Abstract 12782: Effect of Aging on Left Ventricular Compliance and Distensibility in Healthy Sedentary Humans
Background: Healthy, but sedentary aging leads to marked atrophy and stiffening of the heart, with substantially reduced cardiac compliance. However, when in the aging process cardiac stiffening and atrophy occur is unknown.
Methods: Forty eight healthy, but sedentary subjects (male 23, female 25, age from 25 to 77 yrs, average 52 yrs) were recruited from the Dallas Heart Study, a population based, random sample of individuals in the Dallas community. Subjects were highly screened for comorbidities and were stratified into 4 groups according to their age; Group1: 2534 yrs, (27±3 yrs; n= 6), Group2: 35–44 yrs, (40±4 yrs; n=12), Group3: 45–54 yrs, (50±3 yrs; n=12), Group4: > 65 yrs, (70±3 yrs; n=18). All the subjects underwent invasive hemodynamic measurements with right heart catheterization to define Starling and left ventricular (LV) pressure-volume curves. LV end-diastolic volumes (EDV) were measured by thoracic echocardiography at baseline, −15 and −30 mmHg lower body negative pressure, and 2 levels of saline infusion (15 and 30 ml/kg) with simultaneous measurements of pulmonary capillary wedge pressure (PCWP).
Results: There were no differences in heart rate or cardiac output among the 4 groups at baseline. Baseline EDV were similar among Group1, 2 and 3, however, EDV in Group4 was smaller than those in Group1 and 2 (p<0.05). There were no differences in stroke volume for any given cardiac filling pressure among the 4 groups. The pressure-volume curves confirmed a substantially greater LV compliance in Group1 compared with Group2, 3 and 4, resulted in greater EDV changes with preload manipulations. Although LV chamber compliance in Group2, 3 and 4 seem to be identical, LV pressure-volume curves shifted leftward with increasing age.
Conclusion: These results suggest that LV stiffening in healthy sedentary aging seems to occur relatively early between the ages of 30–40. Thereafter, this LV stiffening is followed by age-dependent declines in LV distensibility.
- © 2010 by American Heart Association, Inc.