 2. How performed: a. Patient inhales a bronchodilator b. Spirometry test is run 10 to 15 minutes later Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 173 Post-Bronchodilator Spirometry, cont. 3. Purpose: informs physician how treatment will work in patients with obstructed airway a. If FVC or FEV1 increases by at least 15%: result is reported as positive for bronchodilator responsiveness • Means the obstruction may be reversible or partially reversible with medications Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 174 What Would You Do? What Would You Not Do? Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 175 What Would You Do? What Would You Not Do? Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 176 POSTTEST True or False 1. An electrocardiogram is a recording of the electrical activity of the heart. 2. The AV node sets the pace of the heart. 3. The P wave represents the contraction of the ventricles. 4. If the electrocardiograph is standardized, the standardization mark will be 20 mm high. 5. Electrocardiograms are normally recorded with the paper moving at a speed of 25 mm/sec. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 177 POSTTEST, CONT. True or False 6. A muscle artifact can be identified by its fuzzy, irregular baseline. 7. The patient is permitted to shower while wearing a Holter monitor. 8. A patient with a PAT dysrhythmia often experiences weakness and acute apprehension. 9. A spirometer measures how much air is exhaled by the lungs and how fast it is exhaled. 10. Spirometry can be used to assess a patient with emphysema. Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 178