ECG

Question 1

5 steps of reporting an ECG

Answer 1

rhythm
conduction intervals
axis
QRS description
ST segment and T wave description

Question 2

normal PR inverval

Answer 2

120-200 ms (3 to 5 small squares)

Question 3

normal QRS complex time

Answer 3

120 ms (3 small squares)

Question 4

normal QT interval

Answer 4

controversial but <450 ms (you should use the QTc. the QTc lengthens with bradycardia and shortens with tachycardia. the QTc corrects for this by dividing by the square root of the R interval)

Question 5

where is the QT interval measured from

Answer 5

start of Q to end of T

Question 6

what axis deviation occurs in PE

Answer 6

right (use right hand in PE lessons)

Question 7

left vs right axis deviation ecg findings

Answer 7

left = neg in III initially, then II
right = I neg, III positive

remember to think about where the leads are and you can work it out from that

Question 8

causes of 1st degree heart block

Answer 8

coronary heart dis
digoxin tox
electrolyte distrubances

Question 9

what is 1st deg heart block

Answer 9

wave conducted to ventricles from atria but htere is a delay -> increased PR interval

Question 10

types of 2nd deg heart block

Answer 10

mobitz type 1 = progressive lengthening of PR then failure of ventricle depolarisation. the number 1 is loonnnngg ———-
mobitz type 2 = constant PR interval with occasional failure of ventricular depolarisation

Question 11

what is 3rd deg heart bock

Answer 11

atrial contraction normal but no conduction to ventricles. not always obvious on ECG. No. P >QRS (since atria contract faster). no consistency in PR interval P interval always the same. R interval alays the same. but NO relation between QRS and P waves

Question 12

what is affected in RBBB vs LBBB

Answer 12

RBBB = RSR1 pattern in V1
LBBB =M pattern in V6 (also has T wave inversion in lateral leads - I, VL, V5-V6)

NB this is bc V1 looks at right of heart and V6 looks at left

Question 13

causes of LBBB

Answer 13

new LBBB = MI until proven otherwise
aortic stenosis
IHD

Question 14

causes of RBBB

Answer 14

RVH
IHD
ASD
PE
cardiomyopathy

Question 15

how to know if ectopic is atrial vs ventricular

Answer 15

atrial = abnormal P wave, normal QRS

ventricular - any shape, v weird looking QRS (P wave occurs at predicted time but one may be missed)

Question 16

types of SVT

Answer 16

atrial fibrillation
paroxysmal supraventricular tachycardia (PSVT)
atrial flutter
Wolff–Parkinson–White syndrome

Question 17

QRS in supraventricular vs ventricular tachycardia

Answer 17

supraventricular - QRS normal or narrow

ventricular - QRS wide

Question 18

what is WPW

Answer 18

pt has abnomal anatomical accessory connection between atria and ventricle
no oAV node to delay conduction .,. wave reaches ventricule early
shrot PR

Question 19

WPW ECG findings

Answer 19

short PR
delta wave (slurred upstroke in QRS)

Question 20

2 possible abnormalities of the P wave and what they mean

Answer 20

peaked = R ATRIAL hypertrophy (tricuspid stenosis, pulm HTN)

broad and bifid = L ATRIAL hypertrophy (mitral stenosis)

Question 21

what is the size of a pathological Q wave

Answer 21

> 1mm width, 2mm deep

Question 22

how high is ST elevation

Answer 22

2 small squares in V leads

1 small square in limb leads

Question 23

st elevation in what leads of pericarditis

Answer 23

ALL OF THEM!!

Question 24

ECG changes digoxin

Answer 24

downslopign ST wave + T wave inversion

Question 25

what can cause T wave inversion? in which leads is T wave inversion normal?

Answer 25

``` ischaemia ventricular hypertrophy BBB digoxin (NB normal in VR and V1) ```

Question 26

ECG changes hyperkal

Answer 26

tall tented Ts disappearance of ST possibel wide QRS

Question 27

ECG changes hypokal

Answer 27

``` t WAVE FLATTENING u WAVE (UMP AT END OF t) ```

Question 28

ECG changes hypocal

Answer 28

hypO = PROlonged QT (they rhyme, unlike shortened)

Question 29

ECG changes hypercal

Answer 29

shortened QT

Question 30

ECG findings RV hypertrophy

Answer 30

R wave > S wave V1, V2 S wave > R wave V6 often accompanied by R axis deviation, peaked P wave (R atrial hypertophy)

Question 31

ECG findings L ventricular hypertrophy

Answer 31

tall R in V5, V6 deep S V1, V2 left axis deviation

Question 32

PE ECG changes (7)

Answer 32

``` most common = sinus tachy peaked P (right atrial hypertrophy) S1Q3T3 = large S in I, Q wave (resembling infarct) in III, inverted T wave in 3*) RVH .,. R axis deviation, tall R in V1 RBBB *also inverted in V2, V3 ```

Question 33

anterior infarct ECG changes

Answer 33

V3, V4 (possibly V2-V5)

Question 34

lateral infarct ECG changes

Answer 34

I, VL, v5, v6

Question 35

inferior infarct ECG changes

Answer 35

III, aVF

Question 36

posterior infarct changes

Answer 36

dominant R waves in V1 (R>S)

Question 37

R wave in V1 is always abnormal. what are the causes?

Answer 37

``` RBBB (incl PE!) WPW posterior MI right ventricular hypertrophy (pulm HTN) duchenne's ```

Question 38

artery in anterior, inferior, lateral, posterior MI

Answer 38

``` anterior = LAD (NB this includes a septal infarct) inferior = RCA lateral = LCx posterior = posterior descending artery (branch of the RCA in 80% pts) ```

Question 39

how to describe a VT

Answer 39

type (monomorphic or polymorphic), duration (sustained or non-sustained) and heart rate

Question 40

what is torsades de point

Answer 40

Polymorphic VT - multiple QRS morphologies

Question 41

what ECG change is at risk of developing polymomrphic VT

Answer 41

prolonged QT interval

Question 42

how to distinguish VT and VF

Answer 42

V hard!! can use brugada criteria but too complicated to learn here fusion beats and capture beats occur in VT

Question 43

what are fusion and capture beats

Answer 43

occur in VT fusion beat - P wave begins to conduct through normal pathway. the abnormal ventricular impulse then conducts retrograde across the AV node, colliding with the sinus impulse. The resulting QRS is a fusion of the normal QRS morphology and the ventricular morphology from the VT. A capture beat is similar to a fusion beat, except the QRS morphology looks completely like the normal QRS complex, as the sinus node impulse conducts to the ventricles before the retrograde ventricular activation occurs

Question 44

J point vs J wave

Answer 44

J point = point where QRS ends at ST starts. used to look for ST elevation J wave = wave before J point associated with hypothermia (Osborne wave)

Question 45

how many beats per min would you tbe thinking atrial flutter

Answer 45

100-175

Question 46

what causes a saw tooth baseline

Answer 46

atrial flutter