Figure 13. Age-associated changes in resting cardiovascular structure/function in the absence of a textbook clinical diagnosis.
Prolonged contraction of the thickened LV wall which maintains a normal ejection time in the presence of the late augmentation of aortic impedance is preserved by systolic cardiac pumping function at rest. A downside of prolonged contraction is that myocardial relaxation at the onset of diastole is relatively more incomplete in older than in younger individuals and reduces the early LV filling rate to in older vs. younger individuals. Structural changes and functional heterogeneity occurring within left ventricular tissue with aging may also contribute to this reduction in peak LV filling rate. Additional concomitant adaptations—left atrial enlargement and an enhanced atrial contribution to ventricular filling, however, compensate for the reduced early filling and maintain a normal end diastolic volume. (modified from Ref. 43)