Association between 24-hour ambulatory heart rate and arterial stiffness

Clinical and experimental studies point to a positive association between c arotid-femoral pulse wave velocity (PWVcf) and casual heart rate. However, an association with 24-h ambulatory heart rate has never been investigated, Twenty-four hour ambulatory heart rate and PWVcf (automatic computerised t echnique) were simultaneously measured in 213 subjects with untreated mild- to-moderate essential hypertension. It was found that mean ambulatory heart rate was higher in women than in men but the difference reached statistica l significance only in those below 50 years of age during pendent of gender . night-time measurements. As well as age and blood pressure, 24-h ambulato ry heart rate was also an independent factor influencing PWVcf. Independent of gender, the relationship between PWVcf and ambulatory heart rate was st ronger in patients over 50 years of age. Casual heart rate was not a signif icant determinant of PWVcf in this population. In conclusion, ambulatory he art rate contribution to explain pulse wave velocity is more important than casual heart rate. The relationship between 24-h heart rate and pulse wave velocity is stronger for subjects older than 50 years of age independent o f gender.