Accession Number : AD0654701

Title :   CARDIAC ARRHYTHMIA IN THE AGING MALE RAT,

Corporate Author : NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF

Personal Author(s) : Jones,D. C. ; Osborn,G. K. ; Kimeldorf,D. J.

Report Date : 29 MAY 1967

Pagination or Media Count : 26

Abstract : Groups of male rats (median lifespan, 23 months) were subjected to one hour of exercise on a treadmill (15% grade) at 3, 10, 16, 22, and 28 months of age. Records of ventricular electric potentials taken at intervals before, during, and after the period of exercise were examined for evidence of cardiac arrhythmia. The incidence of animals with arrhythmic sequences varied with age: negligible at three and at ten months (4%), 15% (8/53) at 16 months, 68% (45/66) at 22, and 86% (6/7) at 28 months of age. More rats showed arrhythmia before exercise or after a period of post-exercise rest, than during the exercise itself. The predominant arrhythmic sequence consisted of a premature wave followed by a compensatory pause, but recordings indicative of sinus arrhythmia and of conduction defects (block) were also seen. (Author)

Descriptors :   (*ARRHYTHMIA, *AGING(PHYSIOLOGY)), HEART, DISEASES, EXERCISE(PHYSIOLOGY), ELECTROCARDIOGRAPHY, RATS

Subject Categories : Anatomy and Physiology
      Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE