Dynamics of Sequential Large Pulmonary Emboli

Abstract

The clinical importance of further clarifying the fundamental character of pulmonary embolism (PE) is amplified by recent statistics which estimate the total annual United States incidence of PE at 630,000 (1). Of the 89% of patients who survive the first hour, it is estimated that the diagnosis of PE is missed in 71% of the cases, and the total death rate sums to 200,000, almost 32% of the estimated incidence. Since early diagnosis and treatment can significantly reduce mortality (82% when diagnosed and 30% when undiagnosed), and in the light of newly available treatment modalities it is important not only to develop new and simpler methods of detecting the presence of PE , but also to provide information which will be helpful to the physician in selecting appropriate therapy (2). Since most emboli to the pulmonary vasculature originate in the leg and pelvic veins it is logical to view preventative therapy together with monitoring the development of venous thrombosis as a first line of defence in the prevention of PE in a selected class of high risk patients (3,4,5). Although noninvasive methods for detection of venous thrombosis are currently available, their sensitivity is limited to detecting hemodynamically significant thrombi while they are not feasible as a general screening technique (3, 6).