Pulmonary vascular circuit has a very low resistance Carries a volume of 70ml of blood. NORMAL
Normally Increased blood flow in lung bases as compared to the apices d/t gravity NORMAL PULMONARY VASCULATURE
Minimal blood flow to apices Inadequate LA pressure Vessel diameter in upper intercostal spaces is not more than 3mm Main pulmonary artery diameter is 16mm in males and 15mm in females .
An increase in blood pressure in the pulmonary artery , pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting n eventually heart failure Pulmonary hypertension
Sustained elevation of mean pulmonary arterial pressure to greater than 25 mmHg at rest or more than 30 mmHg during exercise, with normal pulmonary capillary wedge pressure and left ventricular end-diastolic pressure (<15 mm Hg) PAH
WHO Classification of pulmonary hypertension Group 1 . Pulmonary artery hypertension (PAH) Idiopathic Familial Group 2. Pulmonary hypertension with left heart disease Group 3 . Pulmonary hypertension associated with lung disease and/or hypoxaemia Group 4 . Pulmonary hypertension due to chronic thrombotic and/or embolic disease Group 5 . Miscellaneous ( sarcoidosis , histiocytosis X, lymphangiomyomatosis , compression of pulmonary vessels) )
CXR Hilar pulmonary arterial dilation. Loss of peripheral blood vessel markings OR Peripheral pruning Enlarged right atrium and right ventricle in advanced diseases PAH