Altered spatial distribution of the diastolic left ventricular pressure difference in heart failure

Abstract

Background: The left ventricle fills in early diastole because of a progressive intraventricular pressure difference (IVPD) that extends from the left atrium to the left ventricular (LV). The aim of this study was to test the hypothesis that in patients with symptomatic heart failure (HF) regardless of LV ejection fraction (EF), an increase in left atrial (LA) pressure maintains early diastolic filling because of a preserved IVPD from the left atrium to the mid left ventricle, while the IVPD from the mid left ventricle to the apex is diminished because of reduced LV suction.

Methods: One hundred fifty-one patients with HF (50 with HF with preserved EF [HFpEF; EF ≥ 50%] and 101 with HF with reduced EF [HFrEF; EF < 50%]) and 28 normal controls were prospectively enrolled. The IVPDs from the left atrium to the LV apex (total IVPD), the left atrium to the mid left ventricle (basilar IVPD), and the mid left ventricle to the apex (apical IVPD) were determined using color M-mode Doppler echocardiographic data to integrate the Euler equation. The propagation of early diastolic filling was also assessed by color M-mode Doppler.

Results: The mean LV EF was 0.63 ± 0.07 in patients with HFpEF, 0.32 ± 0.09 in those with HFrEF, and 0.64 ± 0.06 in controls. Peak early diastolic transmitral flow velocities (E) were similar among the groups, and basilar IVPDs were maintained in the HFpEF and HFrEF groups (HFpEF, 1.59 ± 0.62 mm Hg; HFrEF, 1.49 ± 0.75 mm Hg; controls, 1.80 ± 0.61 mm Hg; P = NS, analysis of variance). However, apical IVPDs were decreased in both HF groups (HFpEF, 1.18 ± 0.56 mm Hg [P < .01 vs controls]; HFrEF, 0.87 ± 0.48 mm Hg [P < .01 vs controls]; controls, 1.65 ± 0.62 mm Hg), resulting in decreased total IVPDs in patients with HF (HFpEF, 2.55 ± 0.80 mm Hg [P < .01 vs controls]; HFrEF, 2.16 ± 0.80 mm Hg [P < .01 vs controls]; controls, 3.17 ± 0.91 mm Hg). E/e' ratios were increased in patients with HF, consistent with elevated LA pressure. In patients with HF, E was correlated with basilar IVPD but not with apical IVPD, whereas propagation of the filling was correlated with the apical IVPD but not with the basilar IVPD.

Conclusions: In patients with HFpEF and those with HFrEF, apical IVPDs were reduced while basilar IVPDs were maintained by elevated LA pressure, resulting in preserved E.

Keywords: Color M-mode Doppler imaging; Heart failure; Intra–left ventricular pressure difference; Left ventricular diastolic function.

Figure 1

Left: Color M-mode Doppler imaging of transmitral flow. Rignt: Corresponding dealiased image with initial (pink) and terminal (green) propagation velocities. Because the point where the propagation velocity turns from pink to green indicates the deceleration point, the distance from mitral annulus to the deceleration point (yellow vertical arrow) was measured as an extent of propagation of the early diastolic filling.

Figure 2

Measurement of the IVPD. From the color-M mode Doppler imaging (A, top), temporal profile of the IVPD from the left atrium (LA) at the level of the mitral anulus to LV apex (A, below), from LA to mid LV (2 cm from the mitral annulus) (C), and mid LV to the apex (D) were calculated by integrating the one-dimensional Euler equation. The corresponding spatial profile of the IVPD at the peak timing of the IVPD from LA to the apex is also shown (B). From the temporal profiles of the IVPDs, the peak early diastolic IVPDs (vertical arrows) were measured for LA to the apex (black), LA to mid LV (blue), and mid LV to the apex (red), respectively. IVPD, intraventricular pressure difference.

Figure 3

Examples of the apical IVPD from mid LV to the apex (middle line), basilar IVPD from the LA to mid LV (bottom line), and the corresponding color M-mode Doppler images (Top line) are shown. In HFpEF and HFrEF, the apical IVPD from mid LV to the apex is reduced compared to the normal while the basilar IVPD from the LA to mid LV is preserved. LV, left ventricular; HFpEF, heart failure with preserved ejection fraction; HFrEF, heart failure with reduced ejection fraction. Other abbreviations are the same as Figure 2.

Figure 4

Comparisons of the total, basilar, and apical IVPD among normal controls (dense colors), HFpEF (light colors), and HFrEF (white). ^†P<0.05 vs normal controls, ^‡P<0.05 vs HFpEF. Abbreviations are the same as Figures 2 and 3.

Figure 5

A: Correlations of peak early diastolic LV filling velocity (E) to the IVPD in heart failure. B: Correlations of the deceleration point of E wave propagation from mitral annulus to the IVPD in heart failure. Abbreviations are the same as Figure 2.