Changes in Cardiac Membranes as a Function of Age with Particular Emphasis on Reactivity to Drugs

摘要: The effects of senescence on the electrophysiological behavior cardiac tissue have not been studied extensively or systematically. Yet there is a scattered number reports indicating that functioning cardiovascular system in general, and physiology myocardium particular undergo very subtle yet profound changes with increasing age. age observed both man other mammals. normal human subjects 50 to 70 years suffering from degenerative ischemia has found display such electrocardiographic alterations as prolongation P-R interval QRS complex duration (1). In group normal, healthy humans, was increase progressively birth through 60 over (2). Another study showed young adults (mean for men, 34 years, mean women, 23.5 years) had shorter left ventricular ejection times than older (3). Unan-esthetized Wistar rats reported exhibit increased heart rates, decreased blood pressures, outputs (4). Electrocardiographic incidence arrhythmias aged under control conditions (5, 6) following exercise (7).