Right Heart Cath, Swan Ganz

 https://www.youtube.com/watch?v=26aec9AM8kA&ab_channel=RobAttaran

this is an introduction to right heart

catheterization during a right heart

catheterization you are passing a

catheter from the right atrium into the

right ventricle pulmonary artery and

subsequently into the wedge position

each chamber and segment has a typical

and normal pressure range there are all

Indications

sorts of indications for right heart

catheterization a key one is to

determine the cause of shock it can also

be used to evaluate hemodynamics and

valvular heart disease extent of

shunting pre heart transplant evaluation

and let's not forget evaluation of

pulmonary hypertension whether there is

a true absolute contraindication to

right heart catheterization is open to

debate certainly if there is significant

endocarditis thrombus or mass in the

right heart caution must be exercised

there are a number of relative

contraindications that you will see here

some may argue that a significant

pulmonary embolism may be a

contraindication

although measurement of PA pressure

invasively can often be a part of

catheter directed thrombolysis protocols

and lastly if a patient already has a

left bundle branch block performing

right heart catheterization may on

occasion induce transient complete heart

block complications of

heart catheterization are very rare on

occasion you may trigger an arrhythmia

and very rarely cardiac perforation may

occur if there is overly zealous

technique perforation and rupture of the

pulmonary artery is rare but if it

occurs it's a devastating complication

here is a list of the rest there are a

Access sites

number of possible access sites such as

the internal jugular basilic vein or the

subclavian vein you can also use the

femoral vein at our Center if you're

going to leave a swan-ganz catheter in

place and send the patient up with it

the internal jugular vein is the typical

mode of access we perform all internal

jugular access with ultrasound after

prepping and draping the area the

patient's head is tilted away and by

ultrasound which will be shown to you

separately the internal jugular vein and

the carotid arteries are clearly

identified and access is facilitated a

Wedge catheter

right heart catheterization can be

performed with this simple wedge

catheter it effectively has only two

ports the one below to inflate the

balloon and the one above for drawing

blood or injecting the balloon that is

inflated is near the very tip of the

device and we typically inflate the

balloon and allow the flow of blood to

help move the device into the pulmonary

artery position when we have to leave in

Swanganz catheter

a catheter we typically use the more

complicated swan-ganz device if you look

more closely you will see that it has

where the three arrows are three ports

for drawing

blood or for injecting when this device

is in place the PA distal port

communicates with the tip of the

catheter you can draw blood from the

very tip for instance when you'd like to

obtain oxygen saturations from the

pulmonary artery the RV infusion port

communicates with the right ventricle

and the proximal injected port typically

is positioned within the right atrium

when in place if you look carefully

towards the center and left of this

diagram you will see where the output of

the RV infusion and the proximal inject

aids are the blue arrow shows the

balloon inflation port the next blue

arrow towards the right shows a

connector this can be plugged into a

circuit that can help calculate cardiac

output using thermodyne you sure as

you'll soon find out there are two broad

ways to calculate cardiac output with a

swan-ganz catheter one is using the Fick

method where oxygen saturations are

obtained and the other is through

thermal with the thermodyne method

saline typically at room temperature is

injected at the proximal injected site

then the thermocouple shown by the green

arrow will detect temperature changes

and calculate cardiac output now the

How to float

easiest way to float a swan is from

above from the internal jugular vein it

will likely follow the flow and insert

quite easily with minimal manipulation

you may not even require fluoroscopy but

Pressure tracing

let's assume for a moment that you're

performing right heart catheterization

from below from the common femoral vein

this typically requires more catheter

manipulation and it can be more

challenging the key with any right heart

catheterization is to look at the

pressure tracing so you know whether

you're in the right atrium or in the

right ventricle and so on an important

bit of advice is to ensure that your

catheter is placed into the RV as you

see here and that the balloon starts to

not upwards this is what I call the

sweet spot

you

you will have the best chance of getting

your right heart catheter into the

pulmonary artery by maintaining and

working from the sweet spot that I

described where you will see the nodding

action if you were to advance your

catheter further in you're likely to get

caught in the wall or in perhaps some

valvular apparatus and you're less

likely to be able to float upwards

now once you are in the sweet spot area

the best thing to do is to clock your

wedge catheter until it starts to look

up and then you should quickly make use

of the opportunity and push the catheter

into the PA

if clocking does not work then counter

clock rotation can sometimes do the

trick

now as you float a swan you will have

the tip connected to the transducer so

you can see the typical pressure

waveforms seen at the tip and as you can

see on the very left the Swan tip is

within the right atrium and you can see

the corresponding pressures below as you

float the Swan into the right ventricle

the pressure waveform changes with high

systolic up strokes but the diastolic

values remain low because this is a

ventricular waveform as you float up

into the pulmonary artery now you have

an arterial waveform so the diastolic

values as you can see are higher and now

you have a dicrotic notch next as you

advance the tip into the pulmonary

artery branches and cause a wedge

tracing you can see a much more flat

waveform the right atrial and by

extension the jugular waveforms are

