EKG

Question 1

SA Node ↓—AV Node↓—Bundle of His ↓ —Purkinje Fibers

Answer 1

The Electrical Conduction System of the Heart

Question 2

ability of pacemaker cells to spontaneously initiate an electrical impulse

Answer 2

Automaticity

Question 3

ability of myocardial cells to respond to stimuli generated by pacemaker cells

Answer 3

Excitability

Question 4

ability to transmit an impulse from cell to cell

Answer 4

Conductivity

Question 5

inability of cardiac cells to respond to additional stimuli immediately following depolarization.- keeps you from going into Vfib

Answer 5

Refractory

Question 6

ability of myocardial fibers to shorten in response to a stimulus

Answer 6

Contractility

Question 7

Fastest rate of automaticity.
Primary pacemaker of the heart
Rate: 60 to 100 bmp

Answer 7

SA node

Question 8

Has a delay which allows for atrial contraction and more filling of the ventricles
Rate: 40 to 60 bmp

Answer 8

AV node

Question 9

Has the ability to self-initiate electrical activity

Rate: 40 to 60 bmp

Answer 9

Bundle of His

Question 10

Network of fibers that carry electrical impulses directly to ventricular muscle cells
Rate: 20 to 40 bmp

Answer 10

Purkinje Fibers

Question 11

Shows: Heart rate, rhythm/regularity, impulse conduction time intervals, abnormal conduction pathways

Answer 11

Information Obtainable From EKG Rhythm Strip Analysis

Question 12

Does not show: pumping action, cardiac output, blood pressure, cardiac muscle hypertrophy

Answer 12

Information NOT Obtainable From EKG Rhythm Strip Analysis

Question 13

Defines the graphic representation of the electrical activity of the heart

Answer 13

Electrocardiogram

Question 14

SA node fires, sends the electrical impulse outward to stimulate both atria and manifests as a P-wave.
Approximately 0.10 seconds in length

Answer 14

P wave

Question 15

Time which impulse travels from the SA node to the atria and downward to the ventricles

Answer 15

PR Interval (PRI)

Question 16

Impulse from the Bundle of HIS throughout the ventricular muscles
Measures less than 0.12 seconds or less than 3 small squares on the EKG paper

Answer 16

QRS complex

Question 17

Ventricular repolarization, meaning no associated activity of the ventricular muscle
Resting phase of the cardiac cycle

Answer 17

T wave

Question 18

Ventricular repolarization

Preparing for the next heartbeat

Answer 18

ST segment

Question 19

Step 1:  Heart Rate
Step 2:  Regular/Irregular
Step 3:  P waves
Step 4:  PR interval
Step 5:  QRS complex

Answer 19

Interpretation of an EKG Strip

Question 20

6-second method: have a six second strip, count the number of QRS complexes and multiply by 10

Answer 20

Heart Rate

Question 21

Heart rhythms are classified as regular or irregular
Determining the heart rhythm involves establishing a pattern of QRS complex occurrences.
Measure ventricular rhythm by measuring the interval between R-to-R waves and atrial rhythm by measuring the P-to-P waves.
Intervals > than 0.06 seconds, irregular

Answer 21

Heart Rhythm

Question 22

Are P-waves present?
Are P-waves occurring regularly?
Is there a P-wave for each QRS complex?
Are the P-waves smooth, rounded, and upright in appearance, or are they inverted?
Do all P-waves look similar?

Answer 22

5 questions to ask about P waves

Question 23

Normal length of the PRI is 0.12 to 0.20 second (3-5 small squares)

Are PRI greater than 0.20 second?
Are PRI less than 0.12 second?
Are the PRI constant across the EKG strip?

Answer 23

PRI and 3 questions to ask

Question 24

Are QRS intervals greater than 0.12 second (wide)? If so, the complex may be ventricular in origin.
Are QRS intervals less than 0.12 second (narrow)? If so, the complex is most likely supraventricular in origin.
Are QRS complexes similar in appearance across the EKG strip?

Answer 24

3 questions to ask about QRS

Question 25

Patient movement Loose or defective electrodes Improper grounding Faulty EKG apparatus

Answer 25

4 common causes of artifact

Question 26

rate of < 60 bmp

Answer 26

bradycardia

Question 27

rate of 60 to 100 bpm

Answer 27

normal rate

Question 28

rate of > 100 – 150 bpm

Answer 28

tachycardia

Question 29

SA node

Answer 29

sinus

Question 30

SA node fails, impulse comes from the atria (internodal or the AV node)

Answer 30

atrial

Question 31

SA node or AV junction fails; ventricles will shoulder responsibility of pacing the heart

Answer 31

ventricular

Question 32

Normal Sinus Rhythm (NSR) Sinus Arrythmia- speeds up during inspiration- due to lungs expanding and pushing on heart- heart gets a little sensitive- this is normal Sinus Bradycardia (SB) Sinus Tachycardia (ST)

Answer 32

sinus rhythms

Question 33

SA node fails to generate an impulse, the atrial tissue or areas in the internodal pathways may initiate impulse. These are called atrial dysrhythmias Generally not considered life-threatening or lethal. Careful and deliberate patient assessment must be continuous.

