ECG Tutorials Flashcards Preview

Hugh's MD2 Gen Med > ECG Tutorials > Flashcards

Flashcards in ECG Tutorials Deck (43):
1

Why do you get Q waves?

Because the "electrical hole" created by the infarcted tissue means the lead will pick up the R waves on the opposite ventricular wave. 

2

How do pacemakers work?

Set a HR cut off below which the pacemaker will kick in and set the rate

3

What is the pathophysiology of MI?

Rupture of artherosclerotic plaque causing local thrombus formation and occlusion. The plaque can be any size

3

How does the QRS appear in SVT?

Narrow

4

What does the QRS represent physiologically?

The onset of conduction of action potential

4

Why do you get ST elevation?

A current traveling from the endo to the epicardium, when the endocardium is infarcted it doesn't transmit a full action potential

5

What happens in atrial flutter?

Impulse travels around the tricuspid annulus and hits the AV node. Impulses are transmitted depending on the AV node refractory period

5

How does R axis deviation appear?

Negative QRS in I

6

In which condition do you get a delta wave?

Wolf-Parkinson's-White syndrome

7

What determines the HR in AF?

The length of the refractory period of the AV node - as random impulses are occasionally sent from the atria when the AV node is not refractory

8

What do you call two ventricular ectopic beats together?

Cuplets

8

Why might you have a wide QRS?

Bundle branch block

Ventricular origin beat (cell to cell conduction)

Pacemaker

Alternate pathway

9

What is sinus arrhythmia?

When rate changes according to inspiration (faster) and expiration (slower)

10

How do ECG changes progress with time in a AMI

First few hours - ST elevation and reciprical depression

T wave inversion after

Q waves can come anytime

11

Three reasons why beats aren't propagated through the His-Purkinje system after traveling through the AV node?

Third degree heart block causing a ventricular origin beat

Right or left bundle branch block

Pace maker (it's place in the RV and signals are conducted to LV cell-to-cell

11

What drugs are used in AF?

Beta blockers

Calcium channel blockers (non-hydropyridines)

Digoxin

Amiodarone

Adenosine

12

How does L axis deviation appear?

Negative in II

13

Is aVR usually positive or negative?

Negative

13

How do you tell a pacemaker from a defib on xray?

The defib lead is much thicker

14

Describe ECG findings for AF?

Irregularly irregular

No P waves

15

What is the criteria for diagnosis of LVH on ECG?

Positive R wave in V6

+

Negative S wave in the V1

= > 7 large squares

17

What is the most common reason for the absence of p-waves?

AF

18

Is aVL usually positive or negative?

Positive

19

What are some complications of the accessory pathway in WPW?

SVT with narrow QRS (normal AV node pathway is used and signal travels back around through the accessory pathway)

 

Wide QRS SVT (signal travels through the accessory pathway then back through the AV node)

 

AF with wide and narrow QRS' (AF sending signals through both AV node and accessory pathway)

21

What controls the rate in AF?

The AV node - varies between people so it can be fast or slow

23

A wide QRS means what?

Slowed conduction through the ventricles therefore not going through the His-Purkinje system

24

What do you use to revert an SVT?

Adenosine

25

What do Q waves respresent?

Old infarcts

26

Describe the journey of the action potential in Left BBB?

Down the right bundle (fast) then across to left via cell to cell (slow)`

28

What is bigeminy?

Normal beat followed by ectopic ventricular beat

30

 Where do you look on an ECG for right bundle branch block?

Positive in V1

31

How do you tell a R from L BBB?

The wide QRS 

"I can be positive about the side of the block"

LBBB: Positive in V6

RBBB: Positive in V1

William - W pattern = left or Marrow

32

What is your first thought with a wide QRS, regular, and tachycardic ECG?

VT

34

Which drugs slow the AV node

Calcium calcium blockers - verapamil and diltiazam

Digoxin

Beta-blockers

Amiodarone

35

How do people with bigeminy often present (vitals)?

Sinus bradycardia

36

Does everyone with sinus disassociation have third degree heart block?

No, can be sinus bradycardia with escape beats

37

What does a prolonged PR interval mean?

1st degree heart block

38

How do you tell an ectopic is ventricular?

The QRS and T wave are abnormal

39

ST elevation in anterior leads, what will you see in the reciprical leads?

Depression

40

What is the most likely cause of a L axis deviation?

A conduction problem

41

How wide is a normal QRS?

150ms

42

Where is the pathology in Mobitz type II heart block?

His-purkinje system

43

Where is the pathology in Mobitz type I heart block?

AV node