Cor pulmonale

Question 1

mechanism

Answer 1

V/Q ratio
if an individual alveoli is infected eg with pneumonia, it will not be ventilated by any oxygen. in order to compensate for this the capillaries supplying this site constrict, reducing perfusion to match.
in the case of COPD, this reduced hypoventilation is widespread, and therefore capillary constriction is also widespread. this increases vascular resistance, increasing the workload of the RV of the heart, which will eventually lead to failure
oedema will also result due to change in osmotic pressure due to blood flow backup

treating with O2 fro >15h/day tricks the lungs by increasing ventilation, thereby increasing perfusion and reducing the pulmonary HTN

Question 2

COPD

Answer 2

use of anti-muscarinic agents - tiotropium, ipratropium in conjunction with beta-agonists will improve prognosis and QOL more than monotherapy