Decreased left ventricular distensibility in response to postural change in older patients with heart failure and preserved ejection fraction

Abstract

Most elderly persons with heart failure have a preserved left ventricular (LV) ejection fraction (HFPEF). The pathophysiology of this disorder is not well understood, and there are conflicting data regarding the role of decreased LV distensibility. To assess LV distensibility over a range of preload conditions while minimizing the large, confounding changes in contractility, afterload, and heart rate characteristic of exercise, we measured LV end-diastolic volume (EDV), stroke volume (SV), and cardiac output (CO) using two-dimensional echocardiography in 48 elderly (mean age, 69 yr) HFPEF patients and 25 healthy age-matched controls during quiet supine rest, 45 degrees head-up tilt (HUT), and 45 degrees head-down tilt (HDT). As a result, when compared with controls, HFPEF patients had reduced percent changes in EDV (-7 +/- 2 vs. -17 +/- 2%; P = 0.003), SV (-7 +/- 3 vs. -27 +/- 2%; P = 0.003), and CO (-6 +/- 4 vs. -34 +/- 4%; P = 0.001) during the transition from supine to HUT. HFPEF also had reduced percent changes in EDV (8 +/- 2 vs. 15 +/- 2%; P = 0.02), SV (11 +/- 3 vs. 21 +/- 3%; P = 0.002), and CO (1 +/- 4 vs. 12 +/- 4%; P = 0.04) during the transition from HUT to HDT. In conclusion, HFNEF patients have reduced LV distensibility in response to postural change, resulting in blunted EDV, SV, and CO. This provides further support for the hypothesis that a blunted Frank-Starling mechanism may contribute to the pathophysiology of HFPEF.

Fig. 1.

Plot of mean values ± SE. End-diastolic volume (A), end-systolic volume (B), stroke volume (C), and cardiac output (D) at each posture for heart failure with preserved ejection fraction [HFPEF (solid lines) vs. controls (dashed lines)] are shown. *P < 0.05 for intergroup comparisons.

Fig. 2.

Percent change mean data ± SE in end-diastolic volume (EDV; A), end-systolic volume (ESV; B), stroke volume (SV; C), and cardiac output (CO; D) in response to postural changes supine to head-up tilt (HUT) and of HUT to head-down tilt (HDT) for HFPEF (black bars) and controls (white bars) are shown. *P < 0.05 between groups.