chapter 12 cardiopulmonary procedures. elsevier items and derived items © 2008 by saunders, an...

CHAPTER 12CHAPTER 12CARDIOPULMONARY PROCEDURES

Elsevier items and derived items © 2008 by Saunders, an imprint of Elsevier Inc. 2

PRETESTPRETEST

True or False1. 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.


PRETEST, CONT.PRETEST, CONT.

True or False6. 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.


Content OutlineContent Outline

1. Electrocardiograph: instrument used to record the electrical activity of the heart

2. Electrocardiogram (ECG): graphic representation of the electrical activity of the heart

Introduction to Electrocardiography


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




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




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




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




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


Three-Channel Electrocardiograph

Three-Channel Electrocardiograph


Structure of the HeartStructure of the Heart

1. Heart consists of four chambers

a. Upper chambers• Right atrium

• Left atrium

b. Lower chambers• Right ventricle

• Left ventricle


Structure of the HeartStructure of the Heart


Structure of the Heart, cont. 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



c. Pumped to the lungs• By way of pulmonary artery

– In lungs:

1) Picks up oxygen

2) Gives off CO2



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



f. Pumped into the aorta to be distributed to the body• Nourishes tissues with oxygen and nutrients


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


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




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




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




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


Cardiac CycleCardiac Cycle

1. Represents one complete heartbeat

2. Consists of:

a. Contraction of atria

b. Contraction of ventricles

c. Relaxation of entire heart


Cardiac CycleCardiac Cycle

3. ECG: records electrical activity that causes cardiac cycle to occur

4. ECG cycle: graphic representation of cardiac cycle


ECG CycleECG Cycle


WavesWaves

1. P wave

a. Represents electrical activity associated with contraction of atria

b. Known as: atrial depolarization


2. QRS complex (consists of Q, R, S waves)

a. Represents electrical activity associated with contraction of ventricles

b. Known as: ventricular depolarization


Waves, cont. Waves, cont.

3. T wave

a. Represents electrical recovery of the ventricles • Muscle cells are

recovering in preparation for another impulse

b. Ventricular repolarization


Waves, cont. Waves, cont.

4. U wave

a. Occasionally follows T wave

b. Small wave

c. May be associated with repolarization


Baseline, Segments, and Intervals

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


Baseline, Segments, and Intervals, cont.


2. ECG: divided into segments and intervals

a. Purpose: Interpretation and analysis of ECG




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


SegmentsSegments




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




5. Baseline (after T wave or U wave):

a. Period when entire heart returns to resting or polarized state


IntervalsIntervals


Electrocardiograph PaperElectrocardiograph 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


Electrocardiograph PaperElectrocardiograph Paper


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




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


Standardization of the Electrocardiograph

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


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)




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


Electrocardiograph LeadsElectrocardiograph 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


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


ElectrodeElectrode




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)




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


Electrocardiograph Components

Electrocardiograph Components




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)




8. Chest electrodes

a. Abbreviated V or C

b. Uses six chest electrodes




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


Bipolar LeadsBipolar 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


Bipolar Leads, cont. Bipolar Leads, cont.

b. Lead II: records heart's voltage between right arm and left leg


Bipolar Leads, cont.Bipolar Leads, cont.

c. Lead III: records heart's voltage between left arm and left leg


Bipolar Leads, cont. Bipolar Leads, cont.

3. Lead II: shows heart's rhythm more clearly than other leadsa. Rhythm strip: longer recording (12 inches) of lead

II• Often requested by physician

Courtesy the Burdick Corporation, Milton, Wisc.


Augmented LeadsAugmented 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


Augmented Leads, cont. 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



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



4. Leads I, II, III, aVR, aVL, and aVF

a. Records voltage from side to side and from top to bottom of heart


Chest LeadsChest Leads

1. V1, V2, V3, V4, V5, and V6a. 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


Chest LeadsChest Leads


What Would You Do?What Would You Not Do?



Maintenance of the ElectrocardiographMaintenance 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


Maintenance of the Electrocardiograph, cont.

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


Electrocardiograph Capabilities

Electrocardiograph Capabilities

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

Three-Channel Recording Capability


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


Three-Channel ECGThree-Channel ECG





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


TeletransmissionTeletransmission

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


Interpretive Electrocardiograph

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


Interpretive Electrocardiograph, cont.


3. Patient data: must be entered into electrocardiograph before running

a. Patient age

b. Sex

c. Height

d. Weight

e. Medications




4. Analysis printed at top of recording

a. Along with reason for interpretation

5. Results reviewed and further interpreted by physician


Interpretive ECGInterpretive ECG



ArtifactsArtifacts

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


Artifacts, cont. 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)


Artifacts, cont. 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


Muscle ArtifactMuscle Artifact

1. Characterized by: fuzzy, irregular baseline



Muscle Artifact, cont. Muscle Artifact, cont.

2. Due to:

a. Involuntary muscle movement (somatic tremor)

b. Voluntary muscle movement



3. Caused by:

a. Apprehensive patient• To correct:

– Reduce apprehension: relaxes muscles

1) Explain the procedure

2) Reassure patient that ECG is painless



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 colda) Can cause shivering



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


Wandering Baseline ArtifactWandering Baseline Artifact



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




– 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


Alternating Current ArtifactAlternating 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


Alternating Current Artifact, cont.


3. Appearance of AC artifact:

a. Small straight spiked lines that are consistent





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




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




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


Interrupted Baseline ArtifactInterrupted Baseline Artifact



Interrupted Baseline Artifact, cont.