demonstrated here please pause this

video for a moment just to refresh

yourself but bear in mind that during

right heart catheterization it is

essentially impossible to identify every

waveform typically the mean right atrial

pressure is measured

should the patient have significant

tricuspid regurgitation then you will

have large prominent CV waves 

and you

can document their value separately you

will also be familiar of course with the

X&Y descents that referred to atrial

relaxation and emptying for emphasis

Additional slides

here are some additional slides to show

typical right heart pressures these are

from a different source so the numbers

are slightly different but in general

are a pressures are 5 or below RV around

normal pulmonary artery wedge pressures

are around 8 to 12 

as a general rule it

is advisable in non ventilated patients

to measure and document these pressures

at the end of unforced exhalation now

while an RA pressure speaks to

right-sided filling pressures and wedge

pressure speaks to left-sided filling

pressures in fact a PA wedge pressure

corresponds closely to the LV and

diastolic pressure in the cath lab we

use the fig principle to work out

cardiac output more than any other the

fig principle states that blood flow to

an organ can be calculated using a

marker substance if the following bits

of information are known the amount of

marker substance taken up by the organ

per unit time the concentration of the

marker substance in the arterial blood

supply in the organ and the

concentration of the marker substance in

the venous blood leaving the organ put

another way

cardiac output can be estimated by

oxygen consumption rate divided by the

difference in arterial venous oxygen

content

our markers substance is obviously

oxygen here is the equation I would like

you to use to calculate cardiac output

using the fig method in the cath lab

because measuring actual oxygen

consumption can be onerous this is an

estimate where a hundred and twenty five

mils is multiplied by body surface area

to give you the oxygen consumption

estimate so if an individual had a BSA

of two their vo2 would be 250 now when

you perform right heart catheterization

you can obtain oxygen saturations from

the pulmonary artery position and that

would correspond to the svo2 that you

see in the denominator arterial oxygen

saturations such as those obtained from

the aortic position will give you the SI

Fick Principle

CO = O2 consumption / Change in O2 Content

O 2 as you can see you also need the

value of hemoglobin and the 1.36 is a

correction that applies to oxygen

content pertaining to blood or

hemoglobin so let's imagine we have a

patient with a body surface area of two

an AO saturation of 98% pa saturation of

familiarized yourself with this method I

would like you to pause and calculate

correct output for yourself but please

remember that for the saturation values

in this equation you cannot enter 65%

but rather 0.65 and you cannot enter 98%

but rather 0.98 so please pause and work

out the fig card

output here

you should obtain the following numbers

and as a result the cardiac output would

be calculated at five point one liter

per minute now imagine the scenario only

the PA sat was lower say 50% putting

that into the formula would give you a

larger denominator and as a result a

lower cardiac output calculating cardiac

Cardiac Index

index merely requires that you divide by

body surface area the top two rows show

once again the equations that you have

seen already

once you have cardiac output you can

also work out systemic vascular

resistance and pulmonary vascular

resistance to work out SVR map or mean

arterial pressure is used and from that

you deduct right atrial pressure

dividing that by cardiac output

multiplying by eighty as shown pulmonary

vascular resistance is worked at by

taking mean PA pressure deducting

pulmonary artery wedge pressure and

dividing that by cardiac output and

multiplying by eighty however in the

cath lab the standard units of measure

are a little different we do not

multiply by eighty and the number that

we obtain is given in wood units though

Units of measure

we strongly recommend that you work out

these values yourself there are apps

available they can help you patients in

Chest xrays

the CCU who receive a swan-ganz catheter

typically get chest x-rays on a frequent

you can look at these images to ensure

that the Swan appears to be where it

should be and that there's no kinking

and the tip has not extended too far

beyond the midline in addition to x-ray

PA waveforms

imaging the waveforms picked up on the

Swan ports can give clues on its

location if you cannot get a PA waveform

it is possible that the Swan tip has

moved or perhaps dropped into the right

ventricle in those situations a number

of things can be tried like deflating

the balloon and re-inflate again trying

to advance the device ultimately if the

waveforms are lost and cannot be

regained it might be necessary to

position another Swan this light is a

wonderful summary explaining some of the

concepts that we've talked about as a

Recap

final recap my friends I would like to

remind you to get comfortable with the

appearance and nature of the waveforms

as you perform right heart

catheterization the right atrial

pressures are typically low and

relatively flat when you reach the right

ventricle there are broad up swings but

the diastolic pressures are still

relatively low as you successfully reach

into the pulmonary artery the diastolic

values start to rise and you may see a

dicrotic notch and finally as you

advance your balloon further and obtain

a wedge tracing once again the waveform

becomes flatter though there are

exceptions such as in cases where a

giant V wave occurs some patients

CardioMEMS

receive the tiny cardio MEMS device in

their

my arteries this device can record

pulmonary artery systolic and diastolic

pressures and the PA diastolic pressure

can correspond to wedge pressure for

many patients

but despite the advancement of

technology including imaging right heart

catheterization is still performed quite

often and you will have the opportunity

to participate in many of these

procedures thank you very much for your

attention