Bela Benczur

Reference values of aortic pulse wave velocity in a large healthy population aged between 3 and 18 years.

Objective: The measurement of aortic pulse wave velocity (PWVao) is an accepted marker in stratifying individual cardiovascular risk in adults. There is an increasing volume of evidence concerning impaired vascular function in different diseases in paediatric populations, but, unfortunately, only a few studies are available on the measurement of normal PWVao values in children. The aim of our study was to determine the reference values of PWVao in a large healthy population using a newly developed technique. Methods: Three thousand, three hundred and seventy-four healthy individuals (1802 boys) aged 3–18 years were examined by an invasively validated, occlusive, oscillometric device. Results: The mean PWVao values increased from 5.5 ± 0.3 to 6.5 ± 0.3 m/s (P < 0.05) in boys and from 5.6 ± 0.3 to 6.4 ± 0.3 m/s (P < 0.05) in girls. The increase, however, was not constant, and the values exhibited a flat period between the ages of 3 and 8 years in both sexes. The first pronounced increase occurred at the age of 12.1 years in boys and 10.4 years in girls. Moreover, between the ages of 3 and 8 years, the brachial SBP and mean blood pressures increased continuously and gradually, whereas the PWVao remained unchanged. By contrast, beyond the age of 9 years, blood pressure and aortic stiffness trends basically moved together. Conclusion: Our study provides the largest database to date concerning arterial stiffness in healthy children and adolescents between the ages of 3 and 18 years, and the technology adopted proved easy to use in large paediatric populations, even at a very young age.

DIURNAL RHYTHM OF CENTRAL HEMODYNAMICS DURING TWENTY-FOUR-HOUR AMBULATORY MONITORING

Objective: 24-hour ABPM is a better method for diagnosing hypertension and predicting BP-related complications than office-based measurements. In addition increasing amount of evidences supports that central (aortic) BP is stronger predictor of cardiovascular risk than the conventional brachial BP. Dipping status of subjects can be easily assessed according to night-to-day brachial BP ratio provided by ABPM. However there is no data in the literature whether the diurnal rhythm of central aortic systolic blood pressure (CASP) follows the same pattern as the brachial one (BrSP). The aim of our study was to compare the 24-hour pattern of peripherial and central blood pressure in the same individuals. Design and method: 24-hour monitoring of aortic and brachial blood pressure was performed with Arteriograph24, a newly developed upper-arm cuff oscillometric device in 55 hypertensive and normotensive subjects, 36 males and 19 females. The 24-hour systolic pressure amplification, the difference of brachial and aortic cystic pressures measured simultaneously was calculated. Augmentation index (AIx) which is one of the main determinants of central blood pressure was also assessed. Results: The nocturnal fall of CSP was significantly lower than the peripheral pressure fall in 47 subjects of 55. 24-hour systolic pressure amplification was significantly lower during the night than during the day. In contrast to the nighttime decrease of central-to-peripherial systolic pressure Augmentation index was increased during the night. Conclusions: Central hemodynamic parameters (AIx, cSBP) also have diurnal rhythm but in contrast to peripherial BP the circadian variation of central BP is not necessarily parallel with the corresponding peripherial values. Theoretically elevated peripherial vascular resistance (which is represented by the augmentation index) during nighttime helps to maintain the appropriate central systolic pressure which is mandatory for the perfusion of the brain, heart and kidneys.