Pulmonary Hypertension

Pulmonary Physiology

main+distal pulmonary arteries→thin walled→dilation/contraction/collapse
-allow for varying amounts of blood delivery from right side of heart

low pressure system
-blood from RV→lungs
-blood doesn’t have to travel far

Pulmonary Pressure

pressure that right side of heart is pumping against

directly correlated to pulmonary vascular resistance
-increased pulmonary vascular resistance=increased pulmonary artery pressure
-causes RV to increase systolic pressure→preserves CO

constant elevated pulmonary pressure→pulmonary artery damage→thickened vascular walls→decreased gas exchange

Pulmonary Hypertension Pathophysiology (General)

constant elevated pulmonary pressure→strain to right side of heart→damage to right side of heart→right ventricle muscles thicken (cor pulmonale)→can’t pump blood→backflow to right atrium→backflow to superior+inferior vena cava→systemic edema→HF

Pulmonary Hypertension Classification

split into groups by world health organization (WHO)

1. pulmonary arterial hypertension (PAH)

2. pulmonary hypertension due to left heart disease (LHD)

3. pulmonary hypertension due to chronic lung disease and/or hypoxemia

4. pulmonary hypertension due to chronic thrombotic and/or embolic disease

5. pulmonary hypertension due to unclear multifactorial mechanisms

Group 1: Pulmonary Arterial Hypertension

PP: vasoconstriction
vascular proliferation
thrombosis
inflammation
abnormalities of molecular pathways
pulmonary vascular endothelial+smooth muscle cell-regulating genes

RF: 30-60 y/o
women
asbestos
silica
schistosomiasis
genetics
illegal drugs
smoking
liver dx
CKD
thromboembolic dx

E:
inherited:
BMPR2
ALK2

acquired
HIV
portal HTN
shistomiasis

mx:
amphetamine
cocaine
st john’s wort
phentermine
interferon

CM: early→asx
m/c→exertional dyspnea
decreased exercise tolerance
fatigue
angina
syncope/near-syncope
peripheral cyanosis
COPD sx
HF sx

PE: lower extremity edema
abdominal distention
palpation→right ventricular heave

heart sounds
loud pw sound
tricuspid regurgitation murmur

DX: NYHA classification system
1st line→echo
cardiopulmonary exercise test (CPET)
6 minute walk test
right heart catheter (RHC)→gold standard
r/o secondary causes→labs
pulmonary fxn tests
nocturnal oximetry
diffusing capacity of lungs for carbon monoxide (DLCO)
arterial blood gas (ABG)
CXR
chest CT
V/Q
EKG

TX:
NP:
pulmonary HTN center referral
cure→lung transplant

MX:
1st line+positive vasodilator challenge: CCB
bosetan

endothelin receptor antagonists
ambrisentan
macitentan

phosphodiesterase type 5 inhibitors
sidenafil
tadalafil

Group 2: Left Heart Disease (LHD)

PP: LHD→chronically elevated left arterial pressure→LV fail→backs up venous pressure→increased pulmonary pressure→increased pulmonary vascular smooth muscle+structural remodeling

RF: 30-60 y/o
women
asbestos
silica
schistosomiasis
genetics
illegal drugs
smoking
liver dx
CKD
thromboembolic dx

E: left ventricular systolic/diastolic dysfunction
mitral valve dx
aortic valve dx

CM: early→asx
m/c→exertional dyspnea
decreased exercise tolerance
fatigue
angina
syncope/near-syncope
peripheral cyanosis
COPD sx
HF sx

PE: lower extremity edema
abdominal distention
palpation→right ventricular heave

heart sounds
loud pw sound
tricuspid regurgitation murmur

DX: NYHA classification system
1st line→echo
cardiopulmonary exercise test (CPET)
6 minute walk test
right heart catheter (RHC)→gold standard
r/o secondary causes→labs
pulmonary fxn tests
nocturnal oximetry
diffusing capacity of lungs for carbon monoxide (DLCO)
arterial blood gas (ABG)
CXR
chest CT
V/Q
EKG

TX: pulmonary HTN center referral
cure→lung transplant

MX: tx HF+volume overload→decrease pulmonary venous pressure

Group 3: Pulmonary Hypertension due to Chronic Lung Disease and/or Hypoxemia

PP: parenchymal lung dx→alveolar hypoxemia→pulmonary vasoconstriction+pulmonary vascular remodeling+medial wall thickening of arterioles→destruction of small-medium sized vessels

RF: 30-60 y/o
women
asbestos
silica
schistosomiasis
genetics
illegal drugs
smoking
liver dx
CKD
thromboembolic dx

E: COPD
ILD
pulmonary fibrosis
obstructive sleep apnea (OSA)
high altitude
severe hypoxemia

CM: early→asx
m/c→exertional dyspnea
decreased exercise tolerance
fatigue
angina
syncope/near-syncope
peripheral cyanosis
COPD sx
HF sx

PE: lower extremity edema
abdominal distention
palpation→right ventricular heave

heart sounds
loud pw sound
tricuspid regurgitation murmur

DX: NYHA classification system
1st line→echo
cardiopulmonary exercise test (CPET)
6 minute walk test
right heart catheter (RHC)→gold standard
r/o secondary causes→labs
pulmonary fxn tests
nocturnal oximetry
diffusing capacity of lungs for carbon monoxide (DLCO)
arterial blood gas (ABG)
CXR
chest CT
V/Q
EKG

