Role of the Echocardiogram in the
Assessment of Pulmonary Hypertension
and the Right Ventricle
Antoine Hage, M.D
Director, Solid Organ Transplant Cardiology
Co-Director, Pulmonary Hypertension Program
Cedars Sinai Heart Institute
Clinical Professor of Medicine/ Cardiology
David Geffen School of Medicine at UCLA
Role of Echocardiography
in Pulmonary Hypertension: Overview
•
Definition and classification
•
Role of ECHO in
– Diagnosis (allows identification of patients for whom RHC is
required)
– Screening high risk patient populations
– Evaluation of Structure/ Morphology/ Function/ Hemodynamics of
RV and PA (CHD)
– Determining etiology / PH group (PAH vs PVH) and secondary
causes
– Risk stratification (Evaluation of functional and hemodynamic
impairment)
– Formulating therapeutic options, monitoring disease stability and
response to therapy (longitutudinal F/U)
– Prognostic evaluation
2
Hemodynamic Definition of PH/PAH
PH
PAH
Mean PAP ≥25 mm Hg
Mean PAP ≥25 mm Hg plus
PCWP/LVEDP ≤15 mm Hg
ACCF/AHA CECD includes PVR >3 Wood Units
Badesch D et al. J Am Coll Cardiol. 2009;54:S55-S66.
McLaughlin VV et al. J Am Coll Cardiol. 2009;53:1573-1619.
1. PAH
•Idiopathic PAH
•Heritable (BMPR2, ALK1, Endoglin)
•Drug- and toxin-induced
•Persistent PH of newborn
•Associated with:
−CTD
−HIV infection
−portal hypertension
−CHD
−schistosomiasis
−chronic hemolytic anemia
3. PH Owing to Lung Diseases and/or Hypoxia
•COPD
•ILD
•Other pulmonary diseases with mixed
restrictive and obstructive pattern
•Sleep-disordered breathing
•Alveolar hypoventilation disorders
•Chronic exposure to high altitude
•Developmental abnormalities
4. CTEPH
1’. PVOD and/or PCH
5. PH With Unclear Multifactorial Mechanisms
2. PH Owing to Left Heart Diseases
•Systolic dysfunction
•Diastolic dysfunction
•Valvular disease
Simonneau G et al. J Am Coll Cardiol. 2009;54;S43-S54.
•Hematologic disorders (MPD, splenectomy,..)
•Systemic disorders (sarcoidosis, LAM,..)
•Metabolic disorders (e.g Thyroid disorders,.. )
•Others (e.g Renal failure/ dialysis,
fibrosingmediastinitis,..)
When to Suspect and Screen for PAH
•
•
•
•
•
•
•
•
Family history
– 6% - 12% prevalence of positive family history. If BMPR2 present, 20% chance of developing PAH.
– Autosomal dominant, incomplete penetrance, genetic anticipation
Connective tissue disease
– Limited and diffuse scleroderma: 8%- 30%
– CREST: up to 20% - 25%
– Systemic lupus erythematosus: 4% - 14%
– Rheumatoid arthritis up to 21%
Congenital Heart Disease
– Reversal of left-to-right shunt
– Ventricular septal defect, patent ductusarteriosus, atrialseptal defect
Portal hypertension
– Nearly 10% have elevated right ventricular systolic pressure by echo and RHC.
– 4% have severe PAH to contraindicate liver transplantation
Deep venous thrombosis/history of pulmonary embolism
– Up to 3-4% of survivors
Appetite suppressant or stimulant use
– 1/20000 of Fen Phen users more than 3 months
– Methamphetamine use
HIV
– 0.5% (1/200) patients.
Sickle cell disease, hemodialysis patients, etc
Echocardiography in Pulmonary HTN
 Echocardiography is an integral part of the assessment of a patient with PH,
Often the first test to detect PH
 Evaluates cardiac structure, function and hemodynamics
 Rules out congenital heart diseases and shunts*
 Provides a reasonably accurate estimate of pulmonary artery pressures
 Guides diagnosis and therapy
 Helps determine prognosis: Many Echo parameters are prognostic indicators:
•RV size and function (eg,TAPSE, S’, FAC, MPI/TEI index)
• Pericardial effusion
• Estimate of CO/CI and RA pressure (hemodynamics)
* May need TEE
6
Role of Echocardiography in
the Screening of Patients at
Risk of Developing PH/ PAH
When to Suspect and Screen for PAH
• Family history/ Heritable PAH
• Connective tissue disease
• Congenital Heart Disease
• Portal hypertension
• Deep venous thrombosis/ history of pulmonary embolism
• HIV patients
• Appetite suppressant or stimulant use (Methamphetamine)
• Sickle cell disease, hemodialysis patients/fistula, sarcoidosis,
post-splenectomy etc.
