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Flashcards in ECGs Deck (45):
1

What leads show Inferior surface of Ventricles ?

2,3 and aVF

2

What leads show RV and Septum?

V1 and V2

3

What leads show AS of Ventricles?

V3 and V4

4

What shows IV septum and AS of Ventricles ?

V1 to V4

5

What shows lateral surface of ventricles ?

1, aVF , V5 and V6

6

What shows upward deflection?

Depolarisation to the positive end or repolarisation away

7

What shows Downward deflection ?

Depolarisation to the negative end or repolarisation toward

8

Which parts of the Conduction system show flatline?

SAN and AVN depolarisation, Bundle of his and fibrous ring and ST segement.

9

What does P wave show?

Atrial Depolarisation

10

What does QRS complex Show?

Ventricular Depolarisation

11

What does T wave show?

Ventricular Repolarisation

12

What special feature does AVN do?

Delays conduction to allow Atrium to empty

13

How long is PR interval and where ?

3-5 small boxes, Start of P to start of QRS.

14

What is slower and fast sinus rhythm?

Sinus Tachycardia and Sinus Bradycardia

15

What is Atrioventricular conduction blocks?

Delay/ Failure of impulse conduction from atrium to ventricle via AVN and BOH.

16

What is 1st degree Heart Block?

Increased PR interval , more than 5

17

What is Mobitz 1 degree or Wenckenbach Heart block?

PR interval successively longer until QRS dropped

18

What is Mobitz 2 Heart Block?

No PR interval longer and sudden QRS drop.
High risk of complete HB

19

What is 3rd Degree Heart block?

Failure of AV conduction
Atrium and ventricles are independently depolarising
Ventricular Escape rhythm is slow

20

Why is 3rd Degree dangerous ?

Too slow to maintain BP

21

What is shown is bundle brach block?

Wide QRS due to longer ventricular depolarisation

22

What is affected in supraventriuclar?

AV and SA node
Atrium

23

What is affected in Ventricular ?

Ventricular

24

What is main characteristic if irregular ventricular rhythms?

Wide QRS complexes

25

What can cause atrial fib?

Thyrotoxicosis and dilation

26

What is main features of Atrial Fib?

Wavy baseline
irregular R-R interval
Random rapid impulses

27

What is ventricular Ectopic beat?

Ectopic foci in ventricl muscle - random
No impulse in his purkinje system
Wide QRS

28

What is the definition of VT?

Run of 3 or more Ectopic beats and can lead to VF

29

What is VF?

Chaotic fast ventricular depolarisation.
No CO - leads to cardiac arrest

30

What is seen in Supraventricular Tachycardia?

No P waves

31

What part of heart is injured in partial occlusion?

Sub Endocardium

32

Which part of the heart is injured in full occlusion ?

Epicardium - Visceral layer

33

What is seen in full occlusion?

STEMI

34

What are the ECGs seen at Acute, hours , 1-2 days, Days later and finally weeks?

Acute: ST Elevation , R decreases
Hours: Q wave begins
1-2 days: T wave inversion , Q Wave deeper
Days later: ST Normalises , T inverted
Weeks: Q wave persists

35

Why does Q wave show muscle necrosis in the leads it is facing ?

Dead muscle cannot conduct
Electrode looks at other impulses

36

Describe a pathological Q wave ?

> 1 small box wide
>2 small deep

37

What is seen in an old MI?

Normal ST but pathological Q waves

38

What diagnosises can be made by ST depression and T wave insertion ?

Stable angina - when under exercise
Ischemia
Non Stemi MI

39

How can you differentiate between ischemia and Non STEMI MI ?

Blood test for troponin C

40

What causes the less excitability in heart ?

Hyperkalemia - RMP less negative
Inactivation of Na+ channels

41

What are the changes in the ECG for Hyperkalemia?

1. tall T waves
2. Flatten P wave , Widen PR
3. Widen QRS and no P wave
4. QRS and T wave merge

42

What are the changes in ECG for hypokalemia?

1. Flatten T wave
2. Taller U wave
3. ST depression

43

What are the 5 coronary arteries for the AS ?

RCA, LCA, LMA, RMA and LAD

44

What is the coronary artery for the posterior right side?

Posterior intraventricular artery - Plv

45

What is the artery for the posterior left side?

Circumflex -Cx