1. Ailin Barseghian El-Farra, MD Cath Lab Essentials January 23, 2016
Basic Hemodynamics
Ailin Barseghian El-Farra, MD
Cath Lab Essentials
January 23, 2016

2. Pressure is created by blood within the heart or vessels.

3. First cardiac catheterization and pressure measurement performed on a living animal
English physiologist Stephen Hales early in the 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

4. Right Heart Catheterization

5. INDICATIONS

6. Indications Diagnostic and therapeutic indications:
Differentiate cause of shock or pulmonary edema
Evaluation for pulmonary hypertension
Differentiation of pericardial tamponade from constrictive and restrictive cardiomyopathy
Diagnosis of left to right shunt
Guide fluid management and hemodynamic monitoring after surgery, complicated MI, shock, etc..

7. CONTRAINDICATIONS

8. Contraindications No absolute contraindications
CAUTION in patients with pulmonary hypertension and elderly
Left bundle branch block

9. EQUIPMENT

10. Equipment Catheter Transducer
Fluid-filled tubing to connect the catheter to the transducer
Physiologic recorder to display, analyze, print and store the hemodynamic waveforms

11. Equipment

12. TECHNIQUE

13. A Systematic Approach to Hemodynamic Interpretation
1. Establish the zero level and balance transducer. 2. Confirm the scale of the recording. 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

14. 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

15. Components of a Routine Complete Right- and Left-Heart Catheterization
1. Position pulmonary artery (PA) catheter. 2. Position aortic (AO) catheter. 3. Measure PA and AO pressure. 4. Measure thermodilution 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. 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. 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.

16. 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

17. CARDIAC CYCLE

18. 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
A wave

19. PRESSURE WAVE INTERPRETATION

20. The v wave is usually smaller than the a wave in the right atrium
Inspiration – x and y descent become more prominent on the RA waveform
Chronic afib – persistence of x descent despite loss of a wave

21. RV normal
RV pulm HTN
PA normal – dicrotic notch
PA – respiratory variation

22. Relationship b/w LA and PCWP waveforms
Note the time delay on PCWP for the same events and relatively “damped” appearance of the PCWP tracing with a slightly lower pressure compared with the LA pressure.

23. LEFT HEART CATHETERIZATION

24. Normal high fidelity aortic pressure wave form
Normal high fidelity aortic pressure wave form. Dicrotic notch represents sudden closure of the aortic valve
Prominent anacrotic “notch” or “shoulder” in a pt with severe aortic regurgitation. – may be observied in severe AS and indicates turbulence during ejection.
Pulsus alternans
Pulsus paradoxes – COPD
Spike and dome – HOCM
Pulsus parvus and tardus – aortic stenosis
M wave or W wave – tamponade

25. Marked elevated LVEDP in pt with HF

26. PITFALLS

27. Schematic
Underdamped will overestimate systolic pressure and underestimate diastolic pressure….
Overdamp wavefomr obsucres subtle hemodynamic findings (ie dicrotic notch).
-high fidelity tracing with dicrotic notch
Damped aortic pressure due to presence of an air bubble in the catheter – poor fidelity, smooth appearance, lacks dicrotic notch

28. Simultaneous aortic and femoral pressure – FA pressure wave has a time delay, peripheral amplification with higher systolic pressure and a “damped” appearance with loss of dicrotic notch. A simultaneous aortic and rdial pressure shows the typical “spiked” appearance of peripheral waveform.

29. ARTIFACTS

30. “whip” artifacts seen in pts with hyperdynamic hearts
A- PA waveform unrecognizable
B excessive catheter whip from prominent loop in rt atrium
C removal of loop improved the appearance of waveform
D but, overshoot artifact remained
E filter resulted in further improvement in appearance of waveform

31. CARDIAC OUTPUT

32. Cardiac Output
Thermodilution
Fick Method

33. Thermodilution Bolus injection of liquid Saline Proximal port
Change in temperature is measured by thermistor in the distal portion of the catheter

34. 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
Direct Fick: Vo2 measurement
Indirect Fick: Vo2 estimate (3.5 mL/Kg)
Cardiac Output
(L/min)

35. Limitations Thermodilution Fick Not accurate in TR
Overestimated cardiac output at low output states
VO2 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

36. THANK YOU

37. Normal Pressures Site Normal Value (mmHg) Mean Pressure (mmHg)
Saturation
Right Atrium (or CVP)
0-5
75%
Right Ventricle
25/5
Pulmonary Artery
25/10
10-20
PCWP
7-12
95-100% LV
120/10
Aorta
120/80

38. 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
L/min/m2
SVR
dynes sec/-cm5
PVR
<250 dynes sec/-cm5
MAP
mmHg

39. 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, Print.
Ragosta, Michael. Textbook of Clinical Hemodynamics. Philadelphia, PA: Saunders/Elsevier, Print.