Echocardiographic Criteria
Corresponding to Various Levels of
Likelihood of Presence of Pulmonary
Hypertension
Peak tricuspid jet
velocity m/sec
Estimated sPAP mm
Hg
Other echo signs of
PH present*
PH ( grade of
evidence)
< 2.8
<36
No
Unlikely (I-B)
< 2.8
<36
Yes*
Possible (IIa- C)
2.9 - 3.4
37 - 50
No
Possible (IIa-C)#
> 3.4
> 50
Yes/No
Likely (I-B)
* Eg, if RV morphology and function and/or systolic time intervals such as PAAT, or mid systolic deceleration of right
ventricular ejection (notching) are suggestive of PH, such diagnosis should
be considered “possible” even if Doppler estimate of sPAP is within normal range .
# TRV > 2.8 m/Sec corresponds to TIPG > 31 mm Hg, suggest PH except in elderly
or very obese patients
Galie N, et al: EurRespir J. 2009; 34; 1219-1263
Screening Patient Groups at Risk of Developing PAH
•
Yearly echocardiography is recommended in patients
– At risk for heritable PAH
– With CTD, especially patients with scleroderma
• Some recommend echo Q 2 years if normal
BNP and :
– DLCO > 70% and
– FVC% /DLCO% < 1.6
–
•
With sickle cell disease
Echocardiography should be considered, in patients with PHsuggestive symptoms
–
–
–
–
–
–
After pulmonary embolism
With HIV infection
With portal hypertension
With prior appetite suppressant use
With sarcoidosis
After splenectomy
10
Limitations of Echocardiography in PAH
•
•
•
•
•
•
•
1,2
Experienced technicians and interpreting physicians are essential
Consistency of skilled technicians/readers
– Applies to all imaging modalities
Images can be limited in some patient populations
The RV, the chamber of highest concern in PAH, is the least
emphasized on the “standard” echocardiography exam
TR jet may be absent in some patients, thus precluding PASP
assessment
May overestimate or underestimate actual pulmonary arterial
pressure
Can estimate LVEDP (PCWP) or CO/CI, but may prove impractical
CI, cardiac index; CO, cardiac output; LVEDP, left ventricular end diastolic pressure; PASP, pulmonary arterial systolic
pressure; PCWP, pulmonary capillary wedge pressure; RV, right ventricle; TR, tricuspid regurgitation.
1. Cheitlin et al. Circulation. 1997;95:1686-1744.
2. McGoon et al. Chest. 2004;126:14S-34S.
11
ECHO FEATURES OF PULMONARY
ARTERIAL HYPERTENSION
ECHO FEATURES OF PULMONARY ARTERIAL HYPERTENSION
Right atrial enlargement
Right ventricular enlargement/dilatation - D-shaped LV on short axis
Right ventricular hypertrophy
Significant tricuspid regurgitation – (TR jet estimated RVSP is 4V2 + RAP)
Right ventricular dysfunction
Pulmonary regurgitation - PR jet estimated mPA and PAEDP
Reduced RV outflow tract velocity, short acceleration time
Dilated IVC not collapsing with respiration (if patient not ventilated)
Patent foramen ovale (bubble contrast used)
Pericardial effusion
Dilated pulmonary arteries
12
Echocardiographic Findings that Increase
Clinical Suspicion of PVH
•Absence of right heart chamber enlargement or pericardial effusion
• Evidence of left atrial enlargement
• Presence of left ventricular hypertrophy
• Impaired diastolic relaxation indices
• Elevated left ventricular filling pressures as determined by E/e’
ratio >15 (most reliable predictor of LA pressure >15 mmHg)
