Pulmonary Hypertension Diagnosis and Cardiac Shunt Determination

PULMONARY HYPERTENSION
AND CARDIAC SHUNT
DETERMINATION
DR. RAJESH DAS

PULMONARY HYPERTENSION
OVERVIEW
 Definitions
 Pathogenesis
 Classification
 Diagnosis

IMPORTANT DEFINITIONS
Pulmonary hypertension (PH)
 is a haemodynamic and pathophysiological condition
defined as an increase in mean pulmonary arterial
pressure (PAP) ≥25 mmHg at rest as assessed by right
heart catheterization.
 The definition of PH on exercise as a mean PAP .30
mmHg as assessed by RHC is not supported by
published data and healthy individuals can reachmuch
higher values.
European Heart Journal (2009) 30, 2493–2537

HAEMODYNAMIC DEFINITIONS OF PULMONARY
HYPERTENSION

THE EXACT PROCESS IS STILL UNKNOWN!!
MOLECULAR ABNORMALITIES IN PAH
 Prostacyclin
 vasodilator,
 inhibits platelet activation,
 antiproliferative properties,
Prostacyclin synthase is decreased in the pulmonary
arteries in PAH.
 Endothelin-1
 Potent vasoconstrictor and stimulates PASMC
proliferation.
Plasma levels of ET-1 are increased in PAH and
clearance is reduced.

 Nitric Oxide.
 Vasodilator,
 inhibitor of platelet activation
 Inhibition of vascular smooth-muscle cell proliferation.
Impaired production of NO is seen in PAH.
 Serotonin (5-HT)
 vasoconstrictor and promotes PASMC hypertrophy and
hyperplasia.
Allelic variation in serotonin transporter(SERT) present in
PAH.
 Vasoactive intestinal peptide (VIP)
 has a pharmacologic profile similar to prostacyclins.
Serum and lung tissue VIP levels are decreased in PAH
patients

GENETICS OF PAH
 Bone Morphogenetic Protein Receptor 2
Gene(BMPR2)
 belong to the TGF-b superfamily involved in the control of
vascular cell proliferation.
 mutations are detected in at least 75% of cases PAH
occurs in a familial context.
 Mutations of this gene can also be detected in 25% of
apparently sporadic cases.
 Activin Receptor-like Kinase 1 And Endoglin
 PAH associated with HHT.

PATHOGENESIS OF PAH
Gaine S. J Am Med Assoc 2000;284:3160-68

CLASSIFICATION OF PULMONARY
HYPERTENSION
 First attempt in 1973 meeting organized by the
WHO.
 A distinction was made between primary and
secondary PH
 The Dana Point 2008 4th World Symposium on
PH
 Based on shared pathologic, pathobiologic, and
clinical features.

UPDATED CLINICAL CLASSIFICATION OF
PULMONARY ARTERIAL HYPERTENSION
(DANA POINT, 2008)
1 Pulmonary arterial
hypertension (PAH)
1.1 Idiopathic
1.2 Heritable
 1.2.1 BMPR2
 1.2.2 ALK1, endoglin
(with or without
hereditary haemorrhagic
telangiectasia)
 1.2.3 Unknown
1.3 Drugs and toxins induced
1.4 Associated with (APAH)
 1.4.1 Connective tissue diseases
 1.4.2 HIV infection
 1.4.3 Portal hypertension
 1.4.4 Congenital heart disease
 1.4.5 Schistosomiasis
 1.4.6 Chronic haemolytic anaemia
1.5 Persistent pulmonary hypertension of the
newborn
1’ Pulmonary veno-occlusive disease
and/or pulmonary capillary
haemangiomatosis
J Am Coll Cardiol 2009;54:S43–S54.

UPDATED CLINICAL CLASSIFICATION OF PULMONARY
ARTERIAL HYPERTENSION (DANA POINT, 2008)
2. Pulmonary hypertension
due to left heart disease
2.1. Systolic dysfunction
2.2. Diastolic dysfunction
2.3. Valvular disease
3. Pulmonary hypertension
due to lung diseases and/or
hypoxia
3.1. Chronic obstructive pulmonary
disease
3.2. Interstitial lung disease
3.3. Other pulmonary diseases
with mixed restrictive and
obstructive pattern
3.4. Sleep-disordered breathing
3.5. Alveolar hypoventilation
disorders
3.6. Chronic exposure to high
altitude
3.7. Developmental abnormalities

