Feature of complete heart block on the ECG – Medicine MCQ

Which of the following is not a feature of complete heart block on the ECG:
a) Constant RR interval
b) Constant PP interval
c) Constant PR interval
d) PP interval shorter than RR interval

Correct answer: c) Constant PR interval

Complete heart block – ECG

In complete heart block the atria and ventricle are totally dissociated. Hence PR interval is totally varying. Constant PR interval would mean sequential atrioventricular activation, which is absent in complete heart block.

Read more on electrocardiographic features of complete heart block at: https://cardiophile.org/electrocardiographic-features-of-complete-heart-block/