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Assessment of Cerebral Lateralization in Children using Functional Transcranial Doppler Ultrasound fTCD
Published on: September 27, 2010
Cerebral High-Intensity Transient Signals during Pediatric Cardiac Catheterization: A Pilot Study Using Transcranial
Kerri L LaRovere1, Kush Kapur1, Doff B McElhinney2
1Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA.
Insights
High-intensity transient signals (HITS), presumed emboli, are common during pediatric cardiac catheterization. These signals are linked to specific procedures, but their association with neurological injury requires further investigation.
Area of Science:
- Pediatric Cardiology
- Neurology
- Medical Imaging
Background:
- Cerebral emboli can cause acute brain injury in children with congenital heart disease (CHD).
- Cardiac catheterization in pediatric patients with CHD carries a risk of cerebral emboli.
- Transcranial Doppler (TCD) ultrasonography is a tool for monitoring cerebral blood flow.
Purpose of the Study:
- To evaluate the incidence and burden of cerebral high-intensity transient signals (HITS) during pediatric cardiac catheterization.
- To identify procedural circumstances associated with HITS in children with CHD.
- To assess the potential link between HITS and neurological injury in this population.
Main Methods:
- Utilized TCD ultrasonography to monitor the right middle cerebral artery in five pediatric patients.
- Defined and categorized HITS offline based on signal characteristics (single, cluster, curtain effect).
- Recorded cerebral blood flow velocity (CBFV) and pulsatility index (PI) as baseline measures.
Main Results:
- A total of 1,697 HITS were detected, with 53% occurring in clusters or with a curtain effect.
- Procedural events like left ventricular angiography and device placement were associated with HITS clusters/curtains.
- No patient in the study experienced clinically detectable neurological injury.
Conclusions:
- HITS are frequently observed during pediatric cardiac catheterization and are associated with specific procedural factors.
- The clinical significance of different HITS patterns (single vs. cluster/curtain) remains unclear.
- Larger studies are necessary to determine if HITS serve as a marker for neurological injury risk in pediatric cardiac catheterization.
Background And Purpose:
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.
Methods:
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).
Results:
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.
Conclusions:
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.