• Extent of functional MR and size of mitral valve regurgitant orifice
at rest or during exercise (predictor of increased PA and pulmonary
edema in ischemic heart disease and probably in HFpEF)
• Modest elevation of pulmonary pressures (i.e., 60’s rather than >
80’s)
13
Findings that Increase the Clinical Suspicion of PVH
• Age (elderly)
• Female gender
• Obesity
• Systemic Htn (particularly if not optimally controlled) and LVH
• Diabetes mellitus
• Coronary artery disease
• Obstructive sleep apnea
• Atrial fibrillation
Lack of right axis deviation
Lack of right atrial enlargement or RVH
Evidence of left atrial enlargement
Evidence of left ventricular hypertrophy
Pulmonary vascular congestion/ Kerley B lines
Pulmonary edema
Pleural effusion
14
Progression of RV Dysfunction in
PAH
Champion H C et al. Circulation 2009;120:992-1007
15
Role of Echo in Diagnosis of PH and
Assessment of PA / RV Hemodynamics
Estimating Pulmonary Artery Pressures
by Echo
TR
Mean
PR
TR TR
Diast
2*
SPAP
= 4TR Vmax2 + RAP
Diast PA
= 4PRend Vmax2 + RAP
Mean PA
= TR Vmean+ RAP
Or = 4PR Vmax2 + RAP
TR Vmax= Peak TR velocity
PRend Vmax= End PR velocity
PR Vmax= Peak PR velocity
TR Vmean=from VTI
Modified from Garvan Kane
Mean Pulmonary Artery pressure
• The most reproducible method to
estimate mean PA pressure is
based on the mean Doppler
gradient of the tricuspid
regurgitant (TR) signal
Mean PA
Pressure
Mean systolic
= RV-RA gradient
Aduen JF, et al. J Am Soc Echocardiogr. 2009: 22; 814-819
Estimated
RA+pressure
Pulmonary Artery Mean and
Diastolic Pressures
mPAP
= 79 – 0.45x (PAAT)
= 79 - 0.45x (130)
=79-59
= 20 mm Hg
PA Diastolic Pressure
• [PADP = 4 x (end-diastolic pulmonary
regurgitant velocity)² + RA pressure]
Mean PA Pressure
•mPAP = 1/3(SPAP) + 2/3(PADP)
• Or 4 x (early PR velocity)² + estimated RA pressure
•Or: 0.61 xsPAP + 2 mm Hg ( Chemla’s Equation)
•Or: 79 - 0.45 x (PAAT)
• Or: 90 – (0.62 x PAAT)
• Or mPAP= 80 – 0.5 x (PAAT)
•Or: RAP + VTI of TR jet
mPAP
=79 – 0.45x (PAAT)
=79- 0.45x (70)
= 79 – 32
= 47 mm Hg
CHEST. 2011;139(5):973-975.
Pulmonary Acceleration Time
PV AccT 72 ms
mPA = 47 mm Hg
Mean PA pressure = 79 - (0.45 x AT)
PA in Pulmonary vascular disease
CTEPH- Before PTE
Same pt After PTE
Right Atrial Pressure Estimate:
IVC and Hepatic Vein
Right atrial (RA) pressure estimate should not
not be based on an arbitrary value, but
rather based on 2D and Doppler imaging of
the IVC and hepatic veins*
Modified from Garvan Kane
*Hepatic veins > 11 mm is abnormal
Right Atrial Pressure Estimate:
IVC and Hepatic Vein
American Society of Echocardiography
Recommends:
• 3mmHg, IVC diameter <21mm w/
>50% collapse
• 8mmHg, IVC normal in diameter w/
<50% collapse
• 15mmHg, IVC diameter >21mm w/
>50% collapse
• 20mmHg, IVC dilatation with <50%
collapse
23
Right Atrial Pressure Estimate:
Hepatic Vein Flow in PAH Patients
•Systolic filling fraction: Vs/ (Vs + Vd) < 55% sensitive
and specific for increased RA pressure
• Abnormal: A wave is larger than systolic S wave
Abnormal
A
A
A
D
S
S
D
Normal: Systolic predominance in hep. vein flow
Abnormal: Vs/Vd< 1 (eg; High RA pressure)
D
How should you define mild, moderate,
and severe PH?
