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Flashcards in ECG Deck (52):
1

How long is 300 big squares

1 minute = 60 seconds

2

How long is 1 big square

60/300 or 0.2 seconds

3

How long is 1 little square

0.04 seconds

4

Average P wave length

2.5 small squares or 0.1 seconds

5

Average PR segment length

2.5 small squares or 0.1 seconds

6

Average QRS interval

2.5 small squares or 0.1 seconds
0.04 to 0.1

7

Average QT interval

10-11 small squares or 0.4 seconds

8

Name of first deflection down

q wave

9

Name of first upward deflection

r wave

10

Name if a second deflection upward

R prime

11

Name of first downward deflection following an upward deflection

s wave

12

If entire configuration only consists of a downward deflection, name?

QS wave

13

Anterior leads

V2, V3, V4

14

Left lateral leads

I, aVL,V5,V6

15

Inferior leads

II, III, aVF

16

Right ventricular leads

aVR, V1

17

Normal q wave size

Not greater than 0.1 mV

18

Normal R wave progression

Usually V1 has the smallest R wave, V5 has the largest and V6 a little smaller than V5.

19

What is the typical relationship between R and T wave orientation?

It is typical for R and T waves in the same lead to have the same orientation.

20

Normal size of T wave

Normal for T waves to be 1/3 to 2/3 of the corresponding R wave.

21

What does the QT interval correlate to?

The time of the beginning of ventricular depolarization to the end of ventricular repolarization.

22

What % of R-R cycle is the QT interval

QT interval is normally about 40% of normal cardiac cycle.

23

Normal axis orientation

Between 0 and 90 degrees, if QRS is predominately positive in leads I and aVF.

24

Which lead is considered 0 degrees

Lead I

25

Which leads are helpful in evaluating the atria, and why?

II and V1.
Lead II: orientated nearly parallel with atrial vector
Lead V1: orientated perpendicular to atrial vector

26

What designates right atrial enlargement

Largest P wave not in Lead II,
Larger in aVF or Lead III

27

What would classify for atrial enlargement with regards to voltage?

P waves with amplitude greater than 0.25mV or 2.5mm in inferior leads (II, III, aVF).

28

What would cause right atrial enlargement?

Severe lung disease

29

Which part of the P wave correlates to the left and right atrium?

The first part of the p wave correlates to the right atrium
The second part to the left atrium

30

What can indicate left atrial enlargement on egk?
There are 2 required elements...

Indication: Second part of the p wave may increase in amplitude.
Requirements:
Terminal part of p wave drop more than 1 mm below the isoelectric line in lead V1.
Terminal aspect of p wave be at least 1 small block (0.04 sec) in width.

31

What is the common cause of left atrial enlargement, and therefore what is the nickname of the finding on ECG?

Mitral valve disease is a common cause of left atrial enlargement.
Nickname: P mitrale

32

What indicates right atrial enlargement on ECG?

increase in amplitude of the first aspect of the p wave

33

What is the nickname of a classic picture of right atrial enlargement on ECG?

P pulmonale = severe lung disease

34

Most common feature associated with right ventricular hypertrophy?

Right axis deviation
QRS between 90-180 degrees

35

Features of RVH other than axis

Dominant R wave in V1
Dominant S wave in V5, V6

36

Most common cause of RVH?

Pulmonary disease and congenial heart disease

37

Calculation for LVH using precordial leads

R wave amplitude in lead V5 or V6 plus S wave in lead V1 or V2 exceeds 35mm
- R wave amplitude in lead V5 exceeds 26mm
- R wave amplitude in lead V6 exceeds 20 mm
- R wave amplitude in lead V6 exceeds the R wave amplitude in V5
Best used in people under 35yo.

38

Repolarization abnormalities

Most common in ventricular hypertrophy
Flipped T waves
RVH: leads V1, V2
LVH: leads I, aVL, V5, V6

39

Classic ECG features for HCOM

ventricular hypertrophy
repolarization abnormalities in leads with tallest r waves
q waves, of uncertain etiology, in inferior and lateral leads

40

What are the most common symptoms of an arrhythmia?

Palpitations and awareness of ones own heartbeat, intermittent accelerations or decelerations.

41

Severe symptoms of arrhythmias?

light-headedness and syncope, angina

42

Causes of arrhythmias

HISDEBS
Hypoxia
Ischemia and Irritability
Sympathetic stimulation
Drugs
Electrolyte disturbances
Bradycardia
Stretch: Enlargement and hypertrophy

43

Non SA node rates of fire

Atrial pacemakers: 60-75
Junctional pacemakers: 40-60
Ventricular pacemakers: 30-45

44

Difference between AVRT and AVNRT

AVRT: re-entrant uses the bundle of kent
AVNRT: functional re-entrant with the AV node

45

Features of AVNRT

- Regular tachycardia: 140-280bpm
- QRS usually narrow
- P waves if exhibited: retrograde in II, III, aVF

46

Common cause of atrial flutter?

Generated by a re-entrant circuit that runs largely around the annulus of the tricuspid valve.

47

Typical rate of p waves in atrial flutter?

250-350 beats per minute

48

Def of ventricular tachycardia
Rate of

A run of three or more consecutive PVCs,
Rate usually between 120-200 bpm

49

Def of ventricular fibrillation

Preterminal event, seen almost solely in dying hearts
No true QRS complexes, heart generates no cardiac output

50

Accelerated idioventricular rhythm
Rate?
When seen?

Ventricular escape focus that has accelerated enough to sufficiently drive the heart.
Rate: 50-100bpm

Benign rhythm that is sometimes seen during an acute infarction or early hours after reperfusion

No P waves, QRS are wide, does not progress to ventricular fib.

51

Torsade de Pointes

Twisting of the points: unique form of v.tac, usually seen in patients with prolonged QT.

52

Average PR interval

0.12 to 0.2; 3 to 4 small boxes