Diurnal rhythm of central blood pressure during twenty-four-hour ambulatory monitoring

Abstract

It’s known that ABPM is better in diagnosing hypertension than office-based measurements. Growing evidence supports that cBP is stronger predictor of cardiovascular risk than brachial BP. Dipping status of subjects can be assessed based on night-to-day BP ratio derived from ABPM. However, there is no data regarding diurnal rhythm of central hemodynamics. Arteriograph 24 is suitable for 24-hour monitoring of both central and brachial BP. The aim of our study was to compare the 24-hour pattern of peripherial and central BP in same patients.Patients and methods24-hour aortic BP-monitoring was performed with Arteriograph 24 in 46 subjects (30 male, 16 female). Measurements were carried out with Arteriograph 24 – a combination of a “single” Arteriograph and an ABPM. Mean age of patients were 55.36 years. Their dipper status was assessed according to the ESH-guidelines and the circadian variation of central hemodynamics was determined as the difference of peripherial and central BP during day and night.ResultsOnly 7 of 46 subjects were non-dipper according to their brachial BP. All of them had elevated central BP at night. In contrast we observed elevated AIx and higher cBP during nighttime in further 30 cases who had dipping of nighttime brachial BP.ConclusionscBP have diurnal rhythm but the circadian variation of cBP is not necessarily parallel with the corresponding peripherial values. Theoretically elevated peripherial vascular resistance during night helps to maintain the appropriate cBP to provide the cerebral, coronary and renal perfusion. If this observation is confirmed by further large-scale trials the clinical implications of dipping status could be reconsidered.