What energies does the transducer convert from - to?
Physical pressure - Electrical stimulus
How will the calibration square appear if underdamped?
Bow down
How will the calibration square appear if overdamped?
Bend upwards
How will the pressure tracing look if underdamped?
Give wavey pressure lines
How will the pressure tracing look if overdamped?
Be slurred
Explain the seldinger method:
Insert Syringe into femoral artery
Insert guide wire
Remove syringe
Insert Sheath
Remove guidewire
Insert catheter through sheath
What is the purpose of the guide wire:
Provide regidity whilst advancing the catheter
What are vessels advancing off the LAD called?
Diagonals
What are vessles advancing off the circumflex called?
Marginals
What is the quation for calculating Pressure mean (Pmean):
Pmean = ((2 x Diastolic) + Systolic)/3
How is the mean pressure calculated from 120/80mmHg
((2x80) + 120)/3 = 280/3 = 93mmHg
What is the anachrotic notch?
First phase of V systole (isovolumetric contraction) a presystolic rise in pressure may be seen before opening of the aortic valve
What does the Dichrotic nitch symbolise?
End of systole and beginning of diastole
What is the quation for pulse pressure?
Systolic - diastolic = PPressure
What shows diastolic dysfunction on the LV pressure trace?
Upsloping gradient from beginning diastole to beginning of systole
What is the post A wave also known as?
End diastolic pressure (reflective of A pressure)
What different landmarks are seen on the atrial waveform?
A
C
X
V
Y
What is the A wave?
Increase in A Pressure during A contraction
What is the X descent?
Drop in pressure following A relaxation
What is the C wave?
May come as an interruption to the x descent respresenting the movement of the AV valve towards the atrium in AV closer (beginning of isovolumetric V contraction)
What is the V wave?
Increase in pressure during V systole, causing the AV valve to bulge into the atrium
Where would the V wave be exaggerated?
AV valve regurgitation
What may cause differences in RV-LV pressures?
Constrictive Pericarditis
BBB
Pulm Hypertension
MI
What are the normal pressures for LV:
100-140mmHg Systolic
60-90mmHg Diastolic
Normal pressure for RA?
4-9mmHg
Normal pressure for RV:
20-30/5mmHg
Normal pressure for PA:
20-30/15mmHg
What is the purpose of a Pulmonary capillary wedge?
Indirect measure of left atrial pressure
How is a PCW peformed:
RA - RV - PA - Wedged in PCs
Explain PA - RV pullback
No gradient systolic pressure
Explain RV - RA pullback
No gradient in diastolic pressure
Pressure in PA is 20mmHg
Pressure in RV is 40mmHg
Whats the diagnosis?
Pulmonary stenosis
Pressure of RV is 20/5
Pressure in RA is 10
Whats the diagnosis?
Tricuspid stenosis
Pressure in Ao is 170/70
Pressure in LV is 200/10
Whats the diagnosis?
Mixed valvular disease
Difference in systolic pressure suggests Ao Stenosis
Difference in diastolic pressure suggests Ao regurgitation
Whats a normal LV - Ao pullback?
No change in systolic pressure
What does the area under the graph for LV on Ao suggest?
Mean gradient is difference between LV/Ao during the open Ao valve
Normal valve area should be?
2.5-5cm2
What does a slow upsloping rise in Ao pressure suggest?
Ao Stenosis
What does a large pulse pressure suggest?
Regurgitation
How can you tell mitral stenosis from pressure traces?
PCWP > EDP
Due to increase in LA pressure
From a pressure trace, how is mitral regurgitation seen?
Large V wave (due to backflow of blood and hence increase pressure in LA) on PCWP trace on LV trace