VALSALVA MANOUVERE

Question 1

What are the key points of the Frank-Starling mechanism?

Answer 1

• Stretching the heart muscle leads to a more forceful contraction.
• The optimal stretch occurs when the heart muscle is stretched to a certain point—too much or too little stretch can reduce efficiency.

-The Frank-Starling mechanism helps the heart adjust its pumping capacity to match venous return, maintaining a balance between blood inflow and outflow.

• It ensures proper cardiac output by adjusting stroke volume in response to changes in blood volume

Question 2

What is the Valsalva manoeuvre?

Answer 2

The Valsalva manoeuvre is a forced expiration against a closed glottis, leading to increased intrathoracic pressure and affecting the cardiovascular system.

Question 3

What are the common uses of the Valsalva manoeuvre?

Answer 3

1. To terminate an episode of supraventricular tachycardia.
2. To normalize middle-ear pressures.

Question 4

What happens in the first stage of the Valsalva manoeuvre?

Answer 4

There is an increase in intrathoracic pressure.

Question 5

How does increased intrathoracic pressure affect venous return in the Valsalva manoeuvre?

Answer 5

The increased pressure venous and right atrial pressure, reduces venous return to the heart.

Question 6

What effect does reduced venous return have on cardiac output during the Valsalva manoeuvre?

Answer 6

The reduced preload leads to a fall in cardiac output, due to the Frank-Starling mechanism.

Question 7

What happens when the pressure is released during the Valsalva manoeuvre?

Answer 7

There is a further slight fall in cardiac output due to an increase in aortic volume.

Question 8

What occurs after the Valsalva manoeuvre is completed?

Answer 8

A: Normal cardiac output returns to the system.