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Doppler microembolic signals in children with prosthetic cardiac valves
D Georgiadis1, M Preiss, A Lindner
1Department of Neurology, Martin-Luther University Halle-Wittenberg, Halle/Saale, Germany. dimitrios.georgiadis@medizin.uni-halle.de
Insights
Children with prosthetic cardiac valves show significantly higher Doppler microembolic signals (MES) compared to adults. This is likely due to smaller body size and faster heart rates in pediatric patients with mechanical valves.
Area of Science:
- Cardiovascular Medicine
- Biomedical Engineering
- Pediatric Cardiology
Background:
- Mechanical prosthetic valves are used to treat cardiac conditions in both children and adults.
- Monitoring for complications like microembolic signals (MES) is crucial after valve implantation.
- Differences in physiological factors between children and adults may influence MES prevalence.
Purpose of the Study:
- To evaluate the prevalence and counts of Doppler microembolic signals (MES) in children with prosthetic cardiac valves.
- To compare MES findings in pediatric patients with those in adult patients.
- To investigate potential factors contributing to observed differences in MES.
Main Methods:
- Transcranial Doppler ultrasound was used to monitor MES in the middle cerebral arteries of 9 children and 43 adults with ATS valves.
- Standard criteria were applied for on-line identification of MES.
- Data collected included heart rate, valve characteristics, patient height, INR, and neurological complications.
Main Results:
- MES prevalence and counts were significantly higher in children (100%, median 58) compared to adults (25.5%, median 55).
- Children had significantly faster heart rates and were smaller in size compared to adults.
- A positive correlation was found between patient size, heart rate, and MES counts.
Conclusions:
- Children with mechanical prosthetic valves exhibit significantly higher MES counts than adults.
- Hypothesized reasons include shorter distance from the aortic valve to the middle cerebral artery and faster heart rates in children.
- These findings highlight potential differences in embolic risk profiles between pediatric and adult patients with prosthetic valves.
Background And Purpose:
The aim of this study was the evaluation of the prevalence and counts of Doppler microembolic signals (MES) in children with prosthetic cardiac valves and their comparison to those obtained in corresponding adult patients.
Patients And Methods:
Nine children and 43 adults with ATS valves implanted in the aortic position were monitored over both middle cerebral arteries with transcranial Doppler ultrasound. MES were identified on-line according to standard criteria. Heart rate and rhythm, valve type, size and duration, patients' height, International Normalized Ratio, and prevalence of neurological complications were obtained from all study participants.
Results:
MES prevalence and counts were significantly higher in children compared with adult patients (100% versus 25.5% and 58 [18.5 to 115.5] versus 55 [2 to 10.5], median, 95% CI, respectively). No corresponding differences in valve duration of valve implant were evident, but children has heart rates and were significantly smaller compared with adults. A positive correlation between patients' size, heart rate, and MES counts was noted.
Conclusions:
MES counts in children with mechanical prosthetic valves are significantly higher compared with those in corresponding adults. We hypothesize that this is due to (1) the shorter distance between aortic valve and middle cerebral artery, since cavitation bubbles have a short life span and are bound to dissolve with time, and (2) the faster heart rate in children, resulting in a higher number of valve closures per minute.