UPDATED CLINICAL CLASSIFICATION OF PULMONARY
ARTERIAL HYPERTENSION (DANA POINT, 2008)
4. Chronic thromboembolic pulmonary hypertension
(CTEPH)
5. PH with unclear multifactorial mechanisms
5.1. Hematologic disorders: myeloproliferative disorders
splenectomy.
5.2. Systemic disorders, sarcoidosis, pulmonary Langerhans
cell
histiocytosis, lymphangioleiomyomatosis, neurofibromatosis, vas
culitis
5.3. Metabolic disorders: glycogen storage disease, Gaucher
disease, thyroid disorders
5.4. Others: tumoral obstruction, fibrosing mediastinitis, chronic
renal failure on dialysis

EPEDIOMOLOGY
 Commonest cause of PH in adults is COPD.
 Estimated incidence of IPAH is 1-2 newly diagnosed
cases per million people per year.
 Prevalence of PAH in adult CHD- 5–10%, out of which
25- 50% presenting with ES.
Rev Esp Cardiol. 2010 Oct;63(10):1179-93

PH WITH CARDIAC SHUNT
 PAH associated with CHD is included in group 1 of the
PH clinical classification.
 Persistent exposure of the pulmonary vasculature to
increased blood flow may result in a typical pulmonary
obstructive arteriopathy (identical to other PAH forms)
that leads to the increase of PVR.
Rev Esp Cardiol. 2010 Oct;63(10):1179-93

CLINICAL CLASSIFICATION OF CONGENITAL SYSTEMIC-TO-
PULMONARY SHUNTS ASSOCIATED WITH PAH
A. Eisenmenger’s syndrome
 ES includes all systemic-to-pulmonary shunts due to large
defects leading to a severe increase in PVR and resulting in
a reversed or bidirectional shunt.
 Cyanosis, erythrocytosis, and multiple organ involvement are
present.
B. PAH associated with systemic-to-pulmonary shunts
 In these patients with moderate to large defects, the
increase in PVR is mild to moderate, systemic-to-pulmonary
shunt is still largely present.
 no cyanosis is present at rest.

C. PAH with small defects
 usually VSD<1 cm and ASD<2 cm of effective diameter
assessed by echocardiography.
 clinical picture similar to idiopathic PAH.
D. PAH after corrective cardiac surgery
 PAH is either still present immediately after surgery or has
recurred several months or years after surgery in the
absence of significant post-operative residual congenital
lesions.
CLINICAL CLASSIFICATION OF CONGENITAL SYSTEMIC-TO-
PULMONARY SHUNTS ASSOCIATED WITH PAH

WHEN SHOULD THE DIAGNOSIS OF
PAH BE CONSIDERED?
 Patients with unexplained exercise limitation
 Patients with clinical signs consistent with right
heart dysfunction
 Patients with abnormal right ventricular findings
on radiography, echocardiography or
electrocardiography
 Patients with systemic disease known to be
associated with PAH

SYMPTOMS ASSOCIATED WITH PAH
 Shortness of breath
 Syncope
 Chest pain
 Symptoms of RH dysfunction
Breathlessness
Ascites
Ankle swelling
Anorexia

SIGNS ASSOCIATED WITH PAH
 Loud split P2
 RV hypertrophy
 Increased “a” waves
 Increased “v” waves
 Diastolic murmur (PR)
 Pansystolic murmur (TR)

SIGNS OF RH FAILURE
 Poor peripheral perfusion
 Raised RA pressure
 RV 3rd and 4th heart sounds
 Tricuspid regurgitation
 Ejection systolic murmur across the pulmonary
valve

WHO CLASSIFICATION OF FUNCTIONAL
STATUS OF PATIENTS WITH PH

DIAGNOSIS OF PH WITH CARDIAC SHUNTS
 The signs and symptoms of Eisenmenger’s syndrome
result from PH, low arterial O2 saturation, and secondary
erythrocytosis.
 They include dyspnoea, fatigue, and syncope.
 haemoptysis, cerebrovascular accidents, brain
abscesses, coagulation abnormalities, and sudden death.

PULMONARY ARTERIAL HYPERTENSION: CLINICAL
COURSE AND PROGRESSION
CLEVELAND CLINIC JOURNAL OF MEDICINE 2007. 74(10)

DIAGNOSTIC ALGORITHM FOR PAH
Contd on next slide

DIAGNOSTIC ALGORITHM FOR PAH
CONTD..

FINDINGS ON ELECTROCARDIOGRAM
• Highly specific but not very sensitive.
• RVH, RAE, RAD, RBBB.

