Cardiovascular pathology

Question 1

most common cause of right sided heart failure

Answer 1

massive pulmonary embolism causing sudden blockage of a major pulmonary artery or the pulmonary bifurcation

Question 2

How does a PE lead to right sided heart failure

Answer 2

the pressure in the pulmonary arterial system rises dramatically. The right side of the heart does not have time to undergo compensatory change so cannot generate enough force to maintain an output. This results in acute right heart failure, which presents as circulatory collapse, shock and/or instantaneous death.

Question 3

commonest causes of slow damage to the right ventricle

Answer 3

COPD
pulmonary fibrosis
recurrent small pulmonary emboli

Question 4

what is a non-massive PE?

Answer 4

due to a medium sized embolus occluding a segmental pulmonary artery, resulting in a segment of lung being ventilated but not perfused.

Ventilation/perfusion defect

As a consequence there is respiratory compromise which usually manifests as pulmonary infarction with or without pleuritis and an effusion.

Question 5

what is a massive PE

Answer 5

Due to a massive embolus occluding a proximal pulmonary artery or the pulmonary artery bifurcation (saddle embolus)

as a consequence, blood cannot enter the lungs which causes a sudden increase in resistance to pulmonary blood flow and results in pulmonary hypertension.

Results in acute cor pulmonale

In addition, blood cannot pass through the lungs resulting in decreased filling of the left side of the heart= decreased preload= decreased CO–> presents as haemodynamic compromise