Valsvalva

Question 1

Phase 1 of valsalva manouvre

Answer 1

Onset of strain
increase intrathoracic pressure
transient ↑ arterial pressure, ↓ HR (baroreflex)

Question 2

Phase 2 of Valsalva manoeuvre

Answer 2

sustained strain
↓ venous return → ↓ CO → ↓ arterial pressure, ↑ HR (compensatory)

Question 3

phase 3 of valsalva manoeuvre

Answer 3

release of strain
Sudden ↓ intrathoracic pressure → ↓ BP briefly, ↑ venous return

Question 4

Phase 4 of valsalva maneouvre

Answer 4

Recovery
Rapid ↑ venous return and CO → overshoot in BP, reflex bradycardia