Week 3 - ECGs + Basic Dysrhythmias

Question 1

What heart changes might be seen in someone who is a heavy smoker?

Answer 1

Atrial enlargement - abnormal P-waves

Question 2

What does an inverted T-wave indicate?

Answer 2

ischemia

Question 3

What ECG changes indicate cardiac injury?

Answer 3

ST Elevation
–> NSTEMI may also occur

Question 4

pathological Q waves indicates what?

Answer 4

History of infarction

Question 5

How do pacemakers affect ECGs?

Answer 5

It might be visible before the area that it is correcting - pacer spike

Question 6

What patient will spend more time in the relative refractory period?

Answer 6

A person with a lower HR will see longer Q-T intervals
–> Higher risk of entering a lethal rhythm

Set up 12-lead and look at QTs to determine if it is truly prolonged

Question 7

What is sinus rhythm?

Answer 7

Regular 60-100 bpm

Question 8

What is the inherent rate of the AV junction?

Answer 8

40-60 bpm
–> Junctional rhythms start here

Question 9

What is the inherent rate of the Purkinje fibers?

Answer 9

20-40 bpm

Question 10

One small square on an ECG is how many seconds?

Answer 10

0.04 seconds
–> 5 boxes = 0.2 seconds

5 large boxes = 1 second.

Question 11

The P-wave is related to atrial depolarization. What does a good P-wave look like?

Answer 11

Upright, round, uniform
–> Followed by QRS complex

Question 12

What does a PR interval represent? How long should it be?

Answer 12

Represents the time taken for the impulse to travel from the SA to the AV node.
–> 0.12-0.20 seconds

Question 13

What ECG changes indicate a 1st degree heart block?

Answer 13

A PRI longer than 0.20 seconds

Question 14

What does the QRS complex represent? How long should it be?

Answer 14

Ventricular Depolarization + Atrial repolarization
–> 0.06-0.12 seconds

Question 15

What does the T-wave represent? What does a healthy one look like?

Answer 15

Ventricular Repolarization
–> Upright, round, uniform. Follows QRS complex

Question 16

What does a QT interval represent? Why is a prolonged QT concerning? How long should a QTi be?

Answer 16

Length of time it takes for the ventricle to depolarize and repolarize
–> Increased time in relative refractory period means increases susceptibility for ventricular dysrhythmias
–> 0.36-0.44 seconds

Question 17

What are the steps of interpreting an ECG?

Answer 17

1. Rhythm
2. Rate
3. P-waves
4. Determine PRI duration
5. Determine QRS complex duration
6. Evaluate T wave
7. QT interval
8. Other components (ectopic beats, ST segment)
9. Assess: stable or unstable
10. interventions

Question 18

How long does an ECG need to be in order to be interpreted?

Answer 18

6 seconds - 30 big boxes

Question 19

How can you measure regularity of an ECG?

Answer 19

Map r-wave to r-wave on a paper and determine if they are equal (Ventricles)

Then do the same for p-waves (Atria)

Question 20

How can you measure the HR of a regular HR on ECG?

Answer 20

Multiply the 6 second strip by 10.

Question 21

What is the 1500 method? When is it used?

Answer 21

Used to determine rate of regular ECGs. Most accurate, useful for atrial flutters/tachy
–> Count small boxes between P-waves. Divide 1500 by the distance between p-waves.

Question 22

What does a premature atrial contraction look like?

Answer 22

A p-wave that looks different than others or is not followed by a QRS complex

Question 23

What does a premature junctional beat look like?

Answer 23

Absence or inversion of a p-wave.

Question 24

What is a premature ventricular complex?

Answer 24

Absent p-wave and QRS complex > 0.12 seconds

Question 25

What is considered ST elevation or depression?

Answer 25

1-2 mm outside of normal range that lasts for 1 minute with or without symptoms

Question 26

What are some possible etiologies of sinus bradycardia?

Answer 26

--> Sleeping, well conditioned athletes --> Inferior or posterior MI --> Vagal stimulation --> Carotid sinus pressure --> Increased ICP --> Obstructive sleep apnea --> CCB, digitalis, b-blockers, amiodarone Hypo...xia, thermia, thyroidism, K. HyperK

Question 27

If someone has sinus bradycardia what should you ask?

