EKG III and IV (Exam 3)

Question 1

Which kind of sinus dysrhythmia is this:

Rhythm: regular

Rate: <60 bpm

P wave: one for every QRS, nl in size/shape/direction

QRS complex: normal (<0.12sec)

Answer 1

Sinus bradycardia

Question 2

Junctional rhythms originate in the

a. SA node
b. AV node
c. Bundle of Kent
d. Bundle of His

Answer 2

AV node! If you chose bundle of kent you owe me a crisp $20 bill.

Question 3

You are looking at an EKG from left to right and it’s going normal, normal, normal, normal, wide QRS followed by a T wave in opposite direction of QRS, normal, normal, normal…

what the heck was that one weird thing in the middle?

Answer 3

Premature ventricular contraction (PVC). They can be unifocal or appear in groupings (bigeminy: every other complex, or trigeminy: every third complex)

Sorry, it’s hard to explain without seeing a picture! Hopefully not too confusing…. see slides 55-58

Question 4

“Saw-tooth” pattern should make you think of……

Answer 4

Atrial flutter!

• Single irritable atrial foci initiates beat rapidly (rate around 300bpm)
• Results in “flutter waves” preceding QRS complex, hence the saw-tooth pattern

Question 5

Define sinoatrial/sinus arrest

Answer 5

SA node fails to initiate a beat

• Rhythm: irregular
• Rate: changing
• P waves: one for every QRS, however a pause (>2 sec) occurs and a new rhythm is then started
• PR interval: nl (0.12-0.20 sec)
• QRS complex: nl (<0.12 sec)

*Often concerning

Question 6

What is the normal duration of the QRS complex?

Answer 6

0.12 sec or less

Question 7

Define sinus arrhythmia

Answer 7

SA node initiates beat but at varying intervals:

• Rhythm: irregular (R to R varies and P to P varies)
• Rate: varies
• P waves: one for every QRS, nl in size/shape/direction
• PR interval: nl (0.12-0.20 sec)
• QRS complex: nl (<0.12 sec)

Question 8

What’s going on with multifocal atrial tachycardia and how do you identify it on an EKG?

Answer 8

• Multiple foci within the atria are firing at a rate >100
  
  • Basically same thing as wandering atrial pacemaker but fast
• Irregularly irregular
• P waves vary
• P-R interval varies
• R-R interval varies
• P:QRS is 1:1

Question 9

What’s this rhythm?

Answer 9

Sinus arrythmia

Question 10

What is going on with wandering atrial pacemaker and how do you identify it on an EKG?

Answer 10

• Pacemaker changes “spots” within the atria
• Rhythm is irregular
• Shape of P waves vary
• P-R interval varies
• P:QRS is 1:1
• At least 3 different P-waves within 1 lead are needed to make dx

Question 11

Name that rhythm: Tachycardic, wide QRS complexes of varying amplitudes, “twisted ribbon”

Answer 11

Torsades de pointes

Question 12

What is this rhythm?

Answer 12

Atrial Flutter

Question 13

Supraventricular tachycardia (SVT) will show up on an EKG with regular atrial and ventricular rhythm, narrow QRS, and a HR between _____ and _____ bpm.

Answer 13

Supraventricular tachycardia (SVT) will show up on an EKG with regular atrial and ventricular rhythm, narrow QRS, and a HR between 160-250 bpm.

Question 14

What’s this rhythm?

Answer 14

Sinus arrest

Question 15

What’s this rhythm?

Answer 15

Idioventricular rhythm

Question 16

What’s this rhythm?

Answer 16

Junctional tachycardia, rate >100

Question 17

What’s going on with premature atrial contractions (PACs)? How do you identify them on an EKG?

Answer 17

• Irritable site within the atria discharges before SA node
• Identified by:
  
  • Early/premature P wave
  • Abnormal P wave differs in shape from a sinus P wave
  • QRS complex is nl
• Not an entire rhythm - just a single beat!