FINDINGS IN PH CHEST RADIOGRAPHY
 Cardiac enlargement
 Prominent proximal
PA
 “Pruning” of distal PA

ECHOCARDIOGRAPHY IN PAH
 T R
 RVE
 RAE
 RVH
 Flattening of IVS
 Dilated IVC

VENTILATION PERFUSION LUNG SCAN
IPAH CTEPH

CT FEATURES OF PULMONARY HYPERTENSION
 Wall-adherent thrombotic material in pulmonary
arteries
 CTEPH
 Severe idiopathic pulmonary arterial hypertension
 Calcifications in pulmonary arteries
 CTEPH
 Longstanding severe pulmonary hypertension
 Eisenmenger syndrome
 Peripheral pulmonary arteriovenous shunting
 Portopulmonary hypertension
 Hepatopulmonary syndrome
 Pulmonary vascular dilatation (central or peripheral)
 Left-to-right shunt
RadioGraphics 2010; 30:1753–1777

MAGNETIC RESONANCE IMAGING (MRI)
 Useful for Assessment of congenital heart diseases in children
and adults:
 visceral-atrial situs,
 connection and course of great veins and arteries,
 Hidden septal defects (sinus venosus ASD and
supracristal, or posterior ventricular septal defects)
 above all, assessment of the size and function of the cardiac
chambers, and in particular the right ventricle
Rev Esp Cardiol. 2007;60(9):895-8

GENETIC TESTING
Genetic testing and professional genetic counseling should
be offered to relatives of patients with FPAH.
CHEST 2007; 131:1917–1928

6 MINUTE WALK TESTING
In patients with PAH, serial determinations of functional class
and exercise capacity assessed by the 6 minute walk test
provide benchmarks for disease severity, response to
therapy, and progression.
CHEST 2007; 131:1917–1928

TRANSESOPHAGEAL ECHOCARDIOGRAPHY (TEE)
 Useful in detection of intracardiac shunts, especially
ASD and detect central pulmonary emboli
CHEST 2007; 131:1917–1928

PULMONARY ANGIOGRAPHY
 In patients with PAH and a V/Q scan suggestive of
CTEPH, pulmonary angiogram is required for
accurate diagnosis and best anatomic definition to
assess operability.
CHEST 2007; 131:1917–1928

RIGHT HEART CATHETERIZATION
 -CONFIRMATION OF DIAGNOSIS
 -EXCLUSION OF OTHER CAUSES
 -ESTABLISH SEVERITY
 -ASSEMENT OF PROGNOSIS
 -ASSESMENT OF PULMONARY VASOREACTIVITY:
 challenge with inhaled NO, intravenous epoprostenol or
intravenous adenosine.
 Positive Response:
 >10mm mean PAP decrease and
 < 30mmHg final mean PAP
 > 33% decrease in PVR, ideally to < 6 units.
 Unchanged or increased CI
CHEST 2007; 131:1917–1928

INTRACARDIAC SHUNTS
Left-to-right shunt
Right-to-left shunt
Bidirectional shunt

WHEN TO SUSPECT DURING
CATHETERIZATION?
 unexplained pulmonary artery oxygen saturation
exceeding 80%(? Left-Right shunt)
 unexplained arterial desaturation <95% (Right- left
shunt)
 Arterial desaturation commonly results from
alveolar hypoventilation and associated
physiological shunting
 oversedation from premedication,
 pulmonary disease,
 pulmonary venous congestion,
 pulmonary edema,
 cardiogenic shock.

METHODS TO ESTIMATE SHUNTS
Cardiac Catheterisation
 Oximeric method
 Indicator dilution method
Echocardiography

PRINCIPLES OF THE OXYMETRIC METHOD
 Blood Sampling from various chambers to
determine Oxygen Saturation.
 Left to Right Shunt is present when a
significant increase in blood oxygen
saturation is found between 2 right sided
vessels or chambers.

OXIMETRIC METHOD
 A “screening” oxygen saturation
measurement is done by sampling of blood
in the SVC and the pulmonary artery.
 If the difference is 8% or more, a left-to-right
shunt may be present, and an oximetry
“run” is performed.

OXIMETRIC RUN
Obtain a 2-ml sample
from each of the
following locations:
1. Left and or right PA.
2. Main PA.
3. RVOT.
4. RV-mid
5. RV-tricuspid valve or apex
6. RA- low or near tricuspid
valve
7. RA- mid
8.RA- high
9. SVC- low (near junction
with right atrium)
10. SVC- high (near junction
with innominate vein)
11. IVC- high (just at or below
diaphragm)
12. IVC- low L4-L5)
13. LV
14. Aorta(distal to insertion of
ductus )

OXIMETRIC RUN
For localizing Right to Left Shunts one should also
obtain samples from….
 Pulmonary Vein
 Left Atrium
 Left Ventricle
 Distal Aorta

OXIMETRY RUN
 A significant step-up is defined as an increase in blood
oxygen content or saturation that exceeds the normal
variability that might be observed if multiple samples
were drawn from that cardiac chamber.
 O2 content (ml/L)=
SpO2 × 1.36 (ml/g) × Hb (g/dL) × 10
 1 vol% = 1ml O2/100ml blood or 10 ml O2/L

OXIMETRY RUN
Dexter Criteria: significant step-up in oximetry run :
 Right Atrium: Highest O2 content in blood samples
drawn from the RA exceeds the highest content in the
venae cavae by 2 vol % .
 Right ventricle: If the highest RV sample is 1 vol %
higher than the highest RA sample.
 Pulm. artery: the PA oxygen content is more than 0.5
vol% greater than the highest RV sample.

