ECG quiz Flashcards
(43 cards)
How do you determine the rate of an ECG?
300/no. of large squares
Number of complexes on the rhythm strip x 6
What is the definition of a sinus rhythm?
Every P wave followed by a QRS
What are the changes in 1st degree AV block?
PR interval >0.20 sec (>1 large square)
Every P wave followed by a QRS
*age related degeneration of AV node/HIS bundle
What are the characteristics of mobitz type 1 AV block?
PR interval gets longer until a non-doncuted P wave occurs
*can be normal or drug toxicity, MI
What are the characteristics of mobitz type II AV block?
PR intervals are constant until a non-conducted P wave occurs. Must be 2 consecutive PR intervals
Not every P wave is followed by a QRS
*degeneration of AV node
in which type of AV block does the PR interval get longer until the P wave is no longer conducted?
2nd degree heart block -Moritz type 1 AV block
In which type of AV block does the PR interval remain constant until the P wave is no longer conducted?
2nd degree heart block Moritz type 2 AV block
Which carries a worse diagnosis - 2nd degree MObitz type I or type II AV block?
Type II AV block
What is the cardinal feature of complete (3rd degree) AV block?
P waves & QRS complexes but no association between the 2
Which bundle branch block is associated with MarroW (V1,V6)
RBBB:
1) broad QRS complexes >0.12
2) 2nd +ve deflection in QRS complex
3) shutting of the S wave laterally (V5,V6, I & aVL)
4) T wave inversion in septal leads (V1,V6)
Which bundle branch block is associated with WilliaM (V1,V6)
LBBB
1) broad QRS
2) W - V1, M - V6
3) No R waves in leads V1-V4
5) St elevation in anterior leads (V3,V4)
What are the features of atrial flutter?
SAW-TOOH baseline . May be regular or irregular. Ventricular rate can be slow, normal or fast
What are the features of Atrial fibrillation?
1) irregularly irregular QRS
2) chaotic baseline - no clear P waves
3) QS complex looks normal or same as when pt in sinus
If an ECG shows no Pwaves with an irregularly irregular broad complex tachycardia what is the diagnosis?
A. fib with LBBB
QRS morphology typical LBBB pattern
What is the diagnosis in a regular, narrow complex tachycardia?
Supreventrivcular tachycardia
QRS >100bpm
No clear P waves
What is the diagnosis if:
1) short PR interval
2) Delta wave, slurred onset QRS complexes
3) broad QRS
WPW
What is the diagnosis in a broad complex tachycardia with a regular rhythm?
Ventricular tachyarythmie
1) QRS>100bom
2) broad QRS
3) slurred onset R waves
4) signs of AV dissociation
5) QRS morphology constant
What is the difference between VT and V.fib on ECG?
VT = regular V.Fib = choatic in all leads. As VF continues QRS complexes get smaller until eventually ECG has appearance of systole
what is the axis if I,II, avF are positive?
NORMAL
What is a normal axis?
Positive I,II, avF
What are the features of RAD?
Leads I and II are pointing towards each other
QRS is positive (dominant R wave) in leads III and aVF
QRS is negative (dominant S wave) in leads I and aVL
What are the features of LAD?
Leads I and II are pointing away from each other
QRS is positive (dominant R wave) in leads I and aVL
QRS is negative (dominant S wave) in leads II and aVF
In MI which way does the axis change?
LAD or RAD - electrical input away from the ischaemic part of the heart
In PE what is the axis?
Right axis deviation - leads I & II pointing towards each other
