Module 13: EKG and Cardiovascular Testing

Question 1

Stress testing overview, role of medical assistant, and risks

Answer 1

Patients are attached to heart monitoring equipment while they exercise on stationary bike or treadmill. They might receive special blood flow dye thalium.

The medical assistant attaches leads and monitors vital signs throughout the procedure. They can be responsible for patient education; including pre- and post-procedure instructions

Potential risk of cardiac arrest

Question 2

Holter monitoring/event monitoring overview, role of medical assistant, instructions to patient

Answer 2

AKA ambulatory monitoring, common in cardiology.

Instructions:
Patients assume their normal activities and keep a diary of those activities.
o) press the event monitor if they experience any cardiac symptoms or neurological symptoms.
o) do not move the electrodes.
o) avoid showers/water
o) avoid exposure to electrical forces
o) wear for 24-48 hrs

The medical assistant is responsible for attaching electrodes to trunk and providing patient education

Question 3

Role of the medical assistant in cardiovascular testing

Answer 3

Prepping patient for procedure, providing post-procedure assistance, accurately and efficiently performing the testing, noting obvious abnormalities that need immediate intervention, maintaining equipment, preparing testing materials for provider interpretation

Question 4

Instructions for a patient for EKG

Answer 4

Help to ensure a pleasant experience.

1) Identifying the patient using a minimum of two identifiers (NAME, DOB, last four SS, address, phone number). Ask “what is” rather than asking them to confirm

2) Explaining the procedure - harmless, records activity of the electrical system within the heart, no electrical current is sent. Only takes a few minutes, but they should not move or talk once the leads are connected. Any questions?

3) Disrobing instructions - undressed from the waist up, panty hose or tights should be removed. Drape or gown applied with opening in front. Have a light drape or blanket available to place over the patient once the leads are placed. Remove all jewelry and electronic devices - these could lead to artifacts on the EKG tracing

Question 5

Multichannel vs three-channel vs single-channel EKG

Answer 5

Multichannel monitors all 12 leads, can record three, four, or six leads at a time

Three-channel EKG is typically found in the ambulatory care setting, records 3 leads at a time

Single channel records one at a time and produces a running strip

Question 6

EKG dot matrix measurements

Answer 6

Small squares 1mm^2

Vertical axis: gain or amplitude, small square represents .1 MV
- normal amplitude is 10 mm or 1 mv

Horizontal axis: time, small square represents .04 s
- paper is ran at 25 mm/s

Question 7

Preparing skin for electrodes, general guidelines for placement EKG (including leg amputation)

Answer 7

Patients should avoid applying any substance to the skin. Use alcohol wipes or soap/water at attachment sites if necessary. Clip hair if necessary, shave small areas if still necessary. If leg amputated put electrode above hips

Question 8

Leads I,II, III + AVL, AVR, AVF; polarity

Answer 8

Leads 1, II, III are bipolar, Leads AVL, AVR, and AVF are unipolar.

Leads 1, II, and II describe impulses between the arms and legs.
Leads AVL, AVR, and AVF describe impulses from the heart to either the lower, right, or left areas of the front of the body

Describe the electrical communication between the limbs and between the limbs and the heart

Question 9

Electrode placement limbs; color

Answer 9

Limb electrodes should be placed on fleshy areas of skin and within same general vicinity on each limb. With a leg amputation place on lower abdomen, not on bone.

In a circle:
White: right arm
Black: left arm
Red: left leg
Green: right leg

Question 10

Placement of abdomen leads V1-> V6; polarity

Answer 10

V1: Right of sternum, fourth intercostal space
V2: Left of sternum, fourth intercostal space
V3: Between V2 and V4
V4: Left of sternum, fifth intercostal space, midclavicular line
V5: Left of sternum, fifth intercostal space, anterior axillary line
V6: Left of sternum, fifth intercostal space, midaxillary line

All precordial leads are unipolar

Question 11

Location of intervals and segments EKG recording

Answer 11

Question 12

P wave

Answer 12

Represents ATRIAL depolarization, small bump at beginning of graph

Question 13

QRS wave

Answer 13

Represents VENTRICULAR depolarization/contraction (atrial repolarization occurs but is not visible), sharp spike

Question 14

T wave

Answer 14

Represents VENTRICULAR repolarization/relaxation, large bump after QRS wave spike

Question 15

U wave

Answer 15

Not always visible, repolarization of bundle of His and Purkinje fibers, small bump at end of graph

Question 16

P-R interval

Answer 16

Starts at the beginning of P wave, ends at the beginning of the Q wave. Represents the time it takes from the beginning of atrial depolarization to the end of ventricular repolarization

Question 17

QT interval

Answer 17

Starts at the beginning of the Q wave and ends at the end of the T wave. Represents the time from beginning of ventricular depolarization to the end of ventricular repolarization

Question 18

ST segment

Answer 18

Starts at the end of S wave and ends at the beginning of the T wave. Represents the time from end of ventricular depolarization to beginning of ventricular repolarization

Question 19

Proper monitoring of tracing EKG

Answer 19

Medical assistant should monitor to make sure leads were connected properly and that artifacts are not appearing.

Confirm universal standardization mark (indicates standard amplitude), tracking baseline, no abnormal spikes, visible P, QRS, and T waves. Waveforms should be positively deflected unless there is cardiac pathology

Question 20

Precautions EKG

Answer 20

Take any complaints of chest pain seriously and notify provider.
Minimize risk of syncope (fainting) by having patient sit for a short while before standing
Minimize risk of dyspnea (difficulty breathing) by elevating the head to semi-Fowlers if necessary

Question 21

Somatic tremor

Answer 21

Irregular spikes throughout tracing, related to muscle movement. Could be shivering, or Parkinson’s

Question 22

AC interference

Answer 22

AKA 60-cycle interference, related to poor grounding or external electricity interfering with tracing (lights, computers, crossed lead wires)

Question 23

Wandering baseline

Answer 23

Poor electrode connection. Can be associated with lotions, oils, powders

Question 24

Interrupted baseline

Answer 24

Obvious break in the tracing, usually disconnected or broken lead wire

Question 25

Artifacts definition (EKG); prevention

Answer 25

EKG alterations not related to cardiac electrical activity.

To reduce tremor keep patient calm, warm; have lay hands palms down under buttocks.
To reduce AC interference ensure proper grounding of the machine, use three-prong plug, avoid crossed wires, move bed from wall, turn off unnecessary electronic devices.
To avoid wandering baseline clean skin, avoid creams/lotions

Question 26

Sinus bradycardia

Answer 26

Abnormally low heart rate (less than 60/min), not usually significant

Question 27

Sinus tachycardia

Answer 27

Abnormally high heart rate (greater than 100/min), not usually significant

Question 28

Sinus arrest

Answer 28

SA node failed to fire, not significant unless lasts longer than 6 seconds

Question 29

Atrial flutter

Answer 29

Atria are contracting at a rapid rate much faster than the ventricles are contracting

Question 30

Atrial fibrillation

Answer 30

No organized contraction of the atria; quivering state where blood clot formation is possible

Question 31

Ventricular fibrillation

Answer 31

Ventricles are in quivering state, no discernible waves noted

Question 32

Asystole

Answer 32

Heart stops. No noted rhythm

Question 33

P wave negative deflection

Answer 33

Junctional dysrhythmia is likely present, typical impulse pathway from SA to AV node is not occurring. The impulse is occurring in the AV node or some other source

Question 34

Premature ventricular contraction

Answer 34

Wide and bizarre QRS, indicates possible ventricular arrhythmia occurring