When venous

thrombi are

dislodged

Embolize to : pulmonary arterial circulation

or, paradoxically, to the arterial circulation

through a patent foramen ovale or atrial

septal defect

Hypoxemia Increased arteriolar-arterial O2

tension gradient

Anatomic dead space increases

Physiologic dead space increases

Increased pulmonary vascular resistance

Impaired gas exchange

Alveolar hyperventilation

Decreased pulmonary

compliance

Increased airway resistance

RV wall tension rises and causes further

RV dilation and dysfunction

Interventricular septum bulges into

and compresses an intrinsically

normal left ventricle

RV contraction continues

even after the left ventricle

(LV) starts relaxing at end-

systole

Diastolic LV impairment

Reduced LV distensibility and impaired LV

filling during diastole

Compression of

the right

coronary artery

Diminish

subendocardial

perfusion

Limitation of

myocardial

oxygen

supply

Precipitate myocardial ischemia and RV infarction

Fall in left-ventricular cardiac output

and systemic arterial pressure

Circulatory Collapse Death