Answer 27

Wonder if this is normal for the person --> Sudden drops can indicate decompensation Assess for symptoms (Chest pain, SOB, LOC changes, HypoTN)

Question 28

If someone is symptomatic with sinus brady what interventions should be done?

Answer 28

--> O2 --> IV access --> Notify Physician --> Administer atropine --> Consider pacemaker (transcutaneous, transvenous, permanent)

Question 29

What are potential etiologies of sinus tachycardia?

Answer 29

Increased workload --> Fever, exercise, pain, anxiety, hypoxia, HF, acute MI, infection, sympathetic stimulation, hyperthyroidism Medications --> Epi, atropine, dopamine, dobutamine, caffeine, nicotine, cocaine, amphetamines, cannabis Hemodynamics --> Shock, dehydration/hypovolemia

Question 30

What interventions should be taken if someone has sinus tachy and is symptomatic?

Answer 30

--> O2 --> Ensure IV access --> Call physician --> Correct etiology

Question 31

Why is sinus tachy more concerning in someone with CAD/cardiac pathology?

Answer 31

Less time in diastole --> Less coronary perfusion in someone who has underlying perfusion issues.

Question 32

What is the visual difference between a-flutter and a-fib?

Answer 32

Saw tooth pattern vs fibrillatory waves

Question 33

What is considered a controlled ventricular rhythm when there is an uncontrolled atrial rhythm?

Answer 33

Less than 100.

Question 34

What is meant by 4-1 controlled a-flutter?

Answer 34

Atrial flutter where there are four atrial contractions per ventricular contraction. It is regular. If it were not regular it would be considered variable a-flutter

Question 35

What is a superimposed t-wave?

Answer 35

When another wave is hidden within the t-wave - such as a p-wave in a-flutter

Question 36

When do we want to cardiovert someone with new-onset atrial fib/flutter?

Answer 36

Within 48 hours --> Prevent ischemic stroke/PE

Question 37

What is cardioverting?

Answer 37

Applying pressure on the R-wave to convert someone back into a normal atrial rhythm

Question 38

What are the two rhythms that can be defibrillated?

Answer 38

V-tach without pulse V-fib

Question 39

If someone is in pulseless V-tach, what are the interventions?

Answer 39

--> Call the code --> CPR --> Delegate for crash cart, compression board, airway --> defibrillate --> O2 (Bag or intubate) IV EPI, amiodarone or lidocaine, and mag Treat reversible causes (Hs and Ts)

Question 40

What do you do if someone is in stable V-tach/wide complex tachy?

Answer 40

--> Notify physician --> O2 --> IV access - amiodarone/procainamide

Question 41

What are the interventions for asystole?

Answer 41

--> CPR --> Crash cart --> O2 (FiO2 100%) --> Ensure IV Access - Epi, atropine --> Treatment reversible causes

Question 42

What are some possible causes of cardiac arrest?

Answer 42

Hypovolemia, hypoxia, acidosis, K, hypothermia, hypoglycemia Tamponade, toxins, tension pneumothorax, thrombus, trauma

Question 43

What is supraventricular tachycardia?

Answer 43

Tachys originating from above the ventricles - junction, atria

Question 44

What are the phases of repolarization?

Answer 44

0 - Rapid depolarization 1 - Early repolarization 2 - Plateau 3 - Rapid depolarization 4 - Resting potential

Question 45

What do you do if someone is in unstable wide complex tachycardia?

Answer 45

Call MD stat /+ RACE team O2 IV access Cardioverting

Question 46

What might a rapid HR with narrow QRS complexes indicate? What can you do to treat it?

Answer 46

Hypovolemia or... --> Administer blood/fluids Tamponade - also presents with JVD and muffled heart sounds --> Treat with a pericardiocentesis, which will require a thoracotomy

Question 47

What might brady with cyanosis indicate? How is it treated?

Answer 47

Hypoxia --> Airway, ventilate with O2

Question 48

What might a might a low amplitude QRS indicate? How is it treated?

Answer 48

Occurs with acidosis --> Treated with ventilation, sodium bicarb, or dialysis

Question 49

What might flat T waves and a U wave indicate? How is this treated?

Answer 49

HypoK --> Give potassium

Question 50

What might a peaked T wave with wide QRS complexes indicate? How is it treated?

Answer 50

HyperK --> Shift or dialyze

Question 51

How can we treat a PE?

Answer 51

Embolectomy, fibrinolytics, anticoagulation