ICa density is maintained in senescence; ICa inactivation, however, is slowed. Age related differences in action potential duration and ICa inactivation were reduced by buffering intracellular Ca2+. ITO channels appear to retain normal function through the aging process but overall there is a reduced channel density. The age associated changes in these currents should contribute to prolongation of action potential duration of the early plateau phase seen in the senescent rat.

These data demonstrate that dietary hypercholesterolemia induces a "cholesterol cardiomyopathy" characterized by systolic and diastolic dysfunction. These alterations were independent of vascular disease and demonstrate a dietary link to cardiac dysfunction.