• Not by RVSP
• Not by the ratio of RVSP to systemic BP
• Define PH severity by
the degree of:
– RV dilatation
– RV dysfunction
– RA pressure elevation
– Decrease in cardiac index
Modified from Garvan Kane
Right Ventricular Afterload
RESISTANCE
PVR: mean PAP – PCWP = TPG
Flow (CO)
CO
 Reflects the arterial load to steady flow
 Doppler correlate:
Peak TR pressure gradient / RVOT TVI
(although does not incorporate LV filling pressure)
Modified from Garvan Kane
PVR
PVR = [(TRV/TVIRVOT) x 10] + 0.16 (Abbas Formula)*
= (3.9 / 10.2) x10 + 0.16; = 0.38 x10 + 0.16; = 3.8+ 0.16
= 3.98 WU
PVRc = (RVSP – E/e’) / VTIRVOT (Corrected Dahiya equation)#
*Abbas, AE et al. JACC 2003. 41: 1021-1027
#Dahiya, A et al . Heart 2010. 96: 2005-2009
PA – W Sign
Right Ventricular Afterload
Compliance / Capacitance

Can be estimated by SV / Pulse Pressure (by cath or ECHO)

May be as (more) important in PH as resistance

Pulsatile component of pressure and flow is 30-50% of power transferred from RV to
pulmonary bed

Less than 1.0 is abnormal and < 0.8 mL/mm Hg predicts mortality in PAH patients
PVCAP =
Stroke Volume
=
LVOT Area x TVI
PA Pulse Pressure*
4 (TR Vmax2 – PRendV2)
PVCAP = Pulmonary vascular capacitance
* PA systolic – PA diastolic
Mahapatra, S et al. J. Am Soc Echocardiogr, 2006, 19:
1045-1050
Indirect Echocardiographic Findings in PH
PV AccT 72 ms
= 47 mm Hg
Mean PA pressure :
= 79 - (0.45x PAAT)
• Or = 90 – (0.62 x PAAT)
• Or =80 – 0.5 x (PAAT)
• RVOT Acceleration time < 90 msec
•“Flying W” sign by M-Mode (mid-systolic
notching)
• Dilated Coronary Sinus
Reynolds, BS, RDCS, Terry. The Echocardiographer’s Pocket
Reference. Arizona: 2007. Print.
30
Echocardiographic Features of PAH
US/DS/MAR11/001
RV Apical 4 Chamber view:
Obtain apical long axis views optimized to visualize RV
RV centric
LV centric
RA / RV Morphology in PAH
RV Dilatation / LV Compression
RAE / IAS Displacement
Flattening / D-shaped Septum
Apex-forming RV
RV size: Qualitative “Eyeball” Estimate
Normal
Normal
Mild RVE
RV Similar to LV/ Shares apex
RV 2/3 size of LV
Moderate
RVE
RV Larger than LV
Severe
RVE
Very large RV/ Apex forming
D shaped septum
Quantitative Estimate of RV Size




Length (> 86 mm*)
Mid diameter (> 35 mm*)
Basal diameter (>42 mm*)
RV area > 28 cm2*
* Measures indicate dilatation
• RV end-diastolic diameter has been identified
as a predictor of survival in patients with
chronic pulmonary disease
Tips
• Measure at end diastole from an RV
focused apical 4-chamber view
• Optimize image to have maximum
diameter without foreshortening the
ventricle
Rudski,LG et al. J. Am Soc Echocardiogr 2010.23: 685-713
US/DS/MAR11/001
RVH: RV thickness > 0.5 cm
RV measurements in 2D
• RV end-diastolic
diameter has been
identified as a
predictor of survival
in patients with
chronic pulmonary
disease
• RV Enlargement:
RVD1 > 42 mm or
RVD2 > 35 mm or
RV Length > 79 mm
RV Area > 28 cm2
J Am Soc Echocardiogr 2010;23:685-713.
RVH: RV thickness > 0.5 cm
36
Septal Flattening- Eccentricity Index
D1
D2
Eccentricity Index : D1/D2 > 1
In Diastole= volume overload
In Systole= volume and pressure overload
E.I = 40/25 = 1.6 (D1/D2)
37
Pericardial Effusion: A bad Sign in PH
• Associated with greater
disease severity
• Increases mortality risk
• Likely reflects high venous
pressure and poor lymphatics
drainage rather than a risk of
cardiac tamponade
Echo and RV Function
• 3D ECHO might become gold standard
• No other valid quantitative assessment of RV function
–
–
–
–
–
–
–
–
Subjective evaluation
Tricuspid annular plane systolic excursion (TAPSE)
Tricuspid annulus TDI velocities (S’)
RIMP (Tei Index)
RV area fractional shortening
Dp/dt
RV longitudinal strain measurement
Measurement of cardiac output
Echo measures of RV Function: TAPSE
TAPSE
•
Simple, reproducible
•
Represents longitudinal function
•
Correlates well with radionuclide
angiography in determining RV systolic
function. Relatively load dependent.
