Common ECG Abnormalities Flashcards
what time is 5 small squares
0.2s
what amplitude is 5 small squares
0.5mV
what is normal QTc
350-450ms
whatis Bazzett formula
QT/√RR
what makes sinus rhythm (4)
regular P-P interval
1:1 P:QRS interval
QT<120ms
PR<160ms
what are segments
lines between waves
what are intervals
wave to wave
except PR interval which is start of P to start of Q
dodgy sinus arrhythmia
older people, not cyclic with breath
heart disease
digoxin toxicity
sinus tachycardia causes
drugs
stress
anaemia
HF
fever/pain/sepsis
hyperthyroid
hypovolemia
hypotension
Why might you not see a p wave in sinus tachycarida
yes but can be hidden in next T wave
causes of sinus bradycardia
opiates
digoxin
sinus sick syndrome =SAN damage
lithium/organophosphate poisonoing
AF on ECG
no p waves
irregular rhythm and shape
normal QRS
absent T waves
tachycardia
A flutter
sawtooth f waves
bpm around 100
AVNRT?
AV node reentrant tachycardia
2 Key feature of Wolff Parkinson White syndrome
delta wave. wide QRS
what is WPW syndrome?
bundles of Kent bypass AVN so ventricles depolarise prematurely
what can WFW cause
AF or AVNRT
VT features
> 120bpm
3 wide QRS complexes in a row
VF
> 180
No P, QRS or T
what is the cause of heart block and what is it?
sclerosis or fibrosis
elec signal is delayed or doesn’t get to ventricles
1st degree heart block
bradycardia
1:1 ratio P:QRS interval
Prolonged PR >200ms
Wenkebach
PR interval gradually increases til a QRS is missed
increased vagal tone
but can be beta blockers
hyper K+
calcium blockers
digoxin
Lyme disease
Fingolimod
what is wenkebach also
mobitz type one, 2nd degree heart block
mobitz type 2
some absent qrs complexes
not gradual PR prologation
dangerous
consistent PP interval
RBBB
Marrow
M on V1
W on V6
QRS>120ms
LBBB
William
W on V1
M on V6
QRS >120ms
what leads show what bit
Septal V1, V2
Anterior V3, V4
Inferior, II, III, AVF
Lateral, V5, V6, I, AVL
when ST eleveation or depression
full thickness STEMI - elevation
partial thickness NSTEMI, depression
ST elevation in comparison to what
TP segment
posterior MI which leads depression ST segment
V1, V2
why would T waves be inverted in adult if not MI (2)
subarachnoid haemorrhage (neurological T waves)
PE -> right heart strain
T wave inversion V2-V5
MI
Big U waves?
always pathological
In which leads are Q waves normally absent
V1-V3
morphology of pathological Q waves
deep
>40ms or >25% depth of QRS
Q waves on V1-V3
could be acute MI if also ST elevation etc
or could be previous or developing MI
normal axis range
-30 to 90 degrees
where is 0 degreees on ECG
pointing to the right as you look at it
what is say -60 called
Left axis deviation
what is say +110 called
right axis deviation
where is extreme axis deviation
-90 - -180 degrees
what is baseline
t-p segment
what leads to calculate axis
lead 1 and AVF then lead 2
signs of PE on ecg
SQT
deep S wave in lead 1
deep Q wave in lead 3
inverted T wave in lead 3
Hypokalemia sign no ECG
massive U wave
Hyperkalemia on ECG
Big, sharp pointed T waves
sign of junctional rhythm
inverted P waves on lead 2
bradycardia
P waves can be hidden in QRS or after QRS
