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Flashcards in EKG Deck (60)
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1

Which of the fascicles is easier to block?

Left Anterior Fascicle (single strand - left posterior fascicle is widely distributed so harder to block)

2

Initiates ventricular depolarization cycle

Purkinje system

3

Which lead is at the apical point? (5th intercostal, midclavicular line?)

V4

4

Standard Limb Leads

I, II, III

All positive

5

Augmented Limb leads

aVR - view of heart from patient's R shoulder

aVL - view of heart from patient's L shoulder

aVF - view of heart from patient's Feet

6

Leads that face the bottom of the heart

II, III, aVF

7

Most anterior facing leads

V3, V4

8

Lateral facing leads

I, aVL, V5, V6

9

P wave / normal width and height

Atrial Depolarization

Normal width = 0.12s
Normal height = 2.5mm

**should be upright in II, inverted aVR**

10

QRS complex = / normal width and heigh

Ventricular Depolarization

Normal width = <0.12s
Normal height =

11

ST - T wave

Ventricular Repolarization

12

PR segment

Between end of P wave, beginning of QRS

Amount of time it takes for stimulus to travel through AV node, conducting tissue, up to ventricular depolarization

13

PR interval

P wave + PR Segment

Normal = 0.12 - 0.20 s

Represents time from initiation of impulse in SA node to ventricular depolarization

14

Large Q wave

Prior infarct

15

ST Segment

When myocardium is maintaining contraction to push blood out of ventricle (systole)

Should be no more than 1mm away from baseline

16

T wave

Should be same orientation as QRS (pos or neg)

**Tall / peaked T waves in high K+**

17

EKG paper speed rate

25mm/sec

(so each little box = 1/25th of a second / 0.04s)

18

Length of full EKG (time)

12 seconds - each lead measured for 3 seconds

19

Each little box horizontally =

0.04s

(25mm/sec rate, so 1/25th of a second)

20

Each big box horizontally=

5 little boxes

(0.04 * 5) =

0.20 s

21

5 big boxes horizontally=

1 second

(0.20 * 5)

22

Each little box vertically =

1mm

(0.1mV)

23

Each big box vertically =

5 little boxes = 5mm

(0.5mV)

24

Standard calibration box =

10mm high, 0.20 s wide

25

Establishing rate w Box method

1. Locate peak of R wave that lands on dark vertical line

2. Move right to the next line to start count at 300bpm

3. 300, 150, 100, 75, 60, 50, 43, 37

26

Establishing rate w Complex / Time method

12 second strip = # R waves x 5

27

10 Questions for Analyzing Rhythm

1. Fast or slow?
2. Regular or Irregular?

3. P waves there?
4. P waves look the same? (if no, additional pacemaker firing)
5. P waves before each QRS? (if no, SA/AV nodal block)
6. PR interval consistant? (if no = PAC, MAT, WAP)

7. Are P waves and QRS associated?
8. QRS narrow or wide?
9. QRS grouped or not grouped?
10. Any dropped beats?

28

Only 3 indications of an Irregularly Irregular Rhythm

1. Atrial Fibrillation

2. Multifocal atrial tachycardia (3+ P wave morphological differences w diff PR intervals)

3. Wandering atrial pacemaker (3+ P wave morphological differences w diff PR intervals)

29

If not all QRS complexes have a P wave

SA or AV nodal block

30

If PR interval is not constant

Premature atrial contraction, MAT, or WAP