This document defines different hemodynamic waveforms and how to interpret them. There are three basic waveform morphologies: atrial, arterial, and ventricular. Atrial waveforms from the right and left atria are similar, as are waveforms between the pulmonary artery and aorta, and the right and left ventricles. The document describes how to measure central venous pressure using water manometers or electronic transducers, and interpret pulmonary artery catheter waveforms to evaluate pressures in the right atrium, right ventricle, and pulmonary artery.

2. By
Dr. Samiaa Hamdy Sadek
Lecturer of chest diseases
Assiut University

3. Definition:
 Hemodynamic waveforms are “maps” of the pressure
changes that take place within a given vessel or
chamber.
 All of the waveforms obtained from arterial lines,
pulmonary artery catheters, or during cardiac
catheterization can be recognized by recalling 3 basic
waveform morphologies.

4. These waveform shapes include:
1) Atrial
2) Arterial, and
3) Ventricular waveforms.
 Because both atria fill, empty and contract in the
same sequence during systole and diastole, the
right atrial and left atrial waveforms have similar
patterns.
 Similar changes occur between the pulmonary
artery and aorta, and the right and left ventricles.

5. pulmonary artery catheter (Swan Ganz)
 Standard PAC is 7.0, 7.5 or
8.0 French in circumference
and 110 cm in length divided
in 10 cm intervals.
 The catheter tip if properly
inserted, rests in a pulmonary
arteriole.
 Patency of the Distal lumen is
achieved by maintaining a
continuous flow of
heparinized saline at a rate of
3cc/hour.
Developed by Swan Ganz and
colleagues in 1970

6. pulmonary artery catheter (Swan Ganz)
 PAC has 4-5 lumens:
 Temperature thermistor located
proximal to balloon(blue arrow) to
measure pulmonary artery blood
temperature (yellow line)
 Proximal port located 30 cm from
tip for CVP monitoring, fluid and
drug administration (blue line)
 Distal port at catheter tip for PAP
monitoring (black arrow)
 +/- Variable infusion port (VIP) for
fluid and drug administration
 Balloon at catheter tip

7. Catheter component

8. Pulmonary artery pressure monitoring
system

9. Indications:
Diagnosis of shock
Assessment of fluid volume status
Measurement of cardiac output
Monitoring and management of haemodynamically
unstable patients
Assess diagnosis of primary pulmonary
hypertension, valvular disease, intracardiac shunts,
cardiac tamponade, and pulmonary embolus

10. Positioning of PAC
It may be easy to remember the ‘rule of 10’s

11. Measuring central venous pressure
1- Water manometers 2-Electronic pressure transducer
In contrast to electronic transducer water manometers
overestimate CVP by 0.5-5cm H2O

12. CVP Recording
The phlebostatic axis is the point where the fourth intercostal
space and mid-axillary line cross each other regardless of
head elevation.

13. Measuring CVP using a manometer
1. Line up the manometer
arm with the phlebostatic
axis .
2. Move the manometer
scale up and down to
allow the alignement with
zero on the scale. This is
referred to as 'zeroing the
manometer

14. 3. Turn the three-way tap off to
the patient and open to the
manometer.
4. Move the manometer scale up
and down to allow the bubble
to be aligned with zero on the
scale. This is referred to as
'zeroing the manometer'.Open
the IV fluid bag and slowly fill
the manometer to a level
higher than the expected CVP
Measuring CVP using a manometer

15. 5. Turn off the flow from
the fluid bag and open
the three-way tap from
the manometer to the
patient
6. The fluid level inside the
manometer should fall
until gravity equals the
pressure in the central
veins
Measuring CVP using a manometer

16. 7. When the fluid stops
falling the CVP
measurement can be
read. If the fluid moves
with the patient's
breathing, read the
measurement from the
lower number
8. Turn the tap off to the
manometer
Measuring CVP using a manometer

17. Measuring CVP using electronic transeducer
The electronic transducer is a device that converts
mechanical energy into an electrical waveform that is then
displayed on the monitor as a waveform.
These waveforms represent changes in pressure and are the
result of physiological events, such as contraction of the heart.
In order for the transducer to the supply the monitor with
information that is clinically relevant to the monitor the
transducer must be zeroed correctly and leveled at a known
reference point.

18. 1. The CVC will be
attached to intravenous
fluid within a pressure
bag. Ensure that the
pressure bag is inflated
up to 300mmHg.
2. Place the patient flat in a
supine position if
possible. Alternatively,
measurements can be
taken with the patient in
a semi-recumbent
position.
Measuring CVP using electronic transeducer

19. 3. Tape the transducer to
the phlebostatic axis or
as near to the right
atrium as possible.
4. Turn the tap off to the
patient and open to the
air by removing the cap
from the three-way port
opening the system to the
atmosphere.
Measuring CVP using electronic transeducer

20. Measuring CVP using electronic transeducer

21. 5. Press the zero button
on the monitor and
wait while calibration
occurs.
Measuring CVP using electronic transeducer

22. 6. When 'zeroed' is
displayed on the
monitor, replace the
cap on the three-way
tap and turn the tap
on to the patient.
Measuring CVP using electronic transeducer

23. 7. Observe the CVP
trace on the monitor.
The waveform
undulates as the
right atrium
contracts and
relaxes, emptying
and filling with
blood. (light blue in
this image)
Measuring CVP using electronic transeducer

24. Waveform recognition:
1. Atrial pressure waveforms (right atrial,
PAWP):
Waveforms obtained from the right and left atria have
similar morphologies. Thus, CVP (right atrial) and left atrial
pressure tracings have similar shapes.
Pulmonary artery wedge pressure waveforms (PAWP) are
indirect measurements of the left atrial pressure. Thus, CVP
and PAWP waveforms have similar shapes.
The right-sided pressures are slightly lower than the left.

