Pulmonary Artery Hypertension (PAH) Flashcards
(43 cards)
**What symptoms should bring PAH into your differential?
Insidious onset, gradually progressive shortness of breath without wheezing.
**What are two important things you are likely to notice when doing the chest exam of someone with PAH?
Right side Parasternal heave with loud P2 on exam
Pulmonary valve is slamming shut causing the enhanced P2 sound. Often the S2 sounds become widely split because the right heart must squeeze for longer to get all of the blood out
**What findings do you expect to see in someone with pulmonary artery hypertension (PAH)?
Essentially normal in idiopathic PAH (group 1)
**What findings do you expect to see in the pulmonary function test of someone with PAH?
PULMONARY VASCULAR DISEASE PATTERN:
**What is the screening test of choice for PAH?
• what can you detect with this test?
Echocardiography
1 - Look to see if there is Right Ventricular Hypertrophy/ Septal Deviation
2 - Estimate Right Ventricular Pressure:
RVSP = 4V^2 + RA pressure (estimated by ultrasound)
RVSP is a good estimation of pulmonary ARTERY hypertension because SYSTOLIC RV pressure should only be slightly greater than PULMONARY ARTERY pressure
**After screening for PAH with echocardiography, what should you do?
• why do you need this test?
• what values confirm suspicion of PAH?
Confirmatory test with Right Heart Catheterization
Right Heart Catheter measures the PULMONARY CAPILLARY WEDGE PRESSURE (PCWP) - this is an estimate of the pressure in the LEFT VENTRICLE
***IF left ventricular pressures are NORMAL (aka less than 15 mmHg) then you can assume the pressure is not due to backup of pulmonary venous circulation into pulmonary arteries.
**What are the criteria that need to be met to diagnose PAH?
PA Hypertension:
MPAP (mean pulmonary arterial pressure) over 25 mmHg
PCWP (pulmonary capillary wedge pressure) less than 15 mmHg
**What is the visibly activity agent of choice for PAH?
Nitric Oxide
**If patient with PAH continues to worsen after treatment what do you do?
Refer them for a lung transplantation
What are the 2 general types of pulmonary hypertension?
•how do they differ?
Pulmonary HTN:
• Primary - no demonstrable cause
• Secondary - etiologic agent/mechanism can be defined
What are some causes of secondary pulmonary HTN?
Secondary PAH: • Parenchymal lung disease (and damage e.g. bleomycin) •Chronic Thromboemboli • Left-sided valvular disease • Myocardial disease • Congenital heart disease • Systemic connective tissue disease
note: remember any type of connective tissue disease or damage to the pulmonary parenchyma may result in vascular damage that reduces the cross-sectional area of the pulmonary capillary bed leading to HTN.
note: remember any type of connective tissue disease or damage to the pulmonary parenchyma may result in vascular damage that reduces the cross-sectional area of the pulmonary capillary bed leading to HTN.
Pulmonary artery hypertension is caused by increased vasoconstrictors and decreased vasodilators. Name 6 vasoconstrictors that are commonly up regulated?
- Endothelin - 1 (most potent)
- TXA-2 (constricts and causes platelet aggregation)
- Serotonin (found in dense granules of platelets)
- VEGF
- CNS stimulants like COCAINE
- Anorexiants
What are the 2 vasodilators whose down regulation may contribute to the development of PAH?
- NO
2. Prostacyclin (PGI2)
What symptom may be a tip off that someone has a connective tissue disorder underlying their pulmonary artery HTN?
Raynaud’s - this is seen in patients with Scleroderma (most common CT disorder leading to PAH), SLD, Rheumatoid arthritis
What are 5 non-connective tissue diseases that can cause PAH?
- HIV
- HHV-8
- Sickle Cell (10% of pts.)
- Portal HTN
- Thrombocytosis
- HHT
Why do sickle cell patients and people with hemoglobinopathies get PAH?
FREE HEME AND IRON ACTS AS A SCAVENGER OF NO.
**What is primary cause of pulmonary HTN?
• is this heritable? If so, how?
BMPR2 (bone morphogenic protein receptor 2) is found on Chromosome 2.
• 6-10% of the population has this and it is AUTOSOMAL DOMINANT INHERITANCE with REDUCED penetrance
note: asymptomatic carriers may have abnormal response during excercise
What diet pills are associated with causing PAH?
Fenfluramine/phentermine
What is the significance of many PAH patients showing negligible NOS enzyme? Where is this enzyme found?
• what is the function of NO?
NO synthase in the Vascular Endothelium:
• makes NO
NO functions to:
• Promote Vasodilation
• Inhibit Smooth Muscle Growth**
What is the function of Endothelin-1?
Potent Vasoconstrictor and acts as a MITOGEN for smooth muscle cells
What key factor is expressed by endothelial cells in plexiform lesions?
VEGF
What cytokines induce the formation of VEGF?
TGF-ß and PDGF
Where is serotonin stored (mainly)?
• what is its role in PAH?
• What PAH patients typically show higher concentrations of serotonin in their plasma?
Serotonin is mainly stored in the dense granules of platelets. It causes VASOCONTRICTION and PROLIFERATION of smooth muscle cells.
In patients with PRIMARY pulmonary hypertension their blood levels or Serotonin are typically elevated.
