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An advanced ventricular assist device (VAD), which is under development in our institution, has specific features that allow changes in the axial rotor position and pump performance by intrapump pressure difference. However, performance could be influenced by the pump orientation because of the effect of gravity on the rotor position. The purpose of this study was to evaluate the effects of pump orientation on the pump performance, including pulse pressure and regurgitant flow through the pump when the pump was stopped. Bench testing of the VAD was performed on a static or pulsatile mock loop with a pneumatic device to simulate the native ventricle. The pump performance, including pressure-flow curve, pulsatility, and regurgitant flow, was evaluated at several angles, ranging from -90° (inlet pointed upward) to +90° (inlet pointed downward) at pump speeds of 2000, 2500, 3000, and 3500 rpm. The pump performance was slightly lower at +90° at all rotational speeds, compared with -90°. The pulse pressure on the pulsatile mock loop (80 bpm) was 50 mm Hg without pump support, remained at 50 mm Hg during pump support, and was not changed by orientation (-90°, 0°, and +90°). When the pump was stopped, the regurgitant flow was near 0 L/min at all angles. Pump orientation had a minor effect on pump performance, with no effect on pulse pressure or regurgitant flow when the pump was stopped. This indicates that the effect of gravity on the rotor assembly is insignificant., (© 2020 International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Background: Exercise-induced pulmonary hypertension (EIPH) may develop even at low workloads in heart failure (HF) patients. Ventricular-arterial stiffening plays an important role in the pathophysiology of HF with preserved ejection fraction (HFpEF). This study aimed to compare the response of ventricular-arterial coupling and PH during low-level exercise between HFpEF and HF with reduced EF (HFrEF)., Methods and Results: Echocardiography was performed at rest and during 10 W of bicycle exercise in HFpEF (n = 37) and HFrEF (n = 43). Load-independent contractility (end-systolic elastance [Ees], preload recruitable stroke work [PRSW], and peak power index [PWRI]), arterial afterload (arterial elastance [Ea]), and ventricular-arterial interaction (Ea/Ees) were measured with the use of a noninvasive single-beat technique. EIPH was defined as an estimated pulmonary arterial systolic pressure (PASP) of ≥50 mm Hg at 10 W of exercise. PASP was significantly increased during 10 W of exercise in both HF types, and ~50% of HFpEF patients developed EIPH. Arterial afterload was increased significantly during exercise in both groups. HFrEF and HFpEF patients showed a significant increase in LV contractility assessed by Ees, PRSW, and PWRI during exercise. Although Ea/Ees ratio decreased significantly in HFrEF, reduction in Ea/Ees was attenuated because of blunted Ees increases in patients with HFpEF compared with HFrEF., Conclusions: Even at low-level exercise, ~50% of HFpEF patients developed EIPH. Reduction in Ea/Ees was attenuated owing to less Ees increase in HFpEF compared with HFrEF. Further studies are needed to elucidate the association between ventricular-arterial coupling and EIPH in HFpEF., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Real-time three-dimensional echocardiographic (3DE) imaging usually requires multibeat acquisition to maintain high temporal and spatial resolution for full-volume data sets. However, this procedure generates stitch artifacts in patients with irregular heartbeats; thus, one-beat acquisition might be useful. The aim of this study was to compare the efficacy of using new-generation one-beat full-volume acquisition for measuring left ventricular (LV) mechanical parameters with that of four-beat acquisition., Methods: In protocol 1, 34 patients who had undergone both cardiac magnetic resonance and 3DE imaging on the same day were prospectively enrolled. In protocol 2, 115 patients in sinus rhythm who had undergone 3DE examinations were retrospectively enrolled. LV volume, ejection faction, and global strain were measured using one-beat and four-beat 3DE data sets. In protocol 3, 26 patients with atrial fibrillation who had acquisition of consecutive one-beat full-volume data sets were retrospectively enrolled, and it was determined whether the LV parameters in the index beat were correlated with corresponding average values obtained from multiple one-beat acquisitions., Results: In protocol 1, the correlations between LV volumes and LV ejection fraction between cardiac magnetic resonance and 3DE imaging with one-beat acquisition were excellent (r = 0.91-0.93). In protocol 2, correlations were also excellent (r = 0.94-0.99), and there were no significant differences in volume rate, LV volumes, LV ejection fraction, and global strain parameters between one-beat and four-beat acquisition data sets. In protocol 3, correlations were excellent (r = 0.94-0.99) between LV parameters from the index beat and corresponding average values., Conclusions: Three-dimensional echocardiographic full-volume data sets with one-beat acquisition not only maintained volume rate but also provided LV mechanical parameter values similar to those obtained using multibeat acquisition. Using one-beat acquisition for patients with atrial fibrillation expands its clinical applicability., (Copyright © 2016 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.)

Aims: Cardiac magnetic resonance (CMR) feature tracking (FT) with steady-state free precession (SSFP) has advantages over traditional myocardial tagging to analyse left ventricular (LV) strain. However, direct comparisons of CMRFT and 2D/3D echocardiography speckle tracking (2/3DEST) for measurement of LV strain are limited. The aim of this study was to investigate the feasibility and reliability of CMRFT and 2D/3DEST for measurement of global LV strain., Methods and Results: We enrolled 106 patients who agreed to undergo both CMR and 2D/3DE on the same day. SSFP images at multiple short-axis and three apical views were acquired. 2DE images from three levels of short-axis, three apical views, and 3D full-volume datasets were also acquired. Strain data were expressed as absolute values. Feasibility was highest in CMRFT, followed by 2DEST and 3DEST. Analysis time was shortest in 3DEST, followed by CMRFT and 2DEST. There was good global longitudinal strain (GLS) correlation between CMRFT and 2D/3DEST (r = 0.83 and 0.87, respectively) with the limit of agreement (LOA) ranged from ±3.6 to ±4.9%. Excellent global circumferential strain (GCS) correlation between CMRFT and 2D/3DEST was observed (r = 0.90 and 0.88) with LOA of ±6.8-8.5%. Global radial strain showed fair correlations (r = 0.69 and 0.82, respectively) with LOA ranged from ±12.4 to ±16.3%. CMRFT GCS showed least observer variability with highest intra-class correlation., Conclusion: Although not interchangeable, the high GLS and GCS correlation between CMRFT and 2D/3DEST makes CMRFT a useful modality for quantification of global LV strain in patients, especially those with suboptimal echo image quality., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)