ECG Interpretation Flashcards
Steps of overall Ecg Impression overview
Step1. Overall impression and check regularity
Step2: Identify P waves ,PR intervals, QRS complexes, ST segments, T waves
Step3. Measure P-P and R-R cycles to check for Regularity
Step4. Measure PR and QRS intervals
Step5. Calculate heart rate
What is a normal PR interval time?
0.12-0.20sec
PR Interval = 4 boxes x 0.04sec
PR interval = 0.16sec
Take the number of small boxes and x by 0.04
What is a normal QRS interval time?
0.04-0.12Sec
QRS Interval = 2.5 boxes x 0.04sec
QRS = 0.10 sec
Take the number of small boxes and x by 0.04
Calculate the heart rate if there is 18.5 boxes between the R-R interval
18.5x 0.04 (time perbox)=0.74
60 (sec) / 0.74 = 81bpm
Explain first degree AV block
Prolonged PR interval (greater than 0.20sec
Explain 2nd degree AV block /Mobitz /wenckebach
PR intervals become progressively longer until a beat is completely missed
Explain 2nd degree AV block, Mobitz 2
Routine Pwaves but some have no beat..
Explain third degree (complete) AV block
No relationship between the Pwaves and the QRS intervals, several missed beats may consecutively occur causing “pauses”
How many types of each heart block are there?
1x 1st degree
2 types of 2nd degree
1x 3rd degree
If the R is far from the P
Then it must be a 1st
If PR gets longer then QRS drop
Then it must be a type1 Wenkebach
If PR stays normal and QRS quits
Then it must be a type2 mobitz
If P and QRS beat independently
Then it must be a complete 3rd degree
1.First degree
2.Wenkebach
3.Seconddegree
4.third degree
1.Far away P
2.Longer then drop
3.Drop randomly
4.beat independently
Which Interval provides a good indicator of myocardial ischemia
PR
QT
QRS
ST Segment
ST segment
