Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OSCE stations > ECG interpretation > Flashcards

ECG interpretation Flashcards

1
Q

normal dimensions of the calibration trace

A

1 big square wide, 2 tall. 1mV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

normal measurement of squares

A

1 large = 5mm 1 small = 1mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

normal rate of ECG trace

A

25mm/s

1 large square = 0.2sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how do you calculate HR

A

300/number of big squares between R

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

normal PR

A

120-220ms = 3-5 small squares

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

normal QRS

A

less than 120ms = 3 small squares.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

when does contraction occur

A

between the s and the T. the ECG is just the electrical activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

prolonged QT

A

if over 450 sec

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what counts as left and right axis deviation

A

left is between aVL and straight up

right is between aVF and straight up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is progression

A

QRS change between V1 and V6. inflection point = inter ventricular septum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

overview of good ECG reporting/presenting

A
  1. Report the name and age of the patient
  2. Date of the ECG
  3. Note whether or not the patient was experiencing any chest pain when the ECG was performed.
  4. Record the rate of the ECG. This can be done by dividing 300 by the number of large squares between two QRS complexes, if the rhythm is irregular divide 900 by the number of large squares between 4 successive QRS complexes
  5. Rhythm – check there is a P wave in front of every QRS complex. Is the rate regular, irregular or
    irregularly irregular?
  6. Look for prolongation of the PR interval
  7. Look for extra beats or deflections e.g. that may occur with a paced rhythm
  8. Axis – if the S wave is greater than the R wave in lead I, there is right Axis deviation. If the S wave
    is greater than the R wave in lead II there is left axis deviation
  9. Look at the configuration of the QRS complexes
  10. Look at the ST intervals to see if they are raised or depressed.
  11. Look at the T wave to see if it is normal, inverted or peaked
  12. Give a summary and diagnosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

direction of septum depol

A

from left to right

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

define 1st degree heart block

A

P:QRS = 1:1
PR over 220msec

often a normal variant. poss MI. no treatment .

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

define 2nd degree heart block

A

when sometime a P wave is not followed by a QRS. 3 subtypes

1 - mobitz type 1 (wenckebach phenomenon). benign. PR gets progressively longer then drops a beat and resets

2 - mobitz type 2 = constant PR but occasionally a QRS is dropped.

3 - fixed ratio eg 2:1 or 3:1 etc

often causes by an MI. no treatment for mobitz 1 and 2. if fixed ratio results in bradycardia then can have artificial pacing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

define 3rd degree heart block

A

no association between P and QRS. results in an escape rhythm with a ventricular focus.

MI or fibrosis of the bundle of his or both bundle branches.

often caused by MI or fibrosis. needs a pacemaker.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what happens when you see LBBB

A

cannot interpret further

can be caused often by aortic stenosis or MI
no symptoms means no action treatment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

name of the left sided fascicles

A

left anterior and posterior.

LAF damage = LA hemlock with left axis deviation

LPF damage is rare and causes right axis deviation.

RBBB + LAF damage results in RBBB and left axis deviation = bifascicular block.

18
Q

what is sinus rhythm

A

when deploy starts in the SAN.

19
Q

possible supraventricular rhythms

A

sinus, junctional (AVN) and atrial (anywhere).

20
Q

what are escape rhythms

A

those initiated by a ventricular focus. often slow. can get atrial/ junctional escape rhythms too. atrial escape just has a weird looking p wave but normal QRS. junctional escape = no p wave but normal QRS.

ventricular is wide and abnormal QRS , no p wave. often big gap in rhythm before.

21
Q

extrasystole vs escape beat

A

same appearance but an extrasystole comes early and an escape beat comes late.

22
Q

r on t phenomenon

A

a ventricular extrasystole that occurs at the peak of the preceding T wave. can precipitate VF.

23
Q

different effect on p wave cycle of supra ventricular extrasystole and ventricular

A

the supra’s reset the p wave cycle

24
Q

atrial flutter

A

no flat baseline. sawtooth. can have second degree block to cause narrow complex tachycardia.

25
Q

carotid massage does what

A

causes reflex vagal activity which slows SAN activity and reduces AVN conduction.

26
Q

atrial fibrillation

A

no p waves just an irregular baseline. sometimes flutter waves for a few seconds. QRS complexes come at irregular intervals but are a normal shape.

27
Q

peaked pointy p waves

A

RA hypertrophy eg tricuspid stenosis or pulmonary HT.

28
Q

broad and bifid p waves

A

LA hypertrophy

29
Q

right ventricular hypertrophy

A

V1 height of R wave exceeds that of the S wave and a deep S wave in V6. also sometimes right axis deviation, peaked p waves and T wave inversion in V1 to V4.

30
Q

signs of a PE

A

peaked p waves
right axis deviation
tall r waves in V1
RBBB
inverted T waves in V1 (normal) spreading to V2 and 3.
a shift of the inflection point to the left.

31
Q

left ventricular hypertrophy

A

r wave over 25mm in V5/6 and deep s wave in V1/2

inverted t waves in I, aVL, V5 and 6.

ECG not sensitive to small amounts of hypertrophy

32
Q

what are pathological q waves.

A

bigger than 2 mm deep and 1 mm wide. suggests infarcted tissues with full thickness window.

33
Q

st segment elevation, depression and slope

A

should be isoelectric

elevation = acute injury e.g. MI or pericarditis
depression with an upright t wave is usually ischaemia
downward slope = digoxin

34
Q

t wave

A

normal inversion in WR and W1 and sometimes 3 and v2.

in a semi the st segments will resolve in 24-48 hrs but t wave inversion will often be permenent.

leads adjacent to those with inverted t waves sometimes show biphasic t waves.

35
Q

hypokalaemia

A

flattened t wave and u waves lump

36
Q

hyperkalaemia

A

peaked t waves and st segment disappears. QRS can be widened. magnesium can cause similar changes

37
Q

hypocalcaemia

A

long qt

38
Q

hypercalcaemia

A

short qt

39
Q

causes of RBBB

A

normal, ASD/congenital/ PE

40
Q

causes of LBBB

A

ischaemia, AS, HTN, cardiomyopathy.

41
Q

how do you calculate corrected QT

A

start of Q to end of T
QTc drops as HR rises
massive rise in QTc proportional to risk of ventricular arrhythmia inc torsade de pointes.

maximum slope intercept method to define end of t wave.

QTc = QT/ square root RR, where RR = 60/ HR

can get iPhone apps for this.

when QTc is over 440 sec it is pathological .

42
Q

lead positioning

A

chest =
v1 = 4th intercostal, right sternal edge
v2 = 4th intercostal left sternal edge
v3 between 2 and 4
v4 = 5th intercostal , midclavicular line
v5 = same level as 4 but anterior axillary line
v6 = same level as 4 but mid axillary line.

ra = avr
la = avl
ll = avf
rl = neutral

OSCE stations (60 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions