Why do you get right ventricular strain in thrombosis?
Due to increase in pulmonary vascular resistance (due to thrombus & vasoconstriction by hypoxia mediators) -> increased right ventricular afterload -> increased right ventricular muscle stretch, increased wall tension & right ventricular dilatation -> right ventricular strain
What are the physiological consequences of PE?
Blocks oxygenated blood to body
Hypoxic vasoconstriction (changes amount of ROS)
Increases resistances in pulmonary system
Gas exchange reduced -> increases alveolar dead space
Pleural effusion - fluid build up between pleural layer
What problems can chronic thromboembolic pulmonary HTN cause?
Right ventricle dilation
Tricuspid valve reguritation
Right ventricle failure
Change in ventricular pressure -> interventricular septum to shift to left
Compresses left ventricle -> less CO by left ventricle -> affects coronary arteries -> heart ischaemia
What does a decreased left ventricular compliance cause?
Diminished diastolic performance -> less filling
How does the pulmonary circulation react to hypoxia?
Pulmonary circulation reacts differently to hypoxia -> vasoconstriction -> sends blood to highly oxygenated areas in lungs
Pulmonary resistance vessels is insensitive to sympathetic & chemical control
How is an air embolism resolved naturally?
Air bubble is eventually reabsorbed by surrounding blood or tissue and recovery without intervention may occur
What is Virchow's triad?
Venous stasis
Hypercoagulability
Endothelial injury
Pathophys PE
Damage to endothelium of veins → vasoconstriction → limit blood flow → platelets adhere to endothelium & become activated by collagen & tissue factor → recruit more platelets → activates coagulation cascade → cleave fibrinogen to fibrin → fibrin clot formation → clot grows, reduces blood flow → increase venous pressure
Clot can breakdown → increased D-dimer
OR
High venous pressire -> part of clot breaks off to become thromboembolism -> travel towards heart & can become lodged in lungs → PE
What are the 2 types of thrombus?
Arterial
Venous
What are the possible fates of a thrombus?
Lysis - thrombolytic activity of blood
Propagation - increase in size
Organisation - thrombus becomes firm & greyish white
Canalisation - new lumen
Embolisation - part/all of thrombus becomes dislodged & travels through circulation