•
Normal > 20 mm.
•
TAPSE < 18 mm has negative
prognostic implications
•
Angle and load dependent
To execute:
– In Apical-4 chamber view, place M-Mode
cursor through the lateral tricuspid
annulus
– Measure excursion from end-diastole to
end-systole
– Average over 3 beats
– Off-axis views tend to overestimate
TAPSE (as with the apex-forming RV)
J Am Soc Echocardiogr 2010;23:685-713., Heart
2006;92:i19-i26 doi:10.1136/hrt.2005.082503
40
Echo Measures of RV Function:
TV annular velocity (S’) by TDI
TV Annular velocity s’
• MPI=(TCO-ET)/ET
• Simple, sensitive, reproducible
• Good indicator of basal free wall function
• By TDI, several indices of RV function can be
obtained from a single cardiac cycle
Peak velocities
Isovolumic parameters
Tei index
• Angle dependant
• Relatively independent of loading conditions
• Correlated with RVEF by first pass
radionuclide ventriculography
•Normal > 10 cm/s
• Normal MPI by TDI < 0.55
The RV Index of Myocardial Performance (RIMP)
Global Indicator of Systolic and Diastolic Function.
• Needs the measurements
of 2 different cardiac cycles
(tricuspid inflow and RV
outflow by PW Doppler)
• Normal values below 0.4
(mean 0.28)
• Relatively independent of HR
and from loading conditions
• Prognostic in PH
• May get pseudonormalized
with high RVDP/ RAP
Haddad F et al. Circulation 2008;117:1436-1448
Tei C, et al: J Am Soc Echocardiogr. 1996; 9: 838-847
RV FAC (Fractional Area Change) / Apex-forming RV
RV FAC%= 100x RVarea diastole – RVareasystole / Rvareadiastole
27.2 - 21.7 / 27.2 = 20%
43
Dp/dt
Rate of rise of LV or RV pressure
Normal dp/dt> 400 mm Hg/sec
Role of ECHO in Therapy, Longitudinal
F/U and Prognosis
Prognostic Parameters and
Determinants of Risk in PAH
LOWER RISK
DETERMINANTS OF RISK
HIGHER RISK
No
Clinical evidence of RV failure
Yes
Gradual
Progression of symptoms
Rapid
II, III
WHO class
IV
Longer (>400 m)
6MWD
Shorter (<300 m)
Peak VO2>10.4 mL/kg/min
CPET
Peak VO2<10.4 mL/kg/min
Echocardiography
Pericardial effusion, significant
RV enlargement/dysfunction;
RA enlargement
Minimal RV dysfunction
(TAPSE in ESC guidelines)
RAP <10 mm Hg;
CI >2.5 L/min/m2
Hemodynamics
RAP >20 mm Hg;
CI <2.0 L/min/m2
Minimally elevated
BNP
Significantly elevated
Syncope is poor prognostic sign added in the ESC guidelines
McLaughlin VV et al. J Am CollCardiol. 2009;53:1573-1619.
46
Prognostic Value of Echo Parameters of RV Function
• 47 pts with PAH
•2-year survival = 88 % if TAPSE > 18 mm
•
2-year survival = 50 % if TAPSE < 18 mm
•Forfia PR – Am J RespirCrit Care Med 2006; 174: 103441
Prognostic Value of MPI
YeoTc – Am J Cardiol 1998; 81:1157-61
Tei, C- JASE 1996; 9: 838-47
Prognostic Value of MPI
Meluzin J – Eur J Echocardiogr 2003; 4: 267-71
Van Wolferen, SA et al. Eur Heart J (2007) 28, 1250–1257
Kaplan-Meier Survival Curves for
Echocardiographic Predictors of Outcomes
81 pts prostacyclinevs placebo
F/U 36 months, 20 deaths, 21 transplantations
Raymond, R. J. et al. J Am CollCardiol 2002;39:1214-1219
Right atrial area > 20 cm2, abnormal; > 27 cm2 associated with poor prognosis
Eccentricity index > 1 abnormal; > 1.7 carries poor prognosis
Suggested Assessments and Timing for
Follow-ups in patients with PAH: ESC
Guidelines
Role of Echo in Determination
of PH Group
Determining PH Type on Basis of ECHO
• Caution is needed in distinguishing PAH from PH
related to diastolic abnormalities solely on the basis of
ECHO
• Features of “diastolic dysfunction”, e.g., delayed
relaxation pattern and reduced e’ (mitral annular
tissue velocities), may occur in PAH ( secondary to bad
RV)
• Pulmonary vascular resistance (PVR) calculations by
ECHO do not take into account left atrial pressurethey do not distinguish PAH from PVH.
