Cardiology patient pages. Pulmonary embolism and deep vein thrombosis.

Abstract

The heart pumps oxygenated blood through the aorta to smaller arteries. After the blood supplies nutrients to vital organs, it returns through veins for reoxygenation in the lungs (Figures 1 and 2⇓). Blood clots called deep vein thrombi (DVT) often develop in the deep leg veins. Pulmonary embolism (PE) occurs when clots break off from vein walls and travel through the heart to the pulmonary arteries. The broader term venous thromboembolism (VTE) refers to DVT, PE, or to a combination of both. Figure 1. The arterial (red) and venous systems (blue) are depicted. The left ventricle (LV) ejects oxygenated blood into the aorta, which circulates blood to vital organs. Deoxygenated blood travels through the venous system to the right atrium, right ventricle, and pulmonary artery. Adapted with permission from MediClip, Clinical Cardiopulmonary Images 1997, CCP01026.TIF, Williams & Wilkins, Baltimore, Md. Figure 2. Deoxygenated blood returns to the heart and lungs for reoxygenation. SVC indicates superior vena cava; IVC, inferior vena cava; RA, right atrium; RV, right ventricle; and PA, pulmonary artery. Adapted with permission from MediClip, Clinical Cardiopulmonary Images 1997, CATHRHT.TIF, Williams & Wilkins, Baltimore, Md. VTE poses a public health threat with an estimated incidence in the United States of 250 000 to 2 million cases per year. Predisposition to VTE arises from acquired conditions, inherited disorders, or both. Many of the acquired risk factors can be modified, thus lessening the likelihood of PE or DVT. Long-haul air travel is the most talked-about risk factor for PE. Other acquired risk factors include obesity, …