Download Pulmonary Hypertension

Pulmonary
Hypertension
Christina T. Sheridan, MD
Pediatric cardiologist
October 16, 2014
Disclosures
I have no
financial
disclosures.
Neonatal Pulmonary HTN
• Incidence ~2/1000 term births
• Three main types
– Lung parenchymal diseases
– Idiopathic: normal parenchyma, but remodeled
vasculature
– Hypoplastic vasculature
• Symptoms: tachypnea, increase O2
requirement or vent settings, differential O2
sats in upper and lower limbs
Normal transition
• PVR falls rapidly immediately after birth due
to
– Mechanical stretch of lung as pulmonary blood
flow increases 10x
– Decreasing CO2 tension
– Increasing O2 tension
– Increase in local production of vasodilators (NOcGMP pathway)
To arms
To legs
Differential pre-post ductal sats
Etiologies
• Lung parenchymal diseases
– Infection
– MEC aspiration
– Respiratory distress syndrome
• Idiopathic
– Premature closure of the PDA due to maternal use of
NSAIDS or maternal use of SSRIs
– Can cause RV failure and hydrops in utero
• Hypoplastic vasculature
– Diaphragmatic hernia, chest masses, etc
Work-up
•
•
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•
CXR
Head US : rule out intraventricular bleed
Lab work: Infection? Polycythemia?
Echocardiogram:
– Rule out structural defects
– Assess pulmonary veins
– Assess direction of PDA and PFO shunts
– Quantify degree of PAp via septal curvature and
tricuspid regurgitation (TR) jet
Quantifying degree of TR
PISA refers to the degree
of color bleed of a
regurgitant jet.
The vena contracta is the
narrowest width of the TR
jet where the max velocity
is measured by Doppler
Image source: www.echobasics.de
TR jet by numbers
Pressure gradient = 4V2
(ex: V=3m/s; RVsp=36mmHg)
Image source: www.adhb.govt.nz
Definitions
• Normal PVR (pulmonary vascular resistance) is 1-3 Woods
units after about 2 months of age
• Normal SVR (systemic vascular resistance) is 15-30
Woods units
• Normal RVsp <25mmHg + RA pressure*
• Peds: RAp 2-5mmHg
• Adults: RAp 5-10mmHg
Septal curvature
Normal RV shape and LV
curvature.
Downloaded from Circulation: 1983;68:68-75
Bedside treatment
• Minimize handling, suctioning
• Maintain temp, nutritional support, electrolytes
balance
• Surfactant for preemies or with parenchymal lung
disease
• Antibiotics for infection
• Vasodilate with O2, but avoid oxidative stress or
barotrauma
• High frequency ventilation, ECMO
Nitric oxide: NO
• NO is made by endothelial cells and
causes vasodilation
• Mechanism of action: cyclic gMPdependent pathway, which also
inhibits platelet formation and
smooth muscle proliferation
• Must be given inhaled and
continuously
• Caution needed at end of wean in
case of rebound pulmonary HTN
Pediatr Crit Care Med. Mar 2010; 11(2 Suppl): S79–S84.
ECMO
Extra Corporeal Membranous Oxygenation
Etiology of pulmonary HTN in Adults
• Primary Pulmonary artery hypertension
– Due to HIV, connective tissue disorder, liver
disease, etc.
