We attempted to clarify myocardial telomere dynamics using samples from 530 autopsied patients using Southern blot analysis. Overall regression analysis demonstrated yearly telomere reduction rate of 20 base pairs in the myocardium. There was a significant correlation between myocardial telomere and aging. Moreover, regression analyses of telomere and heart weight yielded a telomere reduction rate of 3 base pairs per gram and a small but significant correlation between telomere reduction and heart weight was demonstrated. Hearts of autopsied patients who had died of heart disease were significantly heavier than those of patients who had died of cancer or other diseases and heart disease was significantly more correlated with myocardial telomere shortening than cancer or other diseases. Here we show that telomeres in myocardial tissue become shortened with aging and heart disease and that heart disease was associated with a gain of heart weight and telomere shortening in the myocardium.