Electrocardiogram (ECG)

Question 1

P wave

Answer 1

Atrial depolarization

Question 2

PR interval

Answer 2

Time for atrial depolarization and conduction fro SA node to AV node

Question 3

PR interval time

Answer 3

0.12-0.20 s

Question 4

QRS complex

Answer 4

Ventricular depolarization and atrial repolarization

Question 5

QRS complex time

Answer 5

0.06-0.10

Question 6

QT interval

Answer 6

Time for both ventricular depolarization and repolarization

Question 7

QT interval time

Answer 7

0.20-0.40

Question 8

ST segment

Answer 8

Period when ventricles are depolarized

Question 9

T wave

Answer 9

Ventricular repolarization

Question 10

Normal sinus rhythm

Answer 10

60-100 bpm

Question 11

Sinus bradycardia

Answer 11

<60 bpm

Question 12

Sinus tachycardia

Answer 12

> 100 bpm

Question 13

Sinus arrhythmias

Answer 13

Sinus rhythm, quickening and slowing of SA node impulses, beat-to-beat variation

Question 14

Sinus arrest

Answer 14

Sinus rhythm with intermittent failure of SA node or AV node with occasional complete absence of P wave or QRS complex

Question 15

Premature atrial contractions (PAC)

Answer 15

Ectopic focus initiates impulse before the SA node
P wave is premature
Benign, occurs with caffeine, stress, smoking, alcohol

Question 16

Atrial flutter

Answer 16

Ectopic atrial tachycardia 250-300 bpm
Sawtooth shaped P waves
Occurs with valvular disease (esp mitral)

Question 17

Atrial fibrillation

Answer 17

Atrial depolarize 350-600 bpm
Irregular undulations without discrete P waves
CAD, HTN, valve dx

Question 18

1st degree AV block

Answer 18

PR interval is longer that 0.20 sec but constant

May be due to meds

Question 19

2nd degree AV block: Mobitz I

Answer 19

Progressive prolongation of PR interval until one impulse is not conducted
Benign

Question 20

2nd degree AV block: Mobitz II

Answer 20

Consecutive PR same/normal followed by nonconduction of one or more impulses
↓ CO= more serious
May progress to 3rd degree AV block

Question 21

3rd degree AV block

Answer 21

All impulses at the AV nodes are blocked, no impulses sent to ventricles
Atria and ventricles are paced interdependently
atrial rate > ventricular rate
*medical emergency= steep ↓ of CO

Question 22

Premature ventricular complex (PVC)

Answer 22

Ectopic focus causing premature ventricular depolarization
QRS wide and aberrant
May be asymptomatic/palpitations
Ie anxiety, caffeine, etc

Question 23

Unifocal PVCs

Answer 23

same ectopic focus + same config

Question 24

Multifocal PVCs

Answer 24

arise from different foci + different config

Question 25

Bigemy

Answer 25

Normal sinus impulse is followed by a PVC

Question 26

Trigeminal

Answer 26

PVCs occur after every two sinus impulses

Question 27

Ventricular tachycardia (v-tach)

Answer 27

3 or more consecutive PVCs at a ventricular rate >150 bpm
QRS complexes are wide and aberrant
Those > 30 sec are life threatening 2 º hypotension

Question 28

Ventricular fibrillation (v-fib)

Answer 28

Ventricles do not beat in a coordinated fashion
No CO = unconscious
Lethal and requires immediate defibrillation

Question 29

Ventricular asystole

Answer 29

No rhythm
Straight-line pattern
Immediate CPR and meds needed

Question 30

ST segment depression

Answer 30

Sign of subendocardial ischemia, digitalis toxicity, hypokalemia
Evaluated at J point

Question 31

ST segment elevation

Answer 31

Earliest sign of acute trans mural infarction

Benign sign of early repolarization

Question 32

Q-wave

Answer 32

Characteristic sign of infarction

Question 33

T-wave inversion

Answer 33

Occurs hours/days after MI as a result of a delat in repolarization