ecg+arrhythmias

Question 1

which leads are involved in the frontal plane

Answer 1

limb leads and augmented vector leads

Question 2

horizontal plane has which leads

Answer 2

V leads

Question 3

what does the P wave represent

Answer 3

• atrial depolarization
• ATRIAL CONTRACTION occurs during ST segment
• must have pause after P wave to allow atria to contract & eject contents into ventricle (PR interval)

Question 4

PR interval time should be less than

Answer 4

200ms

Question 5

what happens during the PR interval

Answer 5

covers beginning of P wave to just before QRS complex. Atrial depolarization and contraction.

Question 6

what happens during PR segment

Answer 6

atria contract, while signal is sitting at AV node and bundle of his

Question 7

whats the purpose of the AV node?

Answer 7

AV node and bundle of his slows the conduction speed which allows atria to contract and fill ventricles. . After the atria contract, the signal moves to right and left bundle branches and on to ventricles

Question 8

what does the QRS complex represent?

Answer 8

ventricular depolarization

Question 9

what is the conduction combination during the QRS complex

Answer 9

• bundle branches, purkinje fibres and ventricular muscle cells

Question 10

how many fascicles does the left bundle branch have and how many does the right have?

Answer 10

• left anterior and left posterior

- right only has one

Question 11

QRS duration?

Answer 11

<120ms

Question 12

if the signal is blocked, what happens to the QRS?

Answer 12

gets wider

Question 13

which bundle branch looks like rabit ears

Answer 13

right

Question 14

what is the QRS influenced by?

Answer 14

• muscle thickness
• body habitus
• pericardium

Question 15

what does the ST segment represent?

Answer 15

• gap between ventricular depolarization & repolarization.
• ventricles START to contract

Question 16

if patient has myocardial ischemia, what happens to the ST segment?

Answer 16

it will be depressed

Question 17

if the patient has myocardial infarction, what will the ST segment look like?

Answer 17

elevated

Question 18

wat does the T wave represent?

Answer 18

• ventricular depolarization

- mechanically coincides with ventricular systole

Question 19

whats normal sinus rhythm

Answer 19

60-90bpm

50-60 & 90-100 borderline

Question 20

what is the five steps in diagnosing rhythms?

Answer 20

1. HR
2. rhythm (R-R should be same)
3. are P waves identical?
4. is the PR interval long or short?
5. is the QRS wide or narrow?

Question 21

sinus bradycardia

Answer 21

<50-60bpm

Question 22

sinus tachy

Answer 22

> 90-100bpm

Question 23

if PR interval is >200 and the only thing wrong with ECG, what does this indicate?

Answer 23

First degree AV block

Question 24

describe what happens during atrial flutter?

Answer 24

• atrial contraction is semi organized so P waves look similar to normal P waves. There’s an electrical re-entry loop through the atrial tissue that allow it to depolarize repeatedly. 2-4 P waves for every QRS.

Question 25

describe ventricular fib

Answer 25

• HR 300-600
• IRREGULAR
• P WAVE ABSENT

Question 26

describe tachy

Answer 26

very rapid ventricular beats. Re-entry through ventricles only.

Question 27

which degree AV block happens when there is no association between P waves and QRS

Answer 27

3rd degree

Question 28

which degree of AVblock happens when there is a gradual lengthening of the PR interval until there is a dropped QRS

Answer 28

2nd degree