Answer 33

atrial rhythms

Question 34

o What is the rate: atrial 250-300 BPM ventricular- variable o What is the rhythm: atrial regular, ventricular- regular or irregular o Is there a p wave before each QRS? Are the P waves upright and uniform? Normal P waves are absent replaced by F waves- sawtooth o What is the length of the PR interval? Not measurable o Do all the QRS complexes look alike? Yes o The length of the QRS complexes? Usually less than 0.12 se- 3 small squares

Answer 34

Atrial Flutter

Question 35

o What is the rate: atrial 350-400 BPM ventricular- variable o What is the rhythm? Irregularly irregular o Is there a P wave before each QRS? Are there P waves upright and uniform? Normal P waves are absent, replaced by f waves o What is the length of the PR interval? Not discernable o Do all the QRS complexes look alike? Yes o The length of the QRS complexes is? Usually less than 0.12 sec

Answer 35

Atrial Fibrillation

Question 36

o What is the rate: atrial- 150-250 BPM Ventricular 150-250 BPM o What is the rhythm: regular o Is there a p wave before each QRS? Are the P waves upright and uniform? Usually not discernable especially at the high rate range o What is the length of the PR interval? Usually not discernable o Do all the QRS complexes look alike? Yes o The length of the QRS complexes is? Usually less than 0.12 sec

Answer 36

Supraventricular tachycardia

Question 37

once given rapidly, then 20ml of NS, will see 6 sec of asystole – resets pacemaker of heart- if 6 mg doesn’t work go up to 12 mg- have everything ready first

Answer 37

adenosine

Question 38

most common, can be due to electrolyte issues, hypokalemia, nicotine, tea, coffee, anything that interferes with blood supply to the heart- less cardiac filling so less cardiac output- no P wave

Answer 38

Premature Ventricular Complexes

Question 39

100-250; no atrial rhythm, very regular rhythm , can still have a pulse; Amiodarone, antiarythmic- class 3, bolus then start a drip , there are pills after drip is weaned off- tx- medication, if unstable cardiovert with pulse, if pulseless- defibrillate

Answer 39

Ventricular Tachycardia

Question 40

French term that signifies the “twisting of the points.” May wax and wane in amplitude and may “flip” or “twist” on its electrical axes. Similar to ventricular tachycardia. Caused by hypomagnesemia or by antiarrhythmic drugs. common in Alcoholics – bc low mag, cocaine, certain meds that deplete mag

Answer 40

Torsades de Pointes

Question 41

The absence of a palpable pulse and myocardial muscle activity with the presence of an organized electrical activity (excluding VT and VF) on cardiac monitor. It is not an actual rhythm. It represents a clinical condition wherein the patient is clinically dead, despite the fact that some type of organized rhythm appears on the monitor.

Answer 41

Pulseless Electrical Activity (PEA)

Question 42

hypovolemia, hypoxia, hydrogen ion, hyper/hypokalemia, hypothermia, hypoglycemia

Answer 42

6 Hs

Question 43

tamponade, tension pnuemophorax, thrombosis, trauma, toxins

Answer 43

5 Ts

Question 44

PR interval is greater that 0.20- everything is regular rhythm, rate etc just longer PR interval – caused by cardiac medications

Answer 44

First Degree AV Block

Question 45

– lengthening PR interval until QRS is dropped- then resets to short and then lengthens all over again- ventricular rhythm irregular –tolerated unless heart rate is really slow

Answer 45

Second Degree AV Block (Mobitz Type I) or Wenckebach

Question 46

intermittent failure of the AV node to conduct an impulse to the ventricles without delay-no QRS- a pt may get dizzy depending on how fast rate is – anterior wall MI, if symptomatic- will pace them- on or in them – poor prognosis if remain symptomatic

Answer 46

Second Degree AV Block (Mobitz Type II)

Question 47

atria and ventricles don’t associate- fire whenever, no correlation – totally variable- dig toxic can cause- if tolerated they are watched

Answer 47

Third Degree AV Block (Complete)

Question 48

sensing or pacing

Answer 48

artificial pacemaker