Download Abnormal Hemodynamics

Abnormal Hemodynamics
Darren Powell, RCIS, FSICP
Blaufuss Multimedia - Heart Sounds CD
Disclosure Statement for Darren Powell
• No disclosures
Topics
• The Physics of Blood Flow
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Turbulence - Murmurs

Gradients
• Recognize Abnormal Hemodynamics

Stenosis

Regurgitation
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Focus on ASD Shunts
Cardiac Anatomy
Blaufuss Multimedia - Heart Sounds CD
Laminar Flow
Cardiovascular Physiology 8th ed Page 119
Turbulence
Cardiovascular Physiology 8th ed Page 126
Physics of Blood flow
Effect of velocity on pressure
Cardiovascular Physiology 8th ed Page 117
Aortic Stenosis
Cardiovascular Physiology 8th ed Page 119
Poiseuille’s Law
• Q= (Pi-Po) π r4
•
8nl
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Q = Flow through system
Pi = Pressure into the system
Po = Pressure out of system
π = pi
• r = Radius raised to the 4th power
• n = Viscosity of fluid
• l = Length of tube
Physics Summary
• Laminar flow is more efficient than
turbulent.
• Radius of tube is the most important
variable in determining flow/gradients.

True in valves for AS but also in the
LAD for an ACS patient
The Wiggers Diagram
Blaufuss Multimedia - Heart Sounds CD
Hemodynamic Theorems
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Valves open and close due to pressure gradients.
When pressure lines cross, valves are opening or closing.
To evaluate a valve you must know the pressure on both sides.
MV&TV are open in diastole/closed in systole.
AV & PV are open in systole /closed in diastole.
Stenosis shows when valves are open. Potential to kinetic =
gradient/ pressure step-down
• Regurgitation shows when valves are closed. Large pulse
pressure or large V waves = triangles
Normal Valve areas/adult
Aortic
Mitral
• Normal = 2.5 Cm2 • Normal = 5.0 Cm2
• Critical=0.5-0.8 Cm2 • Critical = 1.0 Cm2
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Aorta twice as large
Read the Echo report
Calibrate transducers
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Critical when 1/5th normal
Temporal alignment with
CO and Gradient
Calcific Acquired AS
www.pathology.vcu.edu
Aortic Stenosis :
• LV-Ao pressure gradient
throughout systole
– murmur occurs w/ upstroke
CW Doppler:
• high velocity outflow
– reaches peak of 5 m/sec
– est. 100 mmHg gradient
Severe AS:
• LV pressure rises
– increases LV-Ao gradient
• murmur peaks later
Blaufuss Multimedia - Heart Sounds CD
Hemodynamic effects of heart rate
80 bpm:
• tachycardia exacerbates LA
emptying dysfunction
• loud S1
• loud MDM, PSM
110 bpm:
• loud murmur was thought to be
systolic by house staff
• murmur ends with loud S1
• mid-diastolic murmur
66 bpm:
• each component can be heard
• loud S1, S2/OS, MDM, PSM
Chronic vs. Acute Aortic
Regurgitation
Chronic:
• at Base:
– MSM (Ao outflow)
– EDM (Ao regurgitation)
• at Apex:
– Austin Flint (mitral inflow)
– “split” S1 (S1 + ejection sound)
Acute:
• at Base:
– MSM (Ao outflow)
– EDM is abbreviated
• at Apex:
– Austin Flint (mitral inflow)
– absent S1 (ejection sound only)
Hemodynamics of Acute and
Chronic
Normal:
• S1, S2, no murmurs
Mitral valve prolapse:
• midsystolic click, possible late
systolic murmur of MR
Acute MR:
• here, from chordal rupture
• loud S1, initiates explosive
systolic murmur
• S3 with mid-diastolic murmur
Compensation:
• increased compliance of LA, LV
• blowing holosystolic murmur
• mid-diastolic rumble
Intra Cardiac Shunts
Normally Pulmonary Flow = Systemic Flow
QP = QS
Pulmonary
Artery
Pulmonary
Venous
O2 sat
O2 sat
Systemic
Venous
O2 sat
Systemic
Arterial
Flamm
O2 sat
Intra Cardiac L to R Shunts
Acyanotic
Pulmonary Flow greater than Systemic Flow
QP > QS
Elevated
PA O2 sat
PV
O2 sat
SV
SA
O2 sat
O2 sat
Intra Cardiac R to L Shunts
Cyanotic
Systemic Flow greater than Pulmonary Flow
Qp < Qs
PA O2 sat
Pulmonary
Venous
O2 sat
SV
O2 sat
Decreased
SAO2 sat
ASD- Anatomy/Prevalence
• Secundum 75%
• Primum 15%
• Sinus Venosus 10%
• Cor Sinus (rare)
Braunwauld’s Heart Disease, 6th ed
Cardiac Output = CO
• CO is the blood flow out
of the heart in L/min
• Normal CO is 5 L/min
(CI=2.5-4.0 L/min/ M2 )
• Qs is SBF (systemic
Blood Flow) = 5 L/min
• Qp is PBF (Pulmonic
Blood Flow) = 5 L/min
• Qp:Qs Ratio (5:5) =1:1
Shunt Example
• Qp is PBF (Pulmonic Blood
Flow) = 12 L/min
• Qs is SBF (systemic Blood
Flow) = 4L/min
• Qp:Qs Ratio (12:4) =3:1
• Absolute shunt (PBF-SBF)
12-4=8 lpm
• % shunt (PBF-SBF/PBF)
12-4/12
8/12=67%
Question
• Here are the sats: IVC=78% RA=85%,
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RV=86%, PA=85%LV=98%,DescAo=98%.
The PBF = 6 l/m and SBF = 4 l/m. Where is the
shunt and what direction?
a. ASD Rt to Lt
b. ASD Lt. to Rt
c. VSD Rt to Lt
d. VSD Lt to Rt
References
• Wes Todd CD
• Kern The Cardiac Cath Handbook
• Grossman/Baim Cardiac Catheterization,
Angiography, and Intervention
• Berne and Levy Cardiovascular Physiology
• Watson and Gorsky Invasive Cardiology A
manual for Cath Lab Personnel
• Blaufuss multimedia - Heart Sounds CD
Hemodynamics summary:
You’ve got to know where to look