Influence of the gender on the relationship between heart rate and blood pressure

Blood Pressure (BP) and Heart Rate (HR) provide information on clin-ical condition along 24h. Both signals present circadian changes due to sympa-thetic/parasympathetic control system that influence the relationship between them. Moreover, also the gender could modify this relation, acting on both con-trol systems. Some studies, using office measurements examined the BP/HR re-lation, highlighting a direct association between the two variables, linked to sus-pected coronary heart disease. Nevertheless, till now such relation has not been studied yet using ambulatory technique that is known to lead to additional prog-nostic information about cardiovascular risks. In order to examine in a more ac-curate way this relation, in this work we evaluate the influence of gender on the BP/HR relationship by using hour-to-hour 24h ambulatory measurements. Data coming from 122 female and 50 male normotensive subjects were recorded using a Holter Blood Pressure Monitor and the parameters of the linear regression fit-ting BP/HR were calculated. Results confirmed those obtained in previous stud-ies using punctual office measures in males and underlined a significant relation between Diastolic BP and HR during each hour of the day in females; a different trend in the BP/HR relation between genders was found only during night-time. Moreover, the circadian rhythm of BP/HR is similar in both genders but with different values of HR and BP at different times of the day

Heart rate, synchrony and arterial hemodynamics

Heart rate is a conventional index quantifying the pulsatile action of the heart and is a basic parameter used throughout medical history and practice. However, modern science often places relatively little emphasis on heart rate in relation to the oscillatory nature of blood flow in the circulatory system, and the unyielding cyclic stress on the heart and blood vessels. Heart rate is relevant not only as an elemental measure, but also as a statistical entity and a possible confounding factor when considering its interaction with vascular hemodynamics. Pulse pressure amplification from the central aorta to peripheral arteries increases with heart rate. This has significant implications when assessing vascular function based on peripheral (brachial) pressure measurements, as the pressure changes at the central aorta with changes in arterial stiffness (as occurs with age) can be markedly different from changes at the peripheral site at different heart rates. Similarly, heart rate is a significant parameter when assessing cardiac and vascular implications of anti-hypertensive drug treatments. Heart rate, itself an independent parameter of cardiovascular risk, should also be considered in the statistical treatment of cardiovascular risk factors in large epidemiological studies. Disturbance in the regular pulsatile action of the heart due to altered synchrony of the cardiac chambers leads to heart failure, which can be treated with resychronization therapy. Cardiovascular models show that arterial stiffness can significantly affect the modification of parameters associated with cardiac resynchronization therapy. Thus, pulsatile hemodynamic parameters play a significant role when associated with both regular heart rate and with disturbed synchrony of the contracting heart chambers affecting the pump function of the heart.13 page(s