Question
The ‘a wave’ in JVP is seen due to?
| A. |
Atrial contraction |
| B. |
Atrial relaxation |
| C. |
Ventricular contraction |
| D. |
Ventricular relaxation |
|
Correct Answer � A Explanation |
 |
– The ‘a wave’ in the jugular venous pulse (JVP) reflects right atrial contraction.
– It occurs just before the first heart sound (S1) and right after the P wave on the ECG.
– Right atrial contraction pushes blood into the right ventricle,
causing a temporary rise in right atrial pressure transmitted to the jugular vein as the ‘a’ wave.
Why Other Options Are Incorrect:
– B. Atrial relaxation: produces the x descent in JVP, not the a wave.
– C. Ventricular contraction: causes the ‘c’ wave from tricuspid valve bulging into right atrium.
– D. Ventricular relaxation: associated with the ‘v’ wave, due to passive atrial filling during diastole.