Heart rate during

After 10 days of exposure, reduced social behavior and reduced exploratory behavior were observed in rats exposed to 100 ppm trichloroethylene 6 hours per day 5 days per week for a total of 5 weeks (Silverman and Williams 1975). In rats exposed to 50 or 100 ppm trichloroethylene 8 hours/day, 5 days/week for 6 weeks, effects on sleep patterns were observed (Arito et al. 1994a). At 50 ppm decreased wakefulness was observed during the exposure. Effects remaining at 22 hours after the end of the 6-week exposure included decreased heart rate during sleep at 50 ppm and decreased wakefulness after exposure of 100 ppm (Arito et al. 1994a). Based on the 50-ppm LOAEL identified in the Arito et al. (1994a) study, an intermediate-duration inhalation MRL of 0.1 ppm was calculated as described in the footnote in Table 2-1. 

The second factor that exerts control on heart rate is the release of the catecholamines, epinephrine and norepinephrine, from the adrenal medulla. Circulating catecholamines have the same effect on heart rate as direct sympathetic stimulation, which is to increase heart rate. In fact, in the intact heart, the effect of the catecholamines serves to supplement this direct effect. In a denervated heart, circulating catecholamines serve to replace the effect of direct sympathetic stimulation. In this way, patients who have had a heart transplant may still increase their heart rate during exercise. 

Pharmacokinetic/pharmacodynamic model using nonlinear, mixed-effects model in two compartment, best described time course of concentration strong correlation with creatinine clearance predicted concentration at the efi ect site and in reduction of heart rate during atrial fibrillation using population kinetic approach... 

Furedy JJ, Algan O, et al (1999) Sexually dimorphic effect of an acute smoking manipulation on skin resistance but not on heart-rate during a cognitive verbal task. Integr Physiol Behav Sd 34(4) 219-226... 

See Table 11-2. Resting bradycardia and a reduction in the heart rate during exercise are indicators of propranolol s 3-blocking effect, and changes in these parameters may be used as guides for regulating dosage. Propranolol can be administered twice daily, and slow-release preparations are available. 

Hurley, J.A. (1996). Metabolic rate and heart rate during trained dives in adult California sea lions. Ph.D. Thesis, University of California, Santa Cruz. 

Antihypertensives of all kinds hypotension may complicate anaesthesia, but it is best to continue therapy. Hypertensive patients are particularly liable to excessive rise in blood pressure and heart rate during intubation, which can be dangerous if there is ischaemic heart disease. Postoperatively, parenteral therapy may be needed for a time. 

If there is substantial concern about cardiovascular stress (hypertension or arrhythmia) during sexual intercourse in either sex, a dose of labetalol about 2 hours before the event may well be justified (taking account of other therapy already in use). But patients taking a p-blocker long term for angina prophylaxis have shown reductions in peak heart rate during coitus from 122 to 82 beats/min. 

The authors suggested that torsade de pointes induced by intravenous amiodarone depended on heart rate during a bout of bradycardia, while that after oral amiodarone depended on increased sympathetic nervous system activity, and that therefore different electrophysiological mechanisms had been at play. However, it is by no means clear from their description of this case that that was so. They did not report plasma concentrations of amiodarone or desethylamiodarone, its active metabolite. 

Demolis JL, Funck-Brentano C, Ropers J, Ghadanfar M, Nichols DJ, JaUlon P. Influence of dofetilide on QT-interval duration and dispersion at various heart rates during exercise in humans. Circulation 1996 94(7) 1592-9. 

B. J. West, L. A. Griffin, H. J. Frederick, and R. E. Moon, The independently fractal nature of respiration and heart rate during exercise under normobaric and hyperbaric conditions. To appear in Respiratory Physiol. Neurobiol. 

V. Kariniemi and P. Ammala, Short-term variability of fetal heart rate during pregnancies with normal and insufficient placental function. Am. J. Obster. Gynecol. 139, 33-37 (1981). 

Sandvik L, Eirikssen J, Ellestad M, et al. Heart rate increase and maximal heart rate during exercise as predictors of cardiovascular mortality A 16-year follow-up smdy of 1960 healthy men. Coronary Artery Dis 1995 6 667-679. 

The exercise must be aerobic. In other words, it must not be so intense that breathing is difficult. An aerobic workout can also be achieved by monitoring breathing or heart rate. Breathing should not be labored. The exercise should not cause the heart rate to exceed 80% of the age-adjusted maximum heart rate. For a 20-year-old the maximum heart rate during exercise should not exceed 160 (i.e., 80% of 200, the maximum heart rate). 

A study in 8 healthy subjeets found that the inerease in heart rate during exereise associated with a single 40-mg dose of nicardipine was reduced by one drop of timolol 0.5% put into each eye. Systolic blood pressure was also reduced during concurrent use, but nicardipine did not cause any further reduction in the intraocular pressure reduction produced by timolol. ... 

A study in 6 healthy subjects given metoprolol 100 mg twice daily for a week found that the cimetidine 1 g daily in divided doses increased the peak plasma levels of metoprolol by 70% and the AUC by 61%, but this did not increase the effect of metoprolol on the heart rate during exercise. " Metoprolol did not affect cimetidine pharmacokinetics. ... 

Three other studies confirmed that cimetidine increased metoprolol serum levels after single or multiple doses, but none of the studies found that this interaction resulted in an increase the effect of metoprolol on the heart rate during exercise. " An isolated case describes one patient who complained of a very irregular heart beat while taking both drugs, which was much less marked when he took the two drugs separated by as much time as possible. In contrast, two other studies found that cimetidine did not affect the serum levels of a single 100-mg dose of metoprolol. ... 

A single-dose pharmacokinetic study found that quinidine 200 mg doubled the AUC and the peak plasma levels of a 20-mg dose of propranolol. Maximum heart rates during exercise were suppressed by a further 45%. A similar study by the same research group found that the AUC of propranolol was increased by about threefold by quinidine. A further study found that quinidine doubled the AUC of propranolol and halved its clearance resulting in increased beta-blockade. ... 

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