thrombus
Pronunciation: THROM-bus
A blood clot that forms within a blood vessel and remains attached to its site of origin.
Full Definition
A thrombus is a blood clot that forms within the vascular system due to activation of the coagulation cascade, typically in response to endothelial damage, blood stasis, or hypercoagulable states (Virchow's triad). Unlike emboli, thrombi remain attached to their site of formation. In cardiovascular medicine, thrombus formation can occur in coronary arteries (causing acute coronary syndromes), cardiac chambers (particularly in atrial fibrillation or ventricular dysfunction), or peripheral vessels. Thrombus composition varies by location and flow conditions, with platelet-rich 'white' thrombi in high-flow arterial systems and fibrin-rich 'red' thrombi in low-flow venous systems. Treatment involves anticoagulation, antiplatelet therapy, or mechanical intervention depending on location and clinical presentation.
Usage
Usage note: Distinguish from 'embolus' (traveling clot); plural is 'thrombi'.
In Context
- "Coronary angiography revealed acute thrombus formation in the proximal LAD artery." — Primary PCI procedure report
- "Transesophageal echocardiography identified left atrial appendage thrombus prior to cardioversion." — Pre-procedural imaging assessment