ECGs Flashcards
What is the cut off heart rate for a tachycardia?
100bpm
What is the cut off heart rate for a bradycardia?
50bpm
How long is a narrow complex tachycardia?
Less than 120ms
How long is a broad complex tachycardia?
Greater than 120ms
Give examples of a narrow complex tachycardia
AF
Atrial flutter
Sinus tachycardia
Re-entrant tachycardia (AVNRT, AVRT)
Give examples of a broad complex tachycardia
Ventricular fibrillation
Ventricular tachycardia
Torsades de pointes
Give examples of rhythms without a p wave
AF
Atrial flutter
VF
VT
How do you recognise LAD?
Most positive QRS complex in lead aVL
How do you recognise RAD?
Most positive QRS in lead III or aVF
What does a bifid p wave mean?
P mitrale
= left atrial enlargement
Due to prolongation of atrial depolarisation
How long is the PR interval meant to be?
3-5 squares
= 0.12-0.2ms
What causes a long PR interval?
Heart blocks
How is the PR interval measured
Beginning of P to start of Q
Describe first degree heart block
PR interval longer than 5 squares (0.2s)
Describe mobitz I heart block
Gradual lengthening of PR interval, then p wave with no QRS complex
Deprive mobitz II heart block
Long PR interval with dropped QRS complexes
Describe third degree heart block
No relationship between P and QRS
State the system for descibnig ECGs
name, correct recording rate rhythm axis p waves PR interval QRS complex ST segment T waves
How do you calculate the rate on an ECG
300/no of large squares in R-R interval
OR
6 x no of QRS complexes
What can cause right axis deviation
right ventricular hypertrophy
What can cause left axis deviation
LBBB
left anterior hemiblock
Wolff-Parkinson-White syndrome* - right-sided accessory pathway
hyperkalaemia
what can cause a shortened PR interval
if the p wave originates closer to the AVN
accessory pathway
What is R wave progression
S wave > R wave in leads V1-V3
changes to S wave < R wave in lead V4 in healthy heart
What is the ST segment
end of S to start of T
What causes tall T waves
hyperkalaemia
hyperacute STEMI
what causes inverted T waves
ischaemia
bundle branch block
PE
left ventricular hypertrophy
What can cause poor R wave progression
old MI
LBBB
LVH
WPW