Question 18

Atrial dysrhythmias are caused by abnormal electrical impulse formation and conduction in the atria secondary to decreased function of the ____________, or an ______________ becomes excited.

Answer 18

Atrial dysrhythmias are caused by abnormal electrical impulse formation and conduction in the atria secondary to decreased function of the SA node, or an ectopic atrial foci becomes excited.

*NOT conducted from the AV node!

Question 19

What is the normal duration of a PR interval?

Answer 19

0.12-0.20 sec

Question 20

If every other beat is a PAC, it’s called ___________. If every 3rd beat is a PAC, it’s called _________.

Answer 20

If every other beat is a PAC, it’s called bigeminy. If every 2rd beat is a PAC, it’s called trigeminy (shown).

Question 21

What’s this rhythm?

Answer 21

Wandering atrial pacemaker

Question 22

What’s this rhythm?

Answer 22

Junctional rhythm, rate ~60

Question 23

What’s this rhythm?

Answer 23

SVT

Question 24

Which kind of sinus dysrhythmia is this:

Rhythm: regular

Rate: >100 bpm

P wave: one for every QRS, nl in size/shape/direction

QRS complex: normal (<0.12sec)

Answer 24

Sinus tachycardia

Question 25

Describe ventricular tachycardia

Answer 25

* Ventricular rhythm with rate \>100 bpm * Wide QRS and no other discernible waves * May convert into v-fib or asystole

Question 26

What's this rhythm?

Answer 26

V-tach

Question 27

What's this rhythm?

Answer 27

Atrial bigeminy

Question 28

What's this rhythm?

Answer 28

NSR w/ PVC

Question 29

T/F: atrial dysrhytmias are conducted from the AV node

Answer 29

False! Abnormal electrical impulse formation and conduction in the atria - ectopic foci

Question 30

What's going on here?

Answer 30

Premature atrial contration (PAC)

Question 31

What is the name of this rhythm: * Single foci in the ventricle acting as pacemaker with a rate of 20-40 bpm * P waves usually absent (buried) * QRS wide (\>0.12 sec) * All QRS complexes look the same

Answer 31

Idioventricular rhythm

Question 32

Atrial flutter is almost always (_regular/irregular_) rhythm, whereas a-fib is always (_regular/irregular_)

Answer 32

Atrial flutter is almost always **_regular_** rhythm, whereas a-fib is always **_irregular_**

Question 33

What is this rhythm? What's the rate?

Answer 33

Sinus tachycardia, Rate ~130 bpm

Question 34

What's this rhythm?

Answer 34

Multifocal atrial tachycardia

Question 35

What's the difference between atrial flutter and a-fib?

Answer 35

* **_Atrial flutter:_** single irritable atrial foci initiates beat rapidly * Shows up as saw-tooth p-waves * **_A-fib:_** 300-600 atrial foci firing at once * Absence of discernible P waves * Pictured:

Question 36

\_\_\_\_\_\_\_\_\_ is the most common of all sustained atrial arrhythmias

Answer 36

A-fib! It's present in 3-4% of the population \>70 yrs old

Question 37

What's this rhythm?

Answer 37

A-fib

Question 38

V-fib ain't so bad, right?

Answer 38

\*face palm\* * Chaotic rhythm originating in the ventricles * Quivering heart = no contraction, no pulse, no cardiac output * EKG with chaotic deflections, no nl waveform present * Causes immediate syncope & death within minutes * Presenting rhythm in 70% of cardiac arrests

Question 39

An inverted, late, or missing p-wave is indicative of a _______ rhythm.

Answer 39

An inverted, late, or missing p-wave is indicative of a **_junctional_** rhythm. * Rate is usually slow: 40-60 bpm * But can be accelerated: 60-100 bpm * Can also be tachycardic: \>100 bpm * P-wave sometimes inverted because of the retrograde impulse coming up from the AV node

Question 40

What's this rhythm?

Answer 40

V-fib

Question 41

What is a premature junctional contraction?

Answer 41

* An early beat generated from the AV node. * Just an event, not a rhythm! * Shows up as a single inverted P-wave