OXIMETRY RUN

a Difference distal- proximal chamber.

FICK EQUATION
 The principles used to
determine Fick cardiac
output are also used to
quantify intra-cardiac
shunts.
 Flow= Oxygen
consumption/Arterial-
Venous oxygen content
difference.
 O2 consumption is
assumed based on
patient’s age, gender
and body surface area
when not directly
measured.

CALCULATION OF PULMONARY BLOOD FLOW
(QP)

CALCULATION OF SYSTEMIC BLOOD
FLOW (QS)

WHAT IS MIXED VENOUS O2 CONTENT?
 The MVO2 (mixed venous oxygen content) is the
average oxygen content of the blood in the
chamber proximal to the shunt.
 When assessing a left-to-right shunt at the level of
the RA, mixed venous oxygen content is calculated
by the Flamm formula:
 MVO2 = 3(SVC O2 content) + (IVC O2 content)
4

CALCULATION OF BIDIRECTIONAL SHUNTS
 Effective blood flow: the flow that would exist in
the absence of any left-to-right or right-to-left
shunting:

 L → R shunt = PBF – SBF (Or Qp – Qs)
Bidirectional shunts:
 L → R shunt = PBF – EBF (or Qp – QEP)
 R → L shunt = SBF – EBF (or Qs – QEP)
SHUNT CALCULATION

CLINICAL SIGNIFICANCE OF SHUNT


INDICATOR DILUTION METHOD
 More sensitive than the oximetric method in detection of
small shunts.
 Cannot be used to localize the level of a left-to-right
shunt.
 Dye used- Indocyanine Green.
 Left to Right : Dye is injected into pulmonary artery and
a sample is taken from the systemic artery.
 Right to Left: dye injected just proximal to the presumed
shunt and blood sample is taken from systemic artery

SHUNT ESTIMATION BY ECHOCARDIOGRAPHY
 PW Doppler or color flow imaging:
 flow disturbance is found downstream from the defect.
 velocity of blood flow through the shunt orifice is
related to the pressure gradient
 2D imaging;
 ASD-Dilation RA and RV,paradoxical septal motion .
 PDA & VSD: Dilation LA and LV.

IMPORTANCE OF PULMONARY VASCULAR
RESISTANCE CONGENITAL CENTRAL
SHUNTS
 The decision as to whether a patient with congenital
heart disease would profit from corrective surgery
often hinges on the calculated pulmonary vascular
resistance.
 IMPORTANT CALCULATIONS:
 PVR
 PVR:SVR ratio.

PULMONARY VASCULAR RESISTANCE
 PVR = mean PAP – mean LAP (or PCWP)
Qp
-in Woods Unit (mmHg/L/min)
 SVR = mean systemic arterial P – mean RAP
Qs
 PVRI= PVR/ BSA (Sq. m.)

FAVOURABLE OUTCOME IN SURGERY
 A baseline PVRI <6 Woods units/m2 associated
with a resistance ratio of <0.3 without a
vasoreactivity test is interpreted as indicative of a
favorable outcome following operations resulting in
a biventricular circulation.

FAVORABLE OUTCOME IN SURGERY
Acute vasodilator challenge using oxygen/ nitric
oxide:
 Done if baseline PVRI is between 6 and 9 Wood
units/m2 in the presence of a resistance ratio from
around 0.3-0.5.
 favorable outcome:
 A decrease of 20% in the PVRI.
 A decrease of around 20% in the ratio of pulmonary to
systemic vascular resistance
 A final PVR index of <6 Woods units/m2.
 A final ratio of resistance of <0.3.

Pulmonary Hypertension Diagnosis and Cardiac Shunt Determination

Recomendados

Recomendados

Mais conteúdo relacionado

Mais procurados

Mais procurados (20)

Destaque

Destaque (20)

Semelhante a Pulmonary Hypertension Diagnosis and Cardiac Shunt Determination

Semelhante a Pulmonary Hypertension Diagnosis and Cardiac Shunt Determination (20)

Último

Último (20)

Pulmonary Hypertension Diagnosis and Cardiac Shunt Determination