25. Atrial pressure waveforms
CVP shows three positive
waves (a, c, v), and two
descents (x, y).
a wave represent
increase in atrial
pressure as a result of
atrial contraction and
pumping of blood in
right ventricle.
Begins in the PR interval
and QRS on the ECG

26. Atrial pressure waveforms
c wave result from
increase of right atrial
pressure as a result of
closure of tricuspid
valve.
Observed in ST segment,
may or may not present.
v wave is the rise in
atrial pressure as it
refills during ventricular
contraction.
V wave correlates with T
wave in ECG.

27. Atrial pressure waveforms
Following contraction, the
atria begin to relax, and the
atrial pressures once again
fall.
This fall in atrial pressures
is identified by the down
slope of the “a” waves. This
is referred to as the “X”
descent.
 Opening of tricuspid and
mitral valves during early
diastole produce rapid
decline in atrial pressure
represented by “Y” descent.

28. Correlation to ECG
First locate the “v” wave. It will
appear immediately after the “T”
wave on a CVP waveform,
however, it will be .08-.12 seconds
after the T wave on a PAWP
tracing.
If the patient has a sinus rhythm,
an “a” wave should be in the PR
interval for a CVP. It is later in
the PAWP.
If present, the “c” wave is
generally within the QRS for a
CVP. It will be after the QRS for a
PAWP .

29. Measuring CVP and PAWP
Normal CVP 0-8 mmHg,
normal PAWP 8-12mmHg.
Measure atrial pressure at
end diastole which identified
by mean of the highest and
lowest “a” wave.
Another way is Z-line(line
from end of QRS to atrial
tracing) it is delayed 0.08-
0.12 sec from QRS for PAWP.
Z line

30. Normal Value 8-12
mmHg.
The average of the
highest and lowest
value of a wave.
Using z line which
delayed 0.08-0.12sec
after QRS.
Measuring PAWP

31. PEEP and PAWP
PAWP is not affected by PEEP pressures less than
10cm H2O. With PEEP pressures greater than 10, the
pulmonary vasculature is compressed and the alveolar
and intrathoracic pressure increased, thereby affecting
the accuracy of the PAWP measurement.
Calculation of PAWP with high levels of PEEP:
1. Convert the applied PEEP from centimeters of water to
millimeters of mercury (1.36 cm H2O = 1 mm Hg)
2. Subtract half the applied PEEP in millimeters of mercury
from the measured PAWP

32. 2-Ventricular pressure wave forms:
During early diastole, the ventricles relax and
stretch so the pressure in the ventricles remain
very low.
In late diastole, atrial contraction forces a
“bolus” of blood into the ventricles, which can
causes a small rise in the ventricular pressure.
At the end of diastole ventricles begin to
depolarize and ventricular pressure exceed
atrial pressure, AV valves close while
pulmonary and oartic valves also
closed(isovolumetric contraction) with sharp
rise in ventricular pressure.

33. 2-Ventricular pressure wave forms:
As soon as the ventricles contract, blood leaves
the ventricles, causing the ventricular pressures
to begin to fall
At end systole, the ventricles begin to stretch
and relax, and the ventricular pressures fall to
the their lowest point.
Detection of right ventricular pressure rise
using PAC is delayed after QRS in comparison
to direct detection which occur with QRS
complex.

34. Measuring RV pressure
Normal Value 15-25/0-8
mmHg.
Systole measured at the
peak which occurs after
the QRS
Diastole measured just
prior to the the onset of
systole

35. Arterial waveforms
As the ventricles contract, they eject blood
into the pulmonary artery and aorta. This
causes an immediate rise in the arterial
pressure.
Late in systole, the rate of ejection slows as
the pressure gradient between the
ventricles and arteries narrow, so the
pressure begins to decline. This causes the
early downslope in the arterial tracing

36. Arterial waveforms
The ventricles begin to relax, causing the
ventricular pressures to drop below the
pressures in the great vessels. This causes
the pulmonic and aortic valves to close,
producing a dicrotic notch.
Following closure of the semi-lunar valves,
the pulmonary artery and aortic pressures
continue to fall as blood leaves the great
vessels to perfuse the tissues and lungs.

37. Measuring pulmonary artery pressure
Normal Value 15-25/8-15
mmHg.
Systole measured at the
peak of the wave
Diastole measured just
prior to the upstroke of
systole (end of QRS)
Higher than RV diastolic
pressure

38. Differentiating the Right Ventricle and
Pulmonary Artery Waveforms
The wave looks taller.
The systolic pressure equals the previously
recorded pulmonary artery systolic pressure.
The diastolic pressure matches the right atrial
diastolic pressure.
Inflation of the balloon fails to produce a
PAWP waveform.
 The waveform is symmetrical in shape.
 There is no dicrotic notch.
 A small preliminary rise in late diastole is
present prior to the main rise in the pressure
waveform.
 The new pressure is closer to the QRS than the
previous pulmonary artery tracing.
RV waveform
PA Waveform

39. Pulmonary artery catheter waveforms
RA RV PA PAWP

40. Thank you