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Changes of plasma C-type natriuretic peptide during head-up tilt test in children with vasovagal syncope and its significance

??Objective??To explore the changes of plasma C-type natriuretic peptide??CNP?? in children with VVS. Methods??Thirty-one children??male 16?? female 15?? with VVS were included in the study??and all of them were diagnosed by detailed history taking?? physical examination and related laboratory inspections as well as head-up tilt test. The mean age was ??11±3?? years. Another 32 healthy children??male 17??female 15?? were taken as a control group??who were confirmed as healthy by detailed history??physical examination??and standing test??etc. Their mean age was??11±2?? years. Finapres Medical System??Finapres Medical System-FMS??the Netherlands?? was used to continuously monitor heart rate and blood pressure during HUTT??and ECG was performed. Sandwich immunoluminescence assay was used to test plasma CNP. Results??No differences were found in age??height??weight??supine systolic blood pressure??diastolic blood pressure and mean arterial pressure between VVS group and control group??P?? 0.05??. The plasma CNP level in VVS group was higher than that of control group in supine position???35.7±21.5??ng/L vs. ??23.2±8?? ng/L??P??0.01??. The plasma CNP was positively correlated with syncope frequency in VVS group??r??0.85??P??0.05??. However??no significant differences were found in plasma CNP between supine position and positive response in HUTT in VVS group???36.3±21?? ng/L vs. ??42±57?? ng/L??P??0.05??. Conclusion??The plasma CNP level in VVS group is higher than that of control group in supine position. The plasma CNP is positively correlated with syncope frequency in VVS group??which might play a role in the pathogenesis of VVS in children.