Development of new quantitative diagnosis machine to evaluate the Baroreflex sensitivity of an artery for patients with hypertension

Abstract

Text book in all medical school showed that the baroreflex system is one of the most important regulatory systems. When blood pressure increases, heart rate decrease and an artery is dilated with the baroreflex system. By decrease of cardiac output and arterial resistances, blood pressure returns to the normal value. However, there is no diagnostic method, which can measure the sensitivity of a baroreflex system of the artery by the simple methodology. We had challenged invention of the new machine, which could diagnose the sensitivity of the baroreflex system of not only a heart, but also an artery. In this system, the measurement sections are only an electrocardiography (ECG) and peripheral pulse wave. These time series is inputted into a personal computer system, and analyzed quantitatively. Responses of the artery were measured with pulse wave velocity (PWV) calculated from pulse wave transmission time from heart to an artery. In this system, the heart rate change corresponding to the blood-pressure change in time series sequence is observed. Delay time was measured by the cross correlation function. Slope of the blood pressure (BP) change and heart rate (HR) change showed the sensitivity of the baroreflex system of heart. Furthermore, this system can measure the sensitivity of the baroreflex system of an artery. Change of PWV in response to the BP change was observed. We found that significant correlation was observed in the time sequence between BP change and PWV change after delay time calculated from cross correlation. Clinical research was started through allowance of the Ethics Committee. Decreased sensibility in the hypertensive patient's baroreflex system was observed as a result of the clinical research. Furthermore, alteration of the baroreflex sensitivity before and after the drug administration was evaluated. For example, Azelnidipine, Calcium antagonists improved the baroreflex sensitivity of the artery in several cases. This system may be useful f- or the follow up of the hypertensive patients.

The cardiac, vasomotor, and myocardial branches of the baroreflex in fibromyalgia: Associations with pain, affective impairments, sleep problems, and fatigue

“…Previous attempts at noninvasive assessment of the vascular branch were based on pulse transit time (Vaschillo et al., 2012; Yambe et al., 2009), a surrogate for total peripheral resistance recorded using the Nexfin CO‐trek pulse contour method (Borgers et al., 2014), and of skin blood flow in the hand obtained using laser Doppler flowmetry (Porta et al., 2018). Invasive assessment of the vascular branch involves recording muscle sympathetic nerve activity (MSNA) bursts, usually from the peroneal nerve (Furlan et al., 2005; Marchi et al., 2016; Porta et al., 2017; Zamunér, Barbic, et al., 2015).…”

Time domain measurement of the vascular and myocardial branches of the baroreflex: A study in physically active versus sedentary individuals

“…Although vascular regulation is of essential relevance in BP regulation and in the processes leading to essential hypertension, up to now few attempts have been made to measure the vasomotor branch of the baroreflex. Moreover, most of these attempts (Vaschillo, Vaschillo, Buckman, Pandina, & Bates, ; Yambe, Sugita, & Yoshizawa, ) have used as the reflex output measure pulse transit time (PTT, the time interval between the occurrence of the R wave and arrival of the pulse at a peripheral location). Although PTT correlates with arterial wall stiffness, it is strongly dependent on BP and myocardial contractibility, and as such it has been traditionally used as an index of β 1 ‐adrenergic influences on myocardial contractility (Contrada, Del Bo, Levy, & Weiss, ).…”

Measurement of vascular tone and stroke volume baroreflex gain

“…To the best of our knowledge, only one study has measured VT-BRS gain (Yambe, Sugita, & Yoshizawa, 2009) and one study has measured SV-BRS gain (Yasumasu, Abe, Oginosawa, Takahara, & Nakashima, 2005). Yet, the VT-BRS and SV-BRS arches are of no less importance to physiological health than the HR-BRS.…”