Vascular Diseases of Lungs

Pulmonary Hypertension

It is the increase in blood pressure in pulmonary arteries, veins and capillaries .

It leads to shortness of breath, dizziness and faintingM:F ratio 1:3Prevalence 15/million

Primary vs secondary

Presentation

Gradual onset of dyspnea and fatigue

Non productive cough

Syncope

Peripheral edema (ankle swelling)

Types

Arterial

Venous

Capillary

PathogenesisArterial: vasoconstriction due to vascular hyper-reactivity due to endothelial dysfunction (low PG, NO, high endothelin)– thickening and fibrosis of blood vessels – increase pulmonary arterial pressure – increase work load to the right side of the heart – right ventricular hypertrophy – RV failure – less blood to the left side of heart – hypoxemia – systemic congestion of blood (liver, lower ankle swelling, increased jugular veinous pressure)

PathogenesisVenous: no obstruction of blood flow – Due to left side heart failure – pooling and congestion of blood in lungs – increase hydrostatic pressure in pulmonary veins – chronic process – pulmonary hypertension

Pathogenesis

Capillary: due to lung disease eg. idiopathic pulmonary fibrosis.

There is generalized fibrosis of the alveolar walls – changes of the capillary network due to loss and fibrosis – arterialization of capillaries – increase resistance and pressue

Generalized hypoxia - vasoconstriction

CausesWHO group I: pulmonary arterial hypertension: disease of arteries, idiopathic pulmonary arterial hypertension, vasculitis, autoimmune diseaseWHO group II: Pulmonary hypertension associated with heart diseaseWHO group III: Pulmonary hypertension associated with lung disease: COPD, interstitial pneumonia..

WHO group IV: Pulmonary hypertension due to multiple pulmonary thromboembolismWHO group V: Miscellaneous: others eg. Sarcoidosis

Diagnosis

Dyspnea, syncope

Elevated jugular venous pressue

Congested liver

Ankle edema

Clubbing of fingers

High pulmonary arterial pressure

Pulmonary Thromboembolism

Pulmonary Thromboembolism

Common clinical problem

Can be fatal

Frequently missed

Difficult to diagnose

95% thromboembolism of DVT (popliteal veins and larger veins of lower limb)

Predisposing factors for thrombosis

Risk factors:

Prolonged bed rest, following major surgery, severe trauma, congestive heart failure, contraceptive pills, cancer

Presentation

60-80% are asymptomatic

5% cause sudden death

10-15% cause lung infarction, presenting as sudden dyspnea, severe chest pain

3% are multiple and cause pulmonary hypertension

Consequences of pulmonary thromboembolism:

1 .Fatal if it is large (Saddle embolus)

2 .Infarction :

small emboli, distal occlusion of pulmonary arteries, can be multiple, wedge shape, hemorrhagic “red” infarct

3 .Pulmonary hypertension: multiple, chronic

4 .Cor pulmonale

Diagnosis

Needs high index of suspicion

Presentation: pleuritic chest pain, severe, with sudden dyspnea, history of DVT or risk for thrombosis

Imaging: x ray, CT scan, V/Q scan