Transmural pressure as a determinant of basic intrinsic heart rate

1976 ◽  
Vol 32 (10) ◽  
pp. 1295-1297 ◽  
Author(s):  
C. L. Pathak
Keyword(s):  
Heart Rate ◽  
Transmural Pressure ◽  
Intrinsic Heart Rate

Influence of cardiac innervation on intrinsic heart rate in dogs

1990 ◽  
Vol 258 (4) ◽  
pp. H1132-H1137 ◽  
Author(s):  
J. M. Evans ◽  
D. C. Randall ◽  
J. N. Funk ◽  
C. F. Knapp
Keyword(s):  
Heart Rate ◽  
Intrinsic Rate ◽  
Conscious State ◽  
Autonomic Innervation ◽  
Autonomic Activity ◽  
Cardiac Innervation ◽  
Cardiac Denervation ◽  
Ganglionic Blockade ◽  
Intrinsic Heart Rate

Intrinsic heart rate is defined as the rate at which the heart beats when all cardiac neural and hormonal inputs are removed. We determined the effect of prevailing autonomic innervation of the heart on the intrinsic heart rate in chronically maintained, sedated, normally innervated dogs (n = 14), and in 14 other dogs that had previously (greater than 12 day) undergone complete surgical cardiac denervation. Intrinsic rate was determined in both groups using the following two procedures: 1) pharmacological effector blockade; and 2) pharmacological ganglionic blockade. The intrinsic rate determined by effector blockade was 142.9 +/- 7.2 (SE) beats/min in the dogs with intact cardiac innervation. When the same treatment was given after total surgical cardiac denervation, intrinsic rate was 97.9 +/- 4.8 beats/min. Intrinsic heart rate was significantly (P less than 0.05) lower in surgically denervated dogs. Ganglionic blockade in surgically denervated animals yielded an intrinsic rate of 90.0 +/- 8.5 beats/min, which was again significantly lower than the corresponding value of 128.4 +/- 5.5 beats/min in normal dogs. There was no difference in the intrinsic heart rate as determined by effector vs. ganglionic blockade in either group of dogs. An additional six dogs were subjected to selective surgical sinoatrial nodal parasympathectomy; their intrinsic rate (effector blockade) in the conscious state was 115.8 +/- 4.3 beats/min; this was significantly lower than the corresponding value for normal dogs and significantly greater than in dogs subject to total surgical cardiac denervation. The lower rate observed in the totally denervated and selectively denervated dogs after effector and/or ganglionic blockades implies that intrinsic heart rate depends on the level or nature of prevailing autonomic activity.

TOBANUM /GYKI-41099/ EFFECT ON INTRINSIC HEART RATE

1980 ◽  
pp. 273-276
Author(s):  
éva Péterfai ◽  
B. Gachályi ◽  
A. Káldor
Keyword(s):  
Heart Rate ◽  
Intrinsic Heart Rate

scholarly journals PLB Drives the Kinetics of the Ca2+ Clock in Mouse Isolated Sinoatrial Nodal Cells and the Intrinsic Heart Rate in vivo

2014 ◽  
Vol 106 (2) ◽  
pp. 631a
Author(s):  
Syevda Sirenko ◽  
Ismayil Ahmet ◽  
Edward G. Lakatta
Keyword(s):  
Heart Rate ◽  
Intrinsic Heart Rate ◽  
Kinetics Of

scholarly journals Decreased maximal heart rate with aging is related to reduced β-adrenergic responsiveness but is largely explained by a reduction in intrinsic heart rate

2008 ◽  
Vol 105 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Demetra D. Christou ◽  
Douglas R. Seals
Keyword(s):  
Heart Rate ◽  
Maximal Oxygen Consumption ◽  
Older Men ◽  
Exercise Heart Rate ◽  
Maximal Heart Rate ◽  
Adrenergic Stimulation ◽  
Ganglionic Blockade ◽  
Intrinsic Heart Rate ◽  
Age Related ◽  
Aerobic Exercise Capacity

A decrease in maximal exercise heart rate (HRmax) is a key contributor to reductions in aerobic exercise capacity with aging. However, the mechanisms involved are incompletely understood. We sought to gain insight into the respective roles of intrinsic heart rate (HRint) and chronotropic β-adrenergic responsiveness in the reductions in HRmax with aging in healthy adults. HRmax (Balke treadmill protocol to exhaustion), HRint (HR during acute ganglionic blockade with intravenous trimethaphan), and chronotropic β-adrenergic responsiveness (increase in HR with incremental intravenous infusion of isoproterenol during ganglionic blockade) were determined in 15 older (65 ± 5 yr) and 15 young (25 ± 4 yr) healthy men. In the older men, HRmax was lower (162 ± 9 vs. 191 ± 11 beats/min, P < 0.0001) and was associated with a lower HRint (58 ± 7 vs. 83 ± 9 beats/min, P < 0.0001) and chronotropic β-adrenergic responsiveness (0.094 ± 0.036 vs. 0.154 ± 0.045 ΔHR/[isoproterenol]: P < 0.0001). Both HRint ( r = 0.87, P < 0.0001) and chronotropic β-adrenergic responsiveness ( r = 0.61, P < 0.0001) were positively related to HRmax. Accounting for the effects of HRint and chronotropic β-adrenergic responsiveness reduced the age-related difference in HRmax by 83%, rendering it statistically nonsignificant ( P = 0.2). Maximal oxygen consumption was lower in the older men (34.9 ± 8.1 vs. 48.6 ± 6.7 ml·kg−1·min−1, P < 0.0001) and was positively related to HRmax ( r = 0.62, P < 0.0001), HRint ( r = 0.51, P = 0.002), and chronotropic β-adrenergic responsiveness ( r = 0.47, P = 0.005). Our findings indicate that, together, reductions in HRint and chronotropic responsiveness to β-adrenergic stimulation largely explain decreases in HRmax with aging, with the reduction in HRint playing by far the greatest role.

The effects of exercise and changes in body temperature on the intrinsic heart rate in man

1970 ◽  
Vol 79 (4) ◽  
pp. 488-498 ◽  
Author(s):  
Anthony D. Jose ◽  
Frank Stitt ◽  
D. Collison
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Intrinsic Heart Rate
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