• Secondary pulmonary HTN: related to heart
disease, lung disease, blood clots in the lungs,
obstructive sleep apnea
• Idiopathic pulmonary HTN
Older children and adults
• Children with Down syndrome
• Unrepaired congenital heart defects with
increased pulmonary blood flow
– VSDs
– ASDs
– PDAs
– AP windows
– AV canals
– Truncus arteriosus, double outlet right ventricles
Symptoms
• Shortness of breath with exercise, that
progresses to activities of daily living
• Fatigue and dizziness
• Syncope
• Chest pain
• Peripheral edema due to right heart failure
and increased venous pressure
• Duskiness, polycythemia due to desaturation
Image source:www.nationwidechildrens.org
Case 1
4 year old boy with Down syndrome, moderate
sized perimembranous VSD
Moderately active, snores at night, frequent
URIs
Referred for VSD closures at LPCH
Indications for cardiac cath: Down syndrome
and age of patient. If PVR<7, can close VSD
Perimembranous VSD
Cardiac cath results
PVR was 7.6 on room air, sedated
Pulmonary artery pressures were systemic
Patient given 20ppm nitric oxide and O2 in
the cath lab  PVR dropped to 0.85
Qp:Qs was 2:2
VSD closure deferred
Other work-up
needed
• Sleep study and ENT consult
– Patient deemed a suitable candidate for a
tonsillectomy and adenoidectomy
• Chest CT to evaluate for pulmonary artery
branches
• Patient started on sildenifil three times daily with
plans to repeat cardiac cath in 3-6 months
Case 2
• 3 year girl with hypoplastic left heart
syndrome (mitral and aortic valve atresia)
• Followed closely by PMD, GI and myself since
her Stage 2 palliation (Glenn shunt)
• Awaiting goal of 15kg or if more fatigued or
cyanotic for her stage 3 palliation surgery
(Fontan)
Image source: umm.edu
Case 2 Cardiac Cath
• Pre-Fontan cardiac caths are routinely done
• Assesses Glenn pressures, venous anatomy
and allows to coiling of any decompressing
collaterals
• Patient had good RV function and minimal AV
valve regurgitation
HLHS
Glenn circulation (stage 2)
www.pediatriccardiacinquest.mb.ca
Fontan circulation (stage 3)
www.rch.org.au
Management
• Patient clinically asymptomatic, aside from
duskiness when crying
• Glenn pressures slightly elevated despite good RV
function and minimal AVVR
• End diastolic filling pressure of RV slightly high,
therefore causing pressure back up into lungs
• Treat pt with captopril and lasix x 6 months, then
repeat cardiac cath, prior to Fontan discussion
Case 3
• 39 year old woman was born and raised in
Mexico
• Told that she had a large PDA that needed
surgical closure in childhood
• Family refused, scared of risks, surgery, denial
Case 3 continued
• Here in the US, the lady had 2 successful
pregnancies, but came to cardiology due to
progressive shortness of breath
• She was seen in our Adult Congenital Heart
Disease (ACHD) clinic
• Echo done and patient managed in ACHD
clinic and by pulmonary HTN clinic
• Followed by serial 6 minute walk tests
Right ventricular hypertrophy
D-shaped septum
Adult TR jet calc
Evaluation of suspected pulmonary
HTN
•
•
•
•
•
Syncope with exercise
Loud S2
Prominent RV heave
CXR shows cardiomegaly
Desaturations or increase in ventilation
pressures needed
Echocardiography
•
•
•
•
Assess the size of the right heart
Assess the intraventricular septum curvature
Calculate the RVsp by TR jet
Visualize congenital defects, direction of
shunts
Exercise testing
Maximum exercise stress test for
suspected PAH are NOT
recommended due to risk of
syncope and sudden death
Instead, pts are followed serially
with 6-minute walk tests.
Treatment options
• Vasodilators:
– Epoprostanol (Flolan) via a continuous IV infusion via a
backpack
– Iloprost (Ventavist): nebulized every 3 hours
•
•
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•
•
•
•
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Endothelin receptor antagonists: Bosantan (Tracleer)
PDE-5: sildenifil
High dose calcium channel blockers
Anticoagulants
Diuretics
Oxygen
Surgery to create an ASD to decompress the right heart
Heart lung transplant
Prognosis
• Untreated PAH, 68% chance of survival after
one year
• After 5 years, 34% chance of survival
• PH and scleroderma: 2 year survival odds are
40%
• Pregnancy and pulmonary hypertension are
dangerous combinations
• Clotting disorders must be evaluated and
treated to prevent pulmonary emboli