Transcranial Doppler detection of cerebral microemboli during left heart catheterization

The role of transcranial Doppler ultrasonography (TCD) in individual risk a ssessment of embolic complications and the development of prevention strate gies during coronary angiography remains to be determined. The purpose of t his study was to assess the prevalence, time of occurrence and potential si gnificance of microembolic signals (MES) detected with TCD during femoral l eft heart catheterization. TCD monitoring of the right and left middle cere bral artery was performed in 51 consecutive patients (36 men, 15 women) who were referred for coronary angiography. Percutaneous coronary angioplasty was performed during the same procedure in 16 patients. MES were counted ma nually during and after (offline analysis) the procedure. Two patients were excluded from analysis because of the absence of an adequate acoustic temp oral window. No neurological event occurred within 24 h in the 49 included patients. MES were detected in all except 2 patients (mean number 17.1 +/- 12.8 per patient), mainly during left ventriculography (38%) and contrast m edia injection into the coronary arteries (55%), suggesting their gaseous o rigin. There was no statistically significant association between the numbe r of MES and patient age, cardiovascular history and risk factors, or cathe terization results. The presence of coronary artery disease was inversely r elated to the number of MES (15.8 +/- 0.3 compared to 21.8 +/- 0.2 per pati ent when a normal angiogram was present; p < 0.05). In conclusion, although asymptomatic microemboli commonly occur during left heart catheterization, the majority of them are probably of gaseous origin, since they occurred p redominantly during contrast media injection in this study, and were not re lated to cardiovascular history or to atheroma risk factors. Because air em bolism has been reported to be harmful, attempts to reduce its occurrence d uring catheter-based procedures could be pertinent. Copyright (C) 2001 S. K arger AG, Basel.