disorders of pulmonary circulation Flashcards
pulmonary embolism
consequence of a blood clot that then breaks off and travels through system causing blockage or obstruction of flow
pulmonary hypertension
elevated pressure in the pulmonary arteries
mean pulmonary artery pressure at rest is
less than 20mmHg
pulmoary hypertension caused by
Group 1- Idiopathic, drugs, connective tissue disease, HIV
Group 2- LEFT VENTRICLE DYSFUNCTION, Valvular heart disease
Group 3- chronic lung disease - COPD
Group 4- chronic thromboembolic pulmonary hypertension
Group 5- unclear
risk factors for pulmonary hypertension
family
connective tissue disease
congential heart disease
HIV
chronic hypoxic lung disease
initial trigger: vascular injury or stress
hypertension
abnormal stress to the small pulmonary arteries
genetic mutations
chronic thromboembolic disease
abnormal changes to pulmonary arteries in hypertension
endothelial cell dysfunction- losses ability to regulate tone and growth- narrows
imballance causes vasconstriction, cell proliferation and blood clot
inflammation of vessel
thicken/ scaring or overgrowth of cells in intima
increased pulmonary vascular resistance
arteires stiffen and narrow PVR rises
decrease blood flow
elevates pressure
right ventricular strain or failure
right ventricle= high afterload
thickens to overcome pressure
RV dilates
CTPEH
PERSISTANT MECHANICAL OBSTRUCTION IN PULMONARY ARTERIES DUE TO THROMBOEMBOLISIM
thrombi incorporated in vessel wall lead to fibrosis and thickening and luminal narroing
this persistant obstruction increase PVR and pressure
symptoms of CTEPH early
exertional dyspnoea
fatigue
lethargy
symptoms of CTEPH late
exertional chest pain
exetional syncope
peripheral oedema
sings of CTEPH
Cardiac: e.g., loud, palpable second heart sound (as pulmonary valve closes forcefully because of the high pressure in pulmonary arteries
Elevated jugular venous pressure (JVP)
Hepatomegaly (pulsatile, tender liver)
Peripheral oedema
Ascites
Pleural effusions
Respiratory: Hypoxaemia, reduced breath sounds at lung bases
pulmonary embolism causes
thromboembolism
fat embolisim
amniotic fluid embolism
tumour embolism
air embolism
risk factors for PE
surgery
trauma
old age
imbolisation
cancer
fractures
pregancy
trauma
pathophysiology of THROMBOEMBOLIC PE
mechanical obstruction leads to impaired blood flow
causes ventilation perfusion
leads to hypoxaemia
increadsed PVR strains RV causes heart fail and shock
fat embolism PE
fat globules enter venous circulation from injured marrow or adipose tissue
free fatty acids in circulation
inflammatory cytokines releasesd
obstruction by fat
platlet aggrefation and inflammation process leads to oedema and hypoxaemia
air embolism PE
air enters venous system- large volumes obstruct outflow tract
reduced preload right hear failure and hypoxia
amniotic fluid embolism PE
entry of amniotic fluid triggers inflammation and thombotic cascades
tumour embolism
Tumour cells enter pulmonary arteries and obstruct microvasculature
Can lead to progressive pulmonary hypertension and hypoxia
general symptoms of PE
Acute dyspnoea (most common)
Pleuritic chest pain
Tachypnoea
Tachycardia
Hypoxaemia
Cough ± haemoptysis
Syncope (in massive PE)
