Abstract 1958: Age Related Changes in Left Atrial Hemodynamics in Normal Adults
INTRODUCTION A marked shift in LV filling from early to late diastole occurs with normal aging and is often ascribed to changes in LV relaxation. Yet, left atrial properties also affect LV filling, and may also change with age, but have not been studied. We recorded atrial pressure-volume loops in patients with normal LV function over a wide age range undergoing percutaneous PFO closure after paradoxical embolism.
METHODS We studied 35 adults undergoing cath for PFO closure (age range=24 – 81). Baseline LV diastolic function was measured by transmitral doppler echo and tissue doppler. Just before closure, a high-fidelity pressure sensor was placed across the PFO into the LA; in a subset of patients (n=18), a 2-sensor catheter was advanced transmitrally to record simultaneous LVP and LAP. In them, LV relaxation was estimated as τ by 3-parameter fit. Balloon inflation achieved IVC occlusion; LA area by transthoracic echo served as volume surrogate in P-V loops. Elastance at end-systole (Ees) and end-reservoir phase (Eer) are slopes from IVC occlusion loops (Figure⇓).
RESULTS As expected, age was associated with rising peak A-wave velocity (p≤.001), and falling E/A (p≤.001) and tissue-doppler E/A (p≤.002). τ did not vary with age (r=.20, p=.43). At rest, age was associated with rising peak (p≤.05) and minimum (p≤.02) A-wave LAP, and a trend upward in mean LAP (p≤.07). Both Ees (p≤.01) and Eer (p≤.05) fell with age.
CONCLUSIONS Atrial contractility declines with age, despite increasing late transmitral flow, suggesting increased preload. At the same time, reduced atrial elastance at onset of LV filling (end reservoir) may potentiate the shift to later filling with age.