title: Cerebral High-Intensity Transient Signals during Pediatric Cardiac Catheterization: A Pilot Study Using Transcranial Doppler Ultrasonography.
abstract: Cerebral emboli are one potential cause of acute brain injury in children with congenital heart disease (CHD) undergoing cardiac catheterization. In this pilot study using transcranial Doppler (TCD) ultrasonography, we sought to evaluate the incidence, burden, and circumstances of cerebral high-intensity transient signals (HITS), presumably representing emboli, during pediatric cardiac catheterization.
  
  
  
  Emboli monitoring of the right middle cerebral artery was performed in five children. HITS, counted offline, were defined as unidirectional signals associated with audible "chirp" and sinusoidal correlation. HITS were grouped as single, >10 HITS ("cluster"), or HITS "with curtain effect" per 3-5 cardiac cycles. Cerebral blood flow velocity (CBFV) and pulsatility index (PI) were recorded after anesthetic induction (baseline).
  
  
  
  Total HITS in the cohort was 1,697 (790 single HITS, 606 HITS within clusters, and 301 HITS within curtains). HITS in clusters and curtains comprised 53% (907/1,697) of total HITS, and occurred in 44 clusters/curtains. Events associated with clusters/curtains included left ventricular angiography (39%; 17/44), right ventricular angiography (16%; 7/44), device placement (16%; 7/44), heparin bolus (9%; 4/44), pulmonary artery angiography (9%; 4/44), venous access (5%; 2/44), right atrial angiography (2%; 1/44), arterial access (2%; 1/44), and hemodynamic measurements (2%; 1/44). No patient had clinically detectable neurologic injury.
  
  
  
  HITS are common during pediatric cardiac catheterization, and associated with procedural factors. Whether curtains/clusters are worse than single, repetitive HITS is unknown. Larger studies are needed to determine whether HITS are a marker of risk of neurologic injury from emboli during pediatric cardiac catheterization.
authors.affiliation: Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA.
authors.forename: Kerri L
authors.initials: KL
authors.lastname: LaRovere
authors.affiliation: Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA.
authors.forename: Kush
authors.initials: K
authors.lastname: Kapur
authors.affiliation: Department of Cardiothoracic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA.
authors.forename: Doff B
authors.initials: DB
authors.lastname: McElhinney
authors.affiliation: Sentient NeuroCare Services, Inc., Boston Children's Hospital and Harvard Medical School, Boston, MA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Razumovsky
authors.affiliation: Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA.
authors.forename: Barry D
authors.initials: BD
authors.lastname: Kussman
mesh_terms: D006328:Cardiac Catheterization / Q000009:adverse effects / Q000379:methods*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D010865:Pilot Projects; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*
keywords: cardiac catheterization; congenital heart disease; embolism; high-intensity transient signals; transcranial Doppler ultrasound