Rhythm recognition

Question 1

P wave indicates

Answer 1

Wave of depolarisation spreads from SA node through the atrial myocardium

Question 2

6 step approach to help the interpretation of ECG

Answer 2

Step 1 - any electrical activity? Step 2 - what is the ventricular rate? Step 3 - if the QRS regular or not? Step 4 - width of QRS complex wide or narrow? Step 5 - is there atrial activity Step 6 - is atrial activity linked to ventricular activity?

Question 3

Normal QRS duration

Answer 3

Upper limit of normal is 0.12 seconds (3 small squares)

Question 4

What is this?

Answer 4

Mobitz type 1 AV block (Wenckebach AV block)

PR interval shows progressive prolongation after each successive p wave until a pwave occurs without a resulting QRS complex

Question 5

What is this?

Answer 5

VT

Question 6

what is this?

Answer 6

3rd degree (complete heart block)

Question 7

what is this?

Answer 7

Mobitz type 2

There is a consistant (often prolonged) PR interval in the conducted beats but some of the p waves are not followed by QRS complex

Question 8

Normal PR interval

Answer 8

The normal PR interval is up to 0.2 s in duration

0.12 -0.2s

(three to five small squares)

If the PR interval is > 200 ms, first degree heart block is said to be present.

PR interval < 120 ms suggests pre-excitation (the presence of an accessory pathway between the atria and ventricles) or AV nodal (junctional) rhythm

Question 9

T wave represents