Case study 5 - PSA

Page 1

Why is a murmur apparent in Rico?

Why is Rico's pulse described as bounding?

How has Rico's heart resided to the situation?

How will pulmonary circulation in Rico differ from normal? Can you explain these changes?

Page 2

Why is a murmur apparent in Rico?

turbulence

non laminar flow

valve incompetence, viscosity

Page 3

Why is Rico's pulse described as bounding?

strong

pulse pressure - high

diff between systolic and diastolic pressure = large

high pulse amplitude

diastolic pressure = happens when outlet valves closed

determined by TPR

pressure in closed system of tubes - depends on how tightly arterioles are constricting

low diastolic pressure in this situation

peak in pressure -> continual fall in BP

diastolic decay - tire puncture analogy

systolic - peak pressure as blood is ejected from the heart -> if higher - ejected more blood from the heart

increased EDV -> increased SV -> increased systolic pressure

Page 4

tie off vessel

systolic pressure remains high

still have high venous return and high EDV

will remain elevated

diastolic will increase

not getting leakage

Page 5

How has Rico's heart resided to the situation? How will pulmonary circulation in Rico differ from normal? Can you explain these changes?

pressure increased in L atrium and L ventricle

increase in flow in pulmonary circ

not much change in resistance

response of vascular bed to increase flow = vasoconstriction

leads to vascular modelling

chronic vasoconstriction

smooth muscle hypertrophy

increasing resistance

R heart - thinner wall

not designed to operating at high pressure

designed to have lower resistance

as pressure rises in pulmonary circ - pressure on R heart

if persists - pulmonary hypertension

pressure in R heart greater in L

physiological principles in clin observation

Page 6

seizures

poor perfusion of brain

potential mini thrombosis

hypoxia -> seizures