Diagnostic Features of the EKG Flashcards Preview

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Flashcards in Diagnostic Features of the EKG Deck (49):
1

Qtc Equation?

Qtc = QT/ sqrt(RR)

2

Cause of the P wave

Atrial Contraction

3

Cause of the PR interval

index of conduction time across the AV node

4

PR Interval Length

0.12 - 0.20 seconds

5

Q-Tc Interval

Less than 0.44 s

6

Light Lines on EKG represent what amount of time?

0.04 Seconds

7

Heavy Lines on EKG represent what amount of time?

0.2 Seconds

8

Heart Rate Equation from EKG

HR = 300 / # heavy lines between 2 QRS's OR HR = 1500 / # mm between 2 QRS's

9

Positive Deflection results from?

Depolarization moving towards a positive electrode

10

QRS will be upwards in which leads?

Left and Lateral Leads

11

QRS will be downwards in which leads?

Right

12

# of Bipolar Leads and Locations?

3 Total. I, II, III. They are located on the right and left arms, and the left foot/leg.

13

Lead II direction of positivity?

Right hand (negative) towards left foot (positive)

14

Lead I direction of positivity?

Right hand (negative) towards left hand (positive)

15

Lead III direction of positivity?

Left hand (negative) towards left foot (positive)

16

Augmented Limb Leads?

aVR (augmented right hand), aVL (left hand), and aVF (left foot)

17

Precordial Leads

V1 - V6.

18

aVR Deflection Direction? Positive, Negative or both?

Directionality from heart towards RAISED right hand produces a completely negative EKG. (p, qrs and t all negative)

19

II, III and AVF are all referred to as...?

Inferior Leads. Give information about the inferior wall of the heart. Damage to this region would best be seen in these leads.

20

I and AVL are referred to as....?

Lateral Leads. Lateral infarcts in the upper/higher portion of the left ventricle would be seen here.

21

Note: Almost all infarcts occur in the left ventricle.

This means you, Soliman.

22

V1 Location

Right Sternal Border. Near SA node. Shows right ventricular Abnormalities and septum.

23

V2 Location

Left Sternal Border. Also looking at right side of the heart. Shows right ventricular Abnormalities and septum.

24

V3 Location

Left Sternal Border below V2. Shows septal defects and a portion of the left ventricular free wall.

25

V4

Below Pec Major in 4th intercostal space. Shows septal defects and a portion of the left ventricular free wall.

26

V6

Placed Lateral to V5 in 4th intercostal space. Left ventricular lead.

27

What is the plane of the precordial leads?

Horizontal Plane. Take a "slice" of the heart.

28

V5

Below Pec Major in 4th intercostal space. Exclusively left ventricular lead.

29

Ventricular Hypertrophy EKG

Increased Volts/Amplitude of QRS complex in certain leads.

30

Left Ventricular Hypertrophy Leads

Big R Waves in left sided leads (I, aVL, V5 and V6)

31

Right Ventricular Hypertrophy Leads

Big R Waves in right sided leads (V1 and V2)

32

Ischemia Definition

Insufficient blood supply to meet demands (in the ventricles)

33

Ischemia EKG Effects

-Depression of the ST segment (Due to inc O2 demand in face of fixed coronary obstruction)
-T Wave Inversion (due to acute coronary artery obstruction during low O2 demand)

34

ST elevation is usually due to...?

Current Transmural Injury (Infarction)

35

Sign of Past Infarction?

Q wave on a completely R positive lead.

36

Significant Q Wave Definition

1) Greater than 1/4 the amplitude of the R wave
2) One small box wide (0.04 seconds)
3) Seen in usually at least 2 leads reflecting the same region of the left ventricle.

37

Transmural Myocardial Infarct Progression on EKG

1) Peaked T-Wave (rare and short)
2) T-Wave Inversion (no damage yet)
3) ST Elevation (injury has occurred)
4) Q-Wave, ST-Elevation, T-Inversion (seen all together- too late!)

38

Subendocardial Infarct causes what on the EKG?

ST Depression... NO Q WAVE!

39

Infarct Location if seen in V1-V2?

Infarct in Anterospetal Wall

40

Infarct Location if seen in V3-V4?

Infarct in Anterior Wall

41

Infarct Location if seen in V5-V6?

Infarct in Anterolateral Wall

42

Infarct Location if seen in II, III, aVF?

Infarct in Inferior Wall

43

Infarct Location if seen in I, aVL?

Infarct in High Lateral Wall

44

Prolonged QT interval Definition

QT Interval is longer than half of the R-R interval

45

Causes of Long QT

Hypocalcemia, hypokalemia, hypomagnesemia
Class 1A or 3 Anti-arrhythmic Drugs
Hypothermia
Congenital Long QT Syndrome

46

Hypokalemia EKG

Flattened T Wave with Presence of merging with U wave. Long QT interval!

47

Hypercalcemia EKG

Shortened QT interval!

48

Hyperkalemia EKG (3 stages)

5.5-7.5 (mmol/L) - Tall T Waves (peaked and symmetrical)
7.5-9.0- P&R waves flatten, QRS&T broaden and big S Waves develop
9.0+ - P&R waves gone, S&T Waves Broaden in a sine wave pattern

49

Hyperkalemia Treatment

Is an acute emergency that can be treated with insulin (among other things).