Increased pulse wave velocity and not reduced ejection fraction is associated with impaired baroreflex control of heart rate in congestive heart failure

Abstract

It is known that baroreflex sensitivity (BRS) is impaired in cardiac patients with myocardial infarction (MI). Nevertheless, it is unknown whether factors other than a reduced ejection fraction play a role in the baroreflex impairment of these patients. Heart failure patients [congestive heart failure (CHF), n = 31, age 63 +/- 1.2 years, mean +/- SEM)], age-matched controls (n = 29) and coronary artery disease (CAD) patients without MI (n = 29) had RR interval and arterial blood pressure (BP) continuously monitored. Baroreflex function was assessed by the slope of the regression of RR interval, and BP responses to graded (-10, -20 and -40 mmHg) neck suction stimulation, the slope of bradycardic or tachycardic responses to spontaneous increases or reductions of SBP (sequence analysis) and the baroreflex efficiency index. Pulse wave velocity (PWV) was also measured.Compared with controls, CHF patients had RR interval and BP reflex responses to neck suction reduced by -36 and -54%, respectively (P < 0.01). By contrast, no differences were found between CHF and CAD patients. Similar reductions were observed for the sequence analysis (P < 0.01) in both CHF and CAD patients. Multiple regression analysis showed that in CHF and CAD patients, PWV and SBP and not ejection fraction were correlated with BRS. The baroreflex function is impaired in CHF patients, the extent and the degree of baroreflex impairment being similar to that of CAD patients without MI. In CHF and CAD patients, the baroreflex impairment correlates significantly with the increased PWV and not with ejection fraction.