Reflex control of heart rate in normal subjects in relation to age: A data base for cardiac vagal neuropathy

Abstract

We examined the heart rate changes induced by forced breathing and by standing up in 133 healthy subjects in the age range 10-65 years in order to establish a data base for studies on parasympathetic heart rate control in autonomic neuropathy. Test results declined with age. Log-transformation was used to define the lower limit of normal (P0.10) and an uncertainty range (values between P0.10 and P0.025). The lower limit of normal decreased from 22 to 11 beats/min for forced breathing and from 26 to 16 beats/min for standing up, with age increasing from 10 to 65 years. No subject scored below and only two subjects scored in or below the uncertainty range for both tests. Lack of correlation between both tests (r = 0.17) documents the different afferent mechanisms of the reflex heart rate changes. In combination these two tests form a simple and reliable bedside method to establish cardiac vagal neuropathy.

Measures of cardiovascular autonomic nervous function: agreement, reproducibility, and reference values in middle age and elderly subjects

“…Especially in an elderly population this could be problematic, as is also shown by the higher number of missing values for this test. Poor agreement between heart-rate changes during deep breathing and after standing up has also been reported in a study of 133 healthy subjects in the age range of 10 to 65 years, where they found a correlation between EI difference and RR max of 0.17 and between EI difference and RR max/min of 0.14 [17]. An explanation might be the possible involvement of different afferent and efferent mechanisms [49].…”

“…For the computation of the BRS only spectral components were used that were within a defined band width (0.05-0.15 Hz) around the breathing frequency of six breaths per minute and with a squared coherence (γ 2 ) of 0.5 or higher. During an active change in position from lying to standing, the maximal change in RR interval (RRmax), defined as the difference between the mean RR interval during 1 min prior to standing up and the minimum RR interval within 15 s after standing up, was obtained [17]. Furthermore, we measured the maximum RR interval between 15 and 30 s after standing up divided by the minimum RR interval within 15 s after standing up (RRmax/min) [45] and the systolic blood pressure difference (SBP difference) after standing up calculated as the mean over 30 s during 1.5 to 2 min after standing up, minus the mean over 30 s prior to standing up [3].…”

“…Autonomic function has been reported to decrease in relation to age [8,9,10,11,12,13] and to differ between men and women [9,14,15]. Furthermore, diabetic patients have lower values on the Ewing battery [3,16,17,18,19], of the spectral analysis of HRV [4,16,20,21], and have a low BRS [5,22] in comparison with normal glucose tolerant control subjects. Besides their application in the assessment of cardiovascular autonomic function in diabetic patients, HRV and BRS are used in cardiology for risk stratification after myocardial infarction.…”

Autonomic nervous dysfunction in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA): possible pathogenic role of autoantibodies to autonomic nervous structures

“…Autonomic function was investigated performing a battery of standard cardiovascular (CV) tests, previously described and currently used for the diagnosis of diabetic autonomic neuropathy [15][16][17][18]: (i) heart rate variation during deep breathing (DB) at 6 cycles/min; (ii) heart rate variation with postural change: (a) lying to standing test (LS) and (b) the increase in heart rate during the first 15 s after standing (SHR); (iii) heart rate variation to a standard Valsalva manoeuvre; (iv) postural blood pressure (PBP) test. Each test was performed by means of a computerized method (Autocheck 'r' 3, vers.…”

“…5.1 software; K. Thomaseth and F. Bellavere, Padua, Italy); blood pressure was recorded using a Finapres device (Ohmeda, Denver, CO) for beat to beat blood pressure monitoring. The tests were graded as normal, borderline or abnormal with a score of 0, 1 or 2, respectively, using age-related normal ranges previously published [16,18]. Autonomic dysfunction was defined with a total score Ն 5 [19].…”