it it really low gradient? how severe is as? · low output low gradient as ... a1 x v1 = a2 x v2 v...
TRANSCRIPT
Low Output Low Gradient AS
Natesa G. Pandian
Disclosure: Speakers Bureau Lantheus Inc
AS Pressure Gradient
4 V 2
AS Pressure Gradient Max Instantaneous
Gradient Mean
Gradient Apical Suprasternal
How severe is AS? It it really low gradient?
Discrepancy between
Echo and Cath
Aortic Stenosis
Mean Peak to Peak MIG
Pressure Recovery Phenomenon
Total E = kinetic E + P Total E = kinetic E, P
Pressure Recovery Phenomenon
Catheter
Doppler Total E = kinetic E + P Total E = kinetic E, P
Catheter
Doppler
Issue in Small aortas Mod to severe AS
Pressure Recovery Phenomenon
Catheter
Doppler
Issue in Small aortas Mod to severe AS Correction:
Energy Loss Coef =
EOA x Aa/Aa-EOA
Pressure Recovery Phenomenon Aortic Valve Area Calculation
Continuity Equation “What goes in must come out”
Ao Valve Area by Continuity Equation
V1 V2
V1 A1 x V1 = A2 x V2
V2
Ao Valve Area by Continuity Equation
V1 V2
V1
Ao Valve Area = LVOF area x TVI1
TVI2
A1 x V1 = A2 x V2
V2
Aortic Valve Area by TEE
Surgical AVA
TEE AVA
Kasliwal/Trehan/Pandian
Echocardiography
Potential Errors
• LV outflow measurement
• Proximal flow velocity recording
• Maximum velocity recording
• Inaccuracy related to flow
Mild
Moderate Severe
Velocity (m/s) < 3.0 3.0 - 4.0 > 4.0
Mean Grad (mm Hg) < 25 25 - 40 > 40
Valve area (cm2) > 1.5 1.0 - 1.5 < 1.0
AVA index (cm2/m2) < 0.6
Echo Criteria for Severity of AS
Mild
Moderate Severe
Velocity (m/s) < 3.0 3.0 - 4.0 > 4.0
Mean Grad (mm Hg) < 25 25 - 40 > 40
Valve area (cm2) > 1.5 1.0 - 1.5 < 1.0
AVA index (cm2/m2) < 0.6
Echo Criteria for Severity of AS
“If the mean gradient is less than 40,
it can not be severe AS”
“If the mean gradient is less than 40,
it can not be severe AS” X Calculated relation of aortic valve area
to mean pressure gradient by cath
Carabello BA et al N Engl J Med 2002
Valve area and mean pressure gradient (dPm) with relationship to criteria for severe aortic stenosis.
Jander N Eur Heart J Suppl 2008;10:E11-E15
The issue of LVOT diameter
•Major cause for low output
•Underestimation of SV
•TEE if TTE is not good
Severe AS and Low Gradient
Does exist
Severe AS and Low Gradient
What are the mechanisms ?
Severe AS and Low Gradient
Systolic LV dysfunction,
Low Stroke Volume
1
73 Male Severe AS, EF 32, Severe HF, No CAD LV dysfunction
Low cardiac output
Low Velocity, Low Gradient
Mild AS
Severe AS Low SV
LV dysfunction
Low cardiac output
Low Velocity, Low Gradient
2 solutions for diagnosis
Low Velocity, Low Gradient
TEE planimetry
Of AVA
Dobutamine
Stress testing
Low EF, Low Gradient Severe AS
Management
Dobutamine Stress in Low Gradient AS in HF Patient
Optimal surgical candidate:
With Dobutamine, Mean gradient > 30 mm Hg AVA increase < 0.3 sqcm Stroke volume > 20%
If severe LV dysfunction with no reserve, then medical therapy
Low-gradient aortic stenosis: operative risk stratification and predictors for long-term outcome: a multicenter study
using dobutamine stress hemodynamics Monin JL, et al. Circulation 2003 ;108:319-24 Severe AS and Low Gradient
Increased Vascular Afterload
2
Systemic Hypertension in 30 – 50% of AS patients
Little SH, Chan KL, Burwash IG. Heart. 2007; 93(7):848-5
Impact of increasing arterial blood pressure in aortic stenosis
Normal arterial BP does not exclude increased vascular load because of pseudonormalization (30% of pts)
Aging
Hypertension
Atherosclerosis
Decreased compliance
Increased impedance
Normal arterial BP does not exclude increased vascular load because of pseudonormalization (30% of pts)
Aging
Hypertension
Atherosclerosis
Decreased compliance
Increased impedance
Normal arterial BP does not exclude increased vascular load because of pseudonormalization (30% of pts)
Aging
Hypertension
Atherosclerosis
Decreased compliance
Increased impedance
Normal arterial BP does not exclude increased vascular load because of pseudonormalization (30% of pts)
Aging
Hypertension
Atherosclerosis
Global hemodynamic
load (Valvuloarterial
impedance, Zva)
Valvuloarterial Impedance (Zva)
Systolic BP + Mean gradient
Stroke volume/Height
AS + Increased Vascular Load
Management
Severe AS Surgery
Moderate AS ?
Severe AS and Low Gradient
Small Left Ventricle
Normal EF but decreased SV
3
Normal Flow AS
ED
ES
Normal Flow AS
Paradoxical Low Flow AS
Pibarot & Dumesnil JACC 2009
ED
ES
Circulation. 2007;115:2856-2864
n = 381 SV > 35 cc
n = 181 SV < 35 cc
Low Gradient, Normal EF Severe AS
Management
Aggressive Rx of underlying disease
Intervention issues not resolved
Severe AS and Low Gradient
Filling dysfunction
Restrictive physiology
Low stroke volume
4
March 2009
•80 year old male, Active
•A Fib on Coumadin, Rate Control
•Soft A2, 4/6 SEM
•Active, No Symptoms
Case
March 2009 Mean Grad 10 mm Hg AVA 1.4 sqcm
May 2011
•80 year old male, Active
•A Fib on Coumadin, Rate Control
•Exertional Dyspnea
May 2011 EF 50% Maximum Grad 68 Mean Grad 35 mm Hg AVA 0.9 sqcm Elevated Filling Pressures Cath: 2V CAD
•Had AVR, CABG, Maze Procedure
•LA appendage pathology: Amyloidosis
•Heart Failure
•Prolonged hospitalization
•QOL worse than pre-op
Filling dysfunction
Restrictive physiology
Low stroke volume
Many causes
AS + Restrictive CMP
Management
Severe AS Surgery
Anticipate increased events
Severe AS and Low Gradient
Coexisting
Moderate or severe MR
5
Coexisting MR Coexisting MR
Coexisting MR
SV 46 ml Forward CO 2.6 l/min
AS + Co-existing MV disease
Management
Severe AS Surgery for Ao V and MV
Anticipate increased events
Severe AS but Low Gradient
Low EF Low Stroke
Volume Small LV
Normal EF Low SV
Normal EF Mod-Severe
MR
Normal EF Restrictive
Filling
Increased Vascular
Load
Low Gradient, Severe AS
Management
Surgery, TAVI
Case by case judgement
Thank you !