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


Holter Monitor Electrocardiography

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


Holter Monitor Electrocardiography, cont.


4. Noninvasive procedure used to diagnose:

a. Cardiac rhythm abnormalities

b. Conduction abnormalities




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




6. Holter monitor consists of:

a. Electrodes placed on patient's chest




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


Holter Monitor SetupHolter Monitor Setup




7. Recorder held in a case worn on:

a. Belt, around patient's waist

b. Hung over patient's shoulder by strap




8. MA responsible for:

a. Preparing patient

b. Applying and removing monitor

c. Instructing patient for procedure


Holter Monitor Patient Guidelines

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


Holter Monitor Patient Guidelines, cont.

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


Electrode PlacementElectrode 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


Holter Monitor ElectrodeHolter Monitor Electrode


Electrode Placement, cont. Electrode Placement, cont.

2. Electrodes must be properly placed on patient's chest

a. Ensures accurate recording



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



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


Activity DiaryActivity 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



• Bowel movements

• Meals (including alcohol and caffeinated beverages)

• Sexual intercourse

• Medications consumed

• Sleep periods


Activity Diary, cont. Activity Diary, cont.

b. Examples of emotional states to record• Stress

• Anger

• Excitement


Activity Diary, cont. Activity Diary, cont.

2. Also record physical symptoms:

a. Dizziness

b. Fainting

c. Palpitations

d. Chest pain

e. Dyspnea

f. Nausea


Activity Diary, cont.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


Event Marker 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


Evaluating Results Evaluating Results

1. Holter monitor removed at end of 24-hour period

2. Recording is evaluated by:

a. Viewing and analyzing recording on a Holter scanning screen

b. Computer analysis


Evaluating ResultsEvaluating 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)


Cardiac DysrhythmiasCardiac 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


Cardiac Dysrhythmias, cont. 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


Cardiac Dysrhythmias, cont.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


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




From Huang S, et al: Coronary care nursing, Philadelphia, 1989, Saunders.


Atrial Premature Contraction (APC), cont.

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


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


Paroxysmal Atrial Tachycardia (PAT), cont.


f. Patient experiences• Sudden pounding or fluttering of chest

• Weakness and breathlessness

• Acute apprehension

• Occasionally syncope




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


Atrial FlutterAtrial 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


Atrial Flutter, cont.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


Atrial Flutter, cont. 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


Atrial Flutter, cont.Atrial Flutter, cont.

• Acute myocardial infarction

• Chronic lung disease

• Hypertensive heart disease

• Pulmonary emboli

• Patients who have undergone cardiac surgery


Atrial Fibrillation (AF)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)


Atrial Fibrillation (AF)Atrial Fibrillation (AF)



Atrial Fibrillation (AF), cont. Atrial Fibrillation (AF), cont.

2. Clinical Aspects

a. Occurs in healthy individuals• Caused by stress, excessive alcohol

consumption, vomiting


Atrial Fibrillation (AF), cont.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


Atrial Fibrillation (AF), cont.Atrial Fibrillation (AF), cont.

• Individuals over 50: may be caused by

– Coronary artery disease

– Mitral valve disease

1) Hypertension heart disease


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


Premature Ventricular Contraction (PVC), cont.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


Premature Ventricular Contraction (PVC), cont. Premature Ventricular


2. Clinical Aspects

a. Seen in normal individuals in all age groups

b. Caused by:• Anxiety

• Smoking

• Caffeine

• Alcohol

• Certain medications (e.g., epinephrine)


Premature Ventricular Contraction (PVC), cont.Premature Ventricular


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


Ventricular Tachycardia (VT)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


Ventricular Tachycardia (VT), cont.


c. QRS complexes are bizarre and widened

d. No P waves present





e. Sustained VT: life-threatening• Prevents adequate filling time for heart

• May degenerate into ventricular fibrillation and cardiac arrest




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


Ventricular Fibrillation (VF)Ventricular Fibrillation (VF)

1. Descriptiona. 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


Ventricular Fibrillation (VF)Ventricular Fibrillation (VF)



Ventricular Fibrillation (VF), cont.


f. No effective ventricular pumping action

g. Must be treated immediately

h. Can lead to sudden death




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


Pulmonary Function TestsPulmonary Function Tests

1. Purpose of PFT: To assess lung functioning

2. Assists in detection of pulmonary disease


Pulmonary Function Tests, cont.

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


SpirometrySpirometry

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


Spirometry, cont.Spirometry, cont.

3. Considered a screening test

a. Abnormal results: require additional PFT tests


Spirometry, cont.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


Spirometry, cont. 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


Spirometry Test ResultsSpirometry 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


SpirometrySpirometry


Spirometry Test Results, cont. 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



• 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 instructionsa) 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



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



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



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%


Spirometry ParametersSpirometry Parameters



5. Evaluating the Results

a. Demographic factors used to evaluate results entered into the machine:• Age

• Sex

• Weight

• Height



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


Predicted and Measured Values

Predicted and Measured Values


Patient Preparation 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


Patient Preparation, cont.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


Calibration 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)


Post-Bronchodilator Spirometry

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


Post-Bronchodilator Spirometry, cont.

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


POSTTESTPOSTTEST

True or False1. 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.


POSTTEST, CONT.POSTTEST, CONT.

True or False6. 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.

chapter 12 cardiopulmonary procedures. elsevier items and derived items © 2008 by saunders, an...

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