ABSTRACT
The mortality rate from recognized PE varies from 2.3 to 28%.4,5 Two out of three deaths occur in the first hour, thus rapid approach to diagnosis and treatment; that is, recovery of pulmonary flow, can change the outcome.2,5
The principal criterion for characterizing acute massive PE is systemic arterial hypotension (systolic blood pressure < 90 mmHg).4 Hemodynamic decompensation in the form of arterial hypotension and right ventricular dysfunction is caused not only by the embolus, but also by the release of humoral factors such as serotonin and histamine. Hypoxia is a result of ventilation and perfusion mismatches, as well as vasoconstriction. The role of humoral factors and reactive vasoconstriction explains why the size of the emboli, as seen on CT, does not necessarily correlate to the severity of the clinical presentation.6
