Variations of normal sinus node function in relation to age: role of autonomic influence

Ageing-dependent remodelling of ion channel and Ca2+clock genes underlying sino-atrial node pacemaking

“…With age, there are reductions in the rate of diastolic depolarization (i.e. steepness of the pacemaker potential; Alings & Bouman, 1993), intrinsic heart rate (IHR; de Marneffe et al 1986) and heart rate responses to sympathetic stimulation and vagal withdrawal (induced by atropine; Stratton et al 2003), whereas there are increases in SAN action potential duration (APD; Alings & Bouman, 1993), SAN conduction time (de Marneffe et al 1986;Alings & Bouman, 1993) and SAN recovery time (SNRT; de Marneffe et al 1986). The age-dependent decrease in IHR must be the result of a decrease in inward current or an increase in outward current during diastole.…”

Cardiorespiratory responses to exercise training after orthotopic cardiac transplantation.

“…In the final analysis, the ability of the cardiac transplant patients to attain jogging distances of between 24 and 32 km/week and power outputs of up to 170 W on the cycle ergometer implies that exercise training has considerable potential for improving the quality of life of such patients.…”

Body plethysmographic study of specific airway resistance in a sample of healthy adults

“…Higher values were only reported in the group of subjects aged <30: this may be due to the inadequate size of our sample, or it could also be the consequence of increased bronchomotor tone due to predominant parasympathetic activity in young subjects. 34 However, although very interesting from a speculative point of view, this observation does not seem significant for clinical practice.…”