Cerebral blood flow velocities monitored by transcranial Doppler during cardiac catheterizations in children

Transcranial Doppler (TCD) was used to evaluate brain circulation during cardiac catheterizations in 32 children requiring pulmonary (n=10) or aortic balloon dilatations (n=2), ductus arteriosus coil insertions (n=5), or angiography (n=15). Cerebral blood flow velocity (CBFV) in the middle cerebral artery was measured before (baseline), during, and after each procedure (mean+/-95%ci). High-intensity transient signals (HITS) were also detected during these maneuvers. Balloon angioplasty decreased CBFV by 63+/-11% from baseline (P < 0.01). Shorter durations of the inflation cycle resulted in earlier CBFV recovery (r=0.78). During angiography, CBFV increased by 11+/-4% (P < 0.01) in all except one case that showed retrograde diastolic flow. Mean total HITS count was 44 (95%ci.limits: 27,74). These signals were more frequently found in septal defects or systemic arterial manipulations. Pediatric cardiac catheterization may impose transient fluctuations in brain perfusion as indicated by TCD, but their clinical implications are uncertain. CBFV changes during balloon angioplasty emphasize the importance of rapid inflation/deflation cycles. TCD can monitor such changes and evaluate preventive measures.