Cardiovascular effects of aging - Interrelationships of aortic, left ventricular, and left atrial function

Background: Previous studies have shown that elastic properties of the aort a decrease, while left atrial dimensions, the contribution of left atrial s ystole to left ventricular filling, and left ventricular mass increase with age. In most studies, however, aortic function, and ventricular and atrial parameters were performed in different populations, and thus, the earliest manifestation of aging in the cardiovascular system is not known. The pres ent study was undertaken to define the earliest cardiovascular abnormality( ies) occurring in the cardiovascular system with age. Patients and Method: In 181 normotensive subjects (147 females and 34 males ) age 22-64 years, left ventricular mass, volumes, function and work (echoc ardiography and blood pressure), left atrial volumes and stroke volume (bip lane area-length method by echo), pulse wave velocity (PWV) (carotid to fem oral artery, Doppler), and left atrial kinetic energy were measured simulta neously: left atrial kinetic energy = 1/2 mv(2), where m = left atrial stro ke volume x 1.06 (blood specific gravity), v = transmitral A wave velocity. Regression analyses were performed to correlate all measured cardiovascula r parameters with age. Results: Pulse wave velocity (r = 0.51), left atrial kinetic energy (r = 0. 42), and A wave velocity (r = 0.38) were correlated to age, while left vent ricular mass, function and work were not. Multiple regression analysis amon g ten clinical and echocardiographic pa ra meters demonstrated that on ly a ge contributed independently to pulse wave velocity; only age and pulse wav e velocity were contributed independently to left atria I kinetic energy; a nd only age contributed independently to A wave velocity. Conclusions: The data demonstrate that age-related alterations in aortic fu nction and left atrial work (left atrial kinetic energy) can be defined pri or to changes in left ventricular structure and systolic function. Simultan eous studies of left atrial, left ventricular, and aortic function are requ ired to better understand the effect of aging on the cardiovascular system.