Cardiac Physiology

Question 1

What can you determine from invasive arterial monitoring?

Answer 1

(1) arterial blood pressure
(2) myocardial contractility, which is represented by the slope of the upstroke
(3) systemic vascular resistance, which is represented by the slope of the diastolic decay

Question 2

What is the dicrotic notch?

Answer 2

Represents closure of the aortic valve and subsequent retrograde flow of blood against the closed valve. Occurs at the end of ventricular systole.

Question 3

Where should a central venous line sit?

Answer 3

The tip of the central venous line should sit at the junction of the SVC and RA, ~15-18cm from the point of entry.

Question 4

What is the JVP nomenclature?

Answer 4

a wave = atrial systole

c wave = isolvolumetric contraction of the RV with bulging of the closed TV, resulting in a small rise in RA pressure

x descent = atrial diastole, relaxation of the atrial muscle results in reduced RA pressure

v wave = venous return against a closed TV

y descent = opening of the TV resulting in emptying of the RA