2004 Volume 17 Issue 2 Pages 76-78
High-intensity transient signals (HITS) revealed by transcranial Doppler (TCD) can be used to detect microthrombi as indicators of cerebral infarction. We postulated that HITS could also be used to detect bacterial clumps in the blood of patients with cardiovascular infection. We measured inflammatory reactions in laboratory tests and recorded TCD in the middle cerebral artery (MCA) and internal carotid artery (IC) continuously for 30 min in patients with pacemaker lead infection and infectious endocarditis. HITS was detected in two cases, and these decreased concomitantly with reduction of the inflammatory reaction. HITS revealed by TCD can detect emboli more than 10 μm in diameter. As bacterial clumps measure 0.3-30 μm, the signals represented as HITS may have been microemboli or bacterial clumps. Because they decreased with improvement of the inflammatory reaction, HITS may be useful not only clinically but also for monitoring of pathological status.
