The fundamental alterations in the cardiovascular system that occur consequent to aging are of great pratical importnace to clinicians. Senescent cardic muscle has many features of prolonged tension development, impaired relaxation and diminished response to receptor-mediated inotropic interactions. We estimated left ventricular mass by 2-D echo area-length method using a high quality planimeter. Age-related increments in left ventricular mass demostrated, but left ventricular enddiastolic cavity volumes were unaffected by age. The increase in left ventricular mass observed with aging is typical of pressuer-overload hypertrophy and its stimulus may be increased afterload from senescent changes.