Time course studies are critical for understanding regulatory mechanisms and temporal constraints in ectothermic animals acclimating to warmer temperatures. Therefore, we investigated the dynamics of heart rate and its neuro-humoral control in rainbow trout ( ITALIC! Onchorhynchus mykissL.) acclimating to 16°C for 39 days after being acutely warmed from 9°C. Resting heart rate was 39 beats min(...

In major prospective studies it has been reported that high heart rate at rest predicts the development of coronary heart disease (CHD) or cardiovascular disease (CVD) in men, but the mechanisms producing these relationships are unknown. Since lipoprotein levels contribute strongly to the risk of CHD and CVD, we examined the relationship of resting heart rate to plasma concentrations of high-de...

AIMS The association between resting heart rate and changes in heart rate with all-cause, cardiovascular and cancer mortality was studied among 1827 men and 2929 women, aged 40-80 years, followed for 12 years. METHODS AND RESULTS After adjustment for initial age, serum cholesterol, body mass index, systolic blood pressure, smoking and diabetes, the all-cause mortality hazard ratio was 1.7 (95...

The aim of this study was to investigate the association between average 24-hour ambulatory heart rate and all-cause mortality, while adjusting for resting clinical heart rate, cardiorespiratory fitness, occupational and leisure time physical activity as well as classical risk factors. A group of 439 middle-aged male workers free of baseline coronary heart disease from the Belgian Physical Fitn...

The autonomic components of the baroreflex control of heart rate were evaluated in conscious mongrel dogs before and after 4-6 weeks of ventricular pacing (250 beats/min). Arterial baroreflex sensitivity (BRS) was determined by the slopes of linear regression of pulse interval versus the preceding systolic arterial pressure in response to bolus injections of either phenylephrine or nitroglyceri...