Question

In ecg, p-r interval corresponds to



(a) time delay in a-v node



(b) s-a nodal conduction time



(c) increased ventricular contraction



(d) time interval between onset of ventricular contraction.

Answer 1

Answer:

b)s-a nodal conduction time.

Explanation:

here though the qustn is not appropriate as the p-r interval comprises of the P-wave and the QR-wave

the Pwave is the firing of SAN and depolarisation of atrial muscle i.e atrial systole

the QRS wave is known for its ventricular event  it is the firing of AV node and ventricular depolarization

while time delayed or the av nodal rythm in av node is the cause of inverted P-wave

thus the whole pr interval is the starting of SAN or the s-a nodal rythm to ensure the atrial systole