Overview
Pulmonary hypoperfusion refers to a decrease in blood flow in the pulmonary circulation, thinning of the pulmonary arteries and branches, also known as pulmonary ischemia, and in severe cases compensatory dilatation of the bronchial arteries or the formation of collateral circulation supplying the lungs from branches originating directly from the aorta.
Causes
1. Obstructive lesions of the right heart and pulmonary artery or with right-to-left shunting (cyanosis mostly); such as tetralogy of Fallot, tricuspid atresia, tricuspid valve atresia, pulmonary atresia or stenosis, etc. and cardiac tamponade.
2. Pulmonary hypertension and emphysema.
3. Pulmonary artery thrombosis: e.g. embolism, stenosis of pulmonary artery branches, hypoplasia, etc.
Symptoms
Reduced blood flow in the pulmonary circulation is the main manifestation, and the patient may have cyanosis (cyanosis at the ends of the fingers and lips, etc.), as well as dyspnea or cardiopulmonary disease.
Examination
X-ray signs of decreased pulmonary blood flow: ① Flat or sunken pulmonary artery segments, or dilated after narrowing of the pulmonary artery. The right lower pulmonary artery trunk is thinned. Adult men are less than 1.1cm, women are less than 0.9cm, and pulmonary artery pulsation is weakened, ② pulmonary artery texture is thin and sparse. The transparency of the lung field is enhanced. Uneven thickness, twisted or increased vascular texture, even reticular, is seen in the lungs when the body arteries constitute collateral circulation; (3) the right atrium and right ventricle are enlarged; (4) pulmonary arteriography shows narrowing of the pulmonary arteries, generalized thinning, and abnormal collateral vessels.
Differential diagnosis
It is mainly seen in congenital heart disease with obstruction of right ventricular outflow tract or with right-to-left shunt, such as pulmonary stenosis, tricuspid stenosis or atresia, as well as tricuspid and tetralogy of fallot, etc. It can also be seen in primary or secondary pulmonary hypertension, as well as pulmonary heart disease. In addition, pulmonary artery embolism, alveolar emphysema, and pulmonary artery hypoplasia can cause decreased pulmonary blood flow. If the latter is unilateral, it can cause one-sided and regional reduction of pulmonary blood.
Treatment principle
Treat the primary cause of pulmonary hemopenia.