Module 9 - EKG And Cardiovascular Testing Flashcards
P wave
Represents atrial depolarization, contraction of the atria.
QRS wave
Represents ventricular depolarization, contraction of the ventricles
T wave
Represents ventricular repolarization, relaxation of the ventricles
U wave
Not always visible but represents a repolarization of the bundle of His and Purkinje fibers.
PR interval
- Starts at the beginning of the P wave and ends at the beginning of the Q wave.
- Represents the time from the beginning of atrial depolarization to the beginning of ventricular depolarization.
QT interval
- Starts at the beginning of the Q wave and ends at the end of the T wave.
- Represents the time from the beginning of ventricular depolarization to the end of ventricular repolarization.
ST segment
- Starts at the end of the S wave and ends at the beginning of the T wave.
- Represents the time from the end of ventricular depolarization to the beginning of ventricular repolarization.
Sinus rhythms
Normal rhythms that originate from the firing of the sinoatrial (SA) node and are characterized by the presence of one P wave for each QRS interval on the EKG
Sinus dysrhythmias, also known as arrhythmias, can arise when…
the SA node fires too slowly or too quickly.
Sinus bradycardia is a dysrhythmia characterized by what
a heart rate less than 60/min
Sinus tachycardia is a dysrhythmia by what
a heart rate greater than 100/min and one P wave preceding each QRS complex.
What is a break in the normal EKG
sinus arrest
Abnormal atrial rhythms are characterized by what?
the absence of P waves on the EKG
Commonly encountered atrial rhythms include
atrial flutter, atrial fibrillation, and premature atrial contractions (PACs).
What happens during an atrial flutter?
- a single area within the atrial tissue is firing at a rate faster than the rate the ventricles are responding to.
- results in multiple flutter waves for each QRS complex on the EKG
What happens during atrial fibrillation
- rapid, disorganized firing of multiple sites within the atrial tissue
- results in lots of fibrillatory waves between QRS complexes and an irregular QRS rhythm
What are the risks of atrial fibrillation
developing blood clots and a stroke
When do premature contractions occur
when the atria are triggered to contract earlier than they should, resulting in a premature contraction
Ventricular arrhythmias typically need immediate intervention and include
ventricular tachycardia, ventricular fibrillation, and asystole.
Ventricular tachycardia (V-tach) is a regular, fast rhythm characterized by what
large, irregular, wide QRS complexes on the EKG.
- P waves are absent, not visible, or occur randomly throughout the tracing
What is Ventricular fibrillation
ventricles twitch or quiver, not pumping blood to the rest of the body
What happens to the pulse of a pt if they have a ventricular fibrillation
- no pulse, as the ventricles cannot pump any blood,
- patients typically become unconscious within seconds.
What is asystole
he complete absence of any waves on the EKG tracing
Somatic tremor
characterized by irregular spikes throughout the tracing and is related to muscle movement.
shivering can occur when the patient is cold, causing an irregular tracin. This is an example of what
somatic tremor
Medical conditions such as Parkinson’s disease can result in
somatic tremors
- have them lay their hands palms-down under their buttocks to reduce somatic interference.
How to decrease somatic tremors
by decreasing patient anxiety and providing warmth and comfort as needed.
AC interference, or 60-cycle interference
- characterized by regular spikes in the EKG tracing
- related to poor grounding or external electricity interfering with the tracing
What are some electrical equipments that can cause an AC interference
lights, computers, and other items plugged into wall sockets
How to avoid an AC interference
Ensure proper grounding of the machine by using a three-prong plug, avoiding crossed lead wires, moving the bed away from the wall, and turning off unnecessary electronic devices.
A wandering baseline results from what
movement associated with breathing or poor electrode connection
What will happen to the baseline during a wanering baseline result
The baseline will wander away from the center of the paper, causing difficulty in tracing interpretation
How will a EKG tracing appear In an interrupted baseline
a flat, horizontal line will print on the EKG tracing
How to avoid an artifact
- Turn off all electronic devices, such as cell phones, and remove them from the patient
- Poor-quality or expired electrodes or gel
Electrodes are placed on 10 areas of the body to record heart activity from ___angles and planes
12
Each small horizontal square represents ___ seconds
0.04
What is the usual speed and amplitude of an EKG machine
- s: 25 mm/second.
- amplitude is 10 mm or 1 mv.
What is the time period captured by one large square containing five small boxes on the EKG?
0.20 seconds
Leads I, II, and III are bipolar and record impulses that travel from where
a negative to a positive pole at specific positions in the heart
Lead I records impulses between what
right and left arms
Lead II records impulses between
the right arm and left leg
Lead III records impulses between
the left arm and left leg.
In aVL, the left leg and right arm assist with
the left arm tracing
In aVR, the left arm and left leg assist with
the right arm tracing
In aVF, the right and left arms assist with
with the left leg tracing.
White wire
right arm
black wire
left arm
red wire
left leg
green wire
right leg
V1 wire colour and area of placement
red; right side of the sternum at the fourth intercostal space
v2 wire colour and placement
yellow; left side of the sternum, directly across from V1 at the fourth intercostal space
v3 wire colour and placement
green; left side of the chest, midway between V2 and V4*
v4 wire colour and placement
blue; left side of the chest, fifth intercostal space, midclavicular line
v5 wire colour and placement
orange; left side of the chest, fifth intercostal space, anterior axillary line
v6 wire colour and placement
purple; left side of the chest, fifth intercostal space, midaxillary line
V4 is placed before which wire
V3
A medical assistant is placing electrodes for an EKG on a patient’s left upper arm due to a left below-the-elbow amputation. Where should the MA place the right arm lead?
Right upper arm
After the EKG has been recorded, you must check the printout to ensure what
- Make sure the standardization mark is 10 mm high.
- Check the direction of the R wave in lead I. The R wave on lead I should have a positive deflection. If it has a negative deflection, the limb leads are not attached correctly. Reattach leads and run the EKG again.
- Observe and check for artifacts.
Proper positioning of the electrocardiograph machine reduces which artifacts.
60-cycle interference artifacts.
The calibration box should measure ___mm tall by __ mm wide at the standard setting.
10
5
What is thallium
a dye that provides additional information on blood flow within the heart
Holter monitor
A portable device for cardiac monitoring that is worn for 24 hours-72 hours.
When should Patients press the “event” button on the holter monitor
if they experience any cardiac symptoms (such as palpitations) or neurological symptoms (such as syncope) and record a description of the activity surrounding the symptoms.