Left-sided vs. Right-sided Origin of Pulmonary Hypertension
Left-Sided Origin of PH
Right-Sided Origin of PH
2-D Echocardiographic Findings:
LVH, LAE
Variable LV function
Normal RV size
No interventricular septal bowing
Normal LV size, normal LA size
Normal LV function
RV dilation (ratio of RV:LV size >1)
Right to left interventricularseptal bowing
Atrial septum neutral or bowed to right
Atrial septum bowed to left
Normal or mildly reduced RV function
Mild to severe RV dysfunction
No pericardial effusion
Mild to moderate pericardial effusion
Doppler Findings:
≥2+ mitral valve disease (MR or MS)
Minimal or no MR or MS
Grade II or III diastolic dysfunction
Normal diastolic function or grade I diastolic
dysfunction (E:A reversal)
Variable TR
Absence of notched pattern in Doppler
signal obtained from RVOT
Variable TR (TR severity > MR severity)
Notched Doppler signal in RVOT
Variable PASP (typically <70 mm Hg)
Variable PASP (typically ≥70 mm Hg)
52
EchocardiographicParameters for the
Assessment of Pulmonary Hypertension/ Right
Ventricle
•
Size and surface areas of both atria.
•
Bi-ventricular size and systolic /diastolic function (RV), presence of RVH, CMY,
any valvular abnormality (MS, MR, AS etc..), pericardial effusion or
intracardiacshunt:
– Subjective “eyeball” assessment of RV function ( good vs mild, moderate or severe
RV dysfunction)
– Percent Fractional Area Change (% FAC)
– Tricuspid Annular Plane Systolic Excursion (TAPSE)
– Eccentricity Index / D-shaping of the IVS
– RV Myocardial Performance Index (MPI) or Tei index
– TDI systolic velocity of the RV lateral annulus (S’), (and short IVRT on RV TDI)
•
Pulmonary artery pressure estimation / Hemodynamics:
– Pulmonary Artery Acceleration Time (PAAT) and presence/ timing of Notching
– Pulmonary artery pressures (Systolic, Diastolic, Mean) , Resistance and Capacitance
•
RA pressure ( IVC size and collapse)
•
Assessment of C.O ( LVOTdiameter and time-velocity integral of aortic flow by PW
Doppler)
•
Bubble study (CHD, PFO)
•
3D echocardiography, myocardial deformation techniques (strain imaging or
Role of ECHO in PH: Summary
 ECHO is an essential tool and plays a key role the initial and
subsequent evaluation of a patient with PH. Despite its
limitations, it remains the most clinically useful nonivasive
test for the assessment of the pulmonary circulation
 ECHO Provides a reasonably accurate estimate of the RV /
PA pressures and hemodynamics .
 The prognostic value of the echocardiographic parameters
discussed here are well established, and the regular
assessment of these, as part of a goal-oriented therapy, is
critical to monitor the progression of PH and the response
of patients to PAH specific therapy, independent of clinical
and RHC data
Acknowledgements
Lauren Skinner, RDCS:
Preparation and acquisition of many of the slides
Sonographers RDCS:
•
•
•
•
Yvonne Golomb
Liliana (Lily) Miranda
Carol Mortier
Yousef Kohen
Partners
–
–
–
–
–
–
–
Jon Kobashigawa, M.D
Jaime Moriguchi, M.D
Michele Hamilton, M.D
Jignesh Patel, M.D
BabakAzarbal, M.D
Michelle Kittleson, M.D
David Chang, M.D
THANK YOU
Any questions?