Transcript Basic Hemodynamics - UC Irvine`s Department of Medicine

Cath Lab Essentials:
Basic Hemodynamics for the
Cath Lab and ICU
Ailin Barseghian El-Farra, MD, FACC
Assistant Professor, Interventional Cardiology
University of California, Irvine
Department of Cardiology
First cardiac catheterization and pressure
measurement performed on a living animal
– English physiologist Stephen Hales
– Early 1700s
– “By accessing the internal jugular vein
and carotid artery of a horse, Hales
performed his experiments using a brass
pipe as the catheter connected by a
flexible goose trachea to a long glass
column of fluid. The pressure in the white
mare’s beating heart raised a column of
fluid in the glass tube over 9 feet high.”
Reported in the book Haemastaticks in 1733; Hall WD. Clin. Cardiol. 1987:10;487-9.
Right Heart Catheterization
INDICATIONS
•
•
•
•
•
Cause of shock
Pulmonary hypertension
Guide fluid management
Left to right shunt
Pericardial tamponade vs constrictive and
restrictive cardiomyopathy
CONTRAINDICATIONS
• ABSOLUTE
– none
• CAUTION
– pulmonary
hypertension
– elderly
– left bundle branch
block
EQUIPMENT
• Catheter
• Fluid-filled tubing to
connect the catheter
to the transducer (A)
• Transducer (B)
• Physiologic recorder
to display, analyze,
store waveforms (C)
B
C
A
EQUIPMENT
http://thoracickey.com/hemodynamic-monitoring/
Systematic Hemodynamic Interpretation
1. Establish the zero level and balance transducer
2. Confirm the scale of the recording
-40 mmHg for RHC, 200 mmHg for LHC
3. Collect hemodynamics in a systematic method
using established protocols
4. Critically assess the pressure waveforms for
proper fidelity
5. Carefully time pressure events with the ECG
6. Review the tracings for common artifacts
Components of a Right Heart
Catheterization
1. Right atrium
– Mean (1-5 mmHg)
2. Right ventricle
– Phasic (25/5 mmHg)
3. Pulmonary capillary wedge
– Mean (7-12 mmHg)
4. Pulmonary artery
– Phasic and mean (25/10 mmHg; mean 10-20
mmHg)
PRECAUTIONS
• Always record pressures at end-expiration
(unless on PEEP)
• During inspiration, pressures will be lower due
to decrease in intrathoracic pressure
(assuming normal conditions)
• Always zero and reference the system
Components of a Routine Complete
Right- and Left-Heart Catheterization
1. Position pulmonary artery (PA) catheter.
2. Position aortic (AO) catheter.
3. Record PA and AO pressure
4. Measure thermodilution (x3) cardiac output.
5. Measure oxygen saturation in PA and AO blood samples to determine Fick output and
screen for shunt.
6. Enter the left ventricle (LV) by retrograde crossing of the AO valve.
7. Advance PA catheter to pulmonary capillary wedge position (PCWP)
8. Measure simultaneous LV-PCWP (mitral valve assessment).
9. Pull back from PCWP to PA.
10. Pull back from PA to right ventricle (RV) (to screen for pulmonic stenosis) and record RV.
11. Record simultaneous LV-RV (constriction vs restriction).
12. Pull back from RV to right atrium (RA) (to screen for tricuspid stenosis) and record RA
13. Pull back from LV to AO (to screen for aortic stenosis).
“Once the catheter was in place,
all lights in the room were
turned off, and the Hamilton
manometer (which focused a
light on sensitive paper to record
the pressure contour) was
attached to the catheter and
manipulated in absolute
darkness so that its light output
could be captured with a
handheld mirror and adjusted to
strike the paper. Researchers
could then record intravascular
pressures.”
Enson Y, Chamberlin MD. Cournand and Richards and the Bellevue Hospital Cardiopulmonary Laboratory. Columbia Magazine, Fall 2001.0000
CARDIAC CYCLE
Phase 1: atrial contraction
Phase 2: isovolumic contraction
(TV/MV closure
to PV/AV opening)
Phase 3: rapid ejection
Phase 4: reduced ejection
(PV/AV opening to
PV/AV closure)
Phase 5: isovolumic relaxation
(PV/AV closure to
TV/MV opening)
Phase 6: rapid ventricular filling
Phase 7: reduced ventricular
filling
(TV/MV opening to
TV/MV closure)
PRESSURE WAVE INTERPRETATION
RIGHT ATRIUM
RIGHT VENTRICLE
PULMONARY ARTERY
PULMONARY CAPILLARY WEDGE PRESSURE
LEFT HEART CATHETERIZATION
AORTIC
PRESSURE
LEFT
VENTRICLE
Kern MJ. Right Heart Catheterization. CATHSAP II CD-ROM. Bethesda, ACC, 2001.
PITFALLS
A
R
T
I
F
A
C
T
S
CARDIAC OUTPUT
• Thermodilution
• Fick Method
THERMODILUTION
• Bolus injection of liquid
– Saline
– Proximal port
• Change in temperature
is measured by
thermistor in the distal
portion of the catheter
FICK PRINCIPLE
• Described in 1870
• Assumes rate of O2
consumption is a
function of rate of
blood flow times the
rate of O2 pick up by
the RBC
Cardiac
Output
(L/min)
Oxygen consumption
-Direct Fick:
--Directly measured
-Indirect Fick:
--125 ml/min/m2 (avg)
--110 ml/min/m2 (elderly)
LIMITATIONS
Thermodilution
Fick
• Not accurate in TR
• Overestimated cardiac
output at low output
states
• Oxygen consumption is
often estimated by body
weight (indirect method)
rather than measured
directly
• Large errors possible with
small differences in
saturations and hemoglobin.
• Measurements on room air
THANK YOU
Normal Pressures
Site
Normal Value Mean
(mmHg)
Pressure
(mmHg)
0-5
Right Atrium
(or CVP)
Right Ventricle 25/5
Pulmonary
Artery
PCWP
LV
Aorta
25/10
7-12
120/10
120/80
Saturation
75%
75%
10-20
75%
95-100%
95-100%
95-100%
Normal Values
Site
Value
Sv02
0.60-0.75
Stroke Volume
60-100 ml/beat
Stroke Index
33-47 ml/beat/m2
Cardiac Output
4-8 L/min
Cardiac Index
2.5-4.0 L/min/m2
SVR
800-1200 dynes sec/-cm5
PVR
<250 dynes sec/-cm5
MAP
70-110 mmHg
References
• Bangalore and Bhatt. Right heart catheterization,
coronary angiography and percutaneous
coronary intervention. Circulation, 2011; 124:
e428-e433.
• Kern, Morton J. The Cardiac Catheterization
Handbook. Philadelphia, PA: Saunders Elsevier,
2011. Print.
• Ragosta, Michael. Textbook of Clinical
Hemodynamics. Philadelphia, PA:
Saunders/Elsevier, 2008. Print.