TX:
NP:
pulmonary HTN center referral
cure→lung transplant

MX: COPD/hypoxemia→supplemental O2 15+ hrs x daily

Group 4: Pulmonary Hypertension due to Chronic Thrombotic and/or Embolic Disease

PP: chronic pulmonary thromboembolic events→intraluminal thrombus→classic arteriopathy of small arteries+arterioles distal to partially/fully occluded vessel→increased pulmonary vascular resistance (PVR)

RF: 30-60 y/o
women
asbestos
silica
schistosomiasis
genetics
illegal drugs
smoking
liver dx
CKD
thromboembolic dx

E: PE
incomplete thromboembolic resolution
other clotting dxs

CM: early→asx
m/c→exertional dyspnea
decreased exercise tolerance
fatigue
angina
syncope/near-syncope
peripheral cyanosis
COPD sx
HF sx

PE: lower extremity edema
abdominal distention
palpation→right ventricular heave

heart sounds
loud pw sound
tricuspid regurgitation murmur

DX: NYHA classification system
1st line→echo
cardiopulmonary exercise test (CPET)
6 minute walk test
right heart catheter (RHC)→gold standard
r/o secondary causes→labs
pulmonary fxn tests
nocturnal oximetry
diffusing capacity of lungs for carbon monoxide (DLCO)
arterial blood gas (ABG)
CXR
chest CT
V/Q
EKG

TX:
NP:
pulmonary HTN center referral
cure→lung transplant
long-term anticoagulation
thromboendarterectomy

MX:
prostacyclins
epoprostenol
treprostinil
iloprost

Group 5: Pulmonary Hypertensions due to Unclear Multifactorial Mechanisms

PP: unknown

RF: 30-60 y/o
women
asbestos
silica
schistosomiasis
genetics
illegal drugs
smoking
liver dx
CKD
thromboembolic dx

E: miscellaneous casuses
PV
essential thrombocythemia
myloproliferative dxs
sarcoidosis
vasculitis
pulmonary vascular compression (ex: tumors)

CM: early→asx
m/c→exertional dyspnea
decreased exercise tolerance
fatigue
angina
syncope/near-syncope
peripheral cyanosis
COPD sx
HF sx

PE: lower extremity edema
abdominal distention
palpation→right ventricular heave

heart sounds
loud pw sound
tricuspid regurgitation murmur

DX: NYHA classification system
1st line→echo
cardiopulmonary exercise test (CPET)
6 minute walk test
right heart catheter (RHC)→gold standard
r/o secondary causes→labs
pulmonary fxn tests
nocturnal oximetry
diffusing capacity of lungs for carbon monoxide (DLCO)
arterial blood gas (ABG)
CXR
chest CT
V/Q
EKG

TX:
NP:
pulmonary HTN center referral
cure→lung transplant

MX: tx underlying dx

NYHA Classification System

class 1
pulmonary HTN+no physical activity limitation
no sx with physical activity

class 2
pulmonary HTN+slight physical activity limitation
rest→normal

physical activity (normal):
-undue dyspnea
-fatigue
-angina
-near syncope

class 3
pulmonary HTN+physical activity limitation
rest→normal

physical activity (light)
-undue dyspnea
-fatigue
-angina
-near syncope

class 5
pulmonary HTN+severe physical activity limitation
rest→dyspnea+fatigue

physical activity (any)
-undue dyspnea
-fatigue
-angina
-near syncope

Echo (ECG)

1st line dx

presumptive dx

measures right atrial (RA) and right ventricular (RV) size and fxn

estimates pulmonary artery systolic pressure (PASP)
-detected incidentally
-warrants further investigation

may reveal other common conditions associated with pulmonary HTN

Cardiopulmonary Exercise Test (CPET)

pt needs reasonable functional capacity

helps identify physical limitation

differentiates cardiac vs pulmonary causes

6 Minute Walk Test

determines baseline functional class of pt

evaluates degree of exertional hypoxemia+limitation

monitors progression+response to therapy

accurately predicts survival in PAH

Right Heart Catheterization (RHC) (Swan-Ganz vs Vasodilator Challenge)

gold standard dx→confirms dx

swan-ganz
-measures pulmonary artery wedge pressure (PAWP/PCWP)
-aids in assessment of pulmonary vasoreactivity

vasodilator challenge
-assesses ability of pulmonary arteries to relax with mx (no rxn→advanced dx)

R/O Other Dxs

labs
-ANA
-HIV
-LFT

pulmonary fxn tests
-nocturnal oximetry

diffusing capacity of the lungs for carbon monoxide (DLCO)

arterial blood gas (ABG)

CXR

high-resolution computed tomography (HRCT)

v/q scan

EKG

Pulmonary Hypertension Prognosis

delayed dx x up to 2 yrs

utxd→high mortality rate

IPAH prognosis→poor

previous tx median survival rate→2-3 yrs

secondary PH→depends on underlying dx+tx response

m/c death→decompensated RHF