Visualization of the intracavitary blood flow in systemic ventricles of Fontan patients by contrast echocardiography using particle image velocimetry

<p>Abstract</p> <p>Background</p> <p>Flow patterns in univentricular hearts may have clinical value. Therefore, it is our objective to asses and characterize vortex flow patterns with Fontan circulation in comparison with healthy controls.</p> <p>Methods</p> <p>Twenty-three patients (8 Fontan and 15 normal patients) underwent echocardiography with intravenous contrast agent (Sonovue^®) administration. Dedicated software was used to perform particle image velocimetry (PIV) and to visualize intracavitary flow in the systemic ventricles of the patients. Vortex parameters including vortex depth, length, width, and sphericity index were measured. Vortex pulsatility parameters including relative strength, vortex relative strength, and vortex pulsation correlation were also measured.</p> <p>Results</p> <p>The data from this study show that it is feasible to perform particle velocimetry in Fontan patients. Vortex length (VL) was significantly lower (0.51 ± 0.09 vs 0.65 ± 0.12, <it>P </it>= 0.010) and vortex width (VW) (0.32 ± 0.06 vs 0.27 ± 0.04, <it>p </it>= 0.014), vortex pulsation correlation (VPC) (0.26 ± 0.25 vs -0.22 ± 0.87, <it>p </it>= 0.05) were significantly higher in Fontan patients. Sphericity index (SI) (1.66 ± 0.48 vs 2.42 ± 0.62, <it>p </it>= 0.005), relative strength (RS) (0.77 ± 0.33 vs 1.90 ± 0.47, <it>p </it>= 0.0001), vortex relative strength (VRS) (0.18 ± 0.13 vs 0.43 ± 0.14, <it>p </it>= 0.0001) were significantly lower in the Fontan patients group.</p> <p>Conclusions</p> <p>PIV using contrast echocardiography is feasible in Fontan patients. Fontan patients had aberrant flow patterns as compared to normal hearts in terms of position, shape and sphericity of the main vortices. The vortex from the Fontan group was consistently shorter, wider and rounder than in controls. Whether vortex characteristics are related with clinical outcome is subject to further investigation.</p

What Do We Really Know about Cognitive Inhibition? Task Demands and Inhibitory Effects across a Rang

Our study explores inhibitory control across a range of widely recognised memory and behavioural tasks. Eighty-seven never-depressed participants completed a series of tasks designed to measure inhibitory control in memory and behaviour. Specifically, a variant of the selective retrieval-practice and the Think/No-Think tasks were employed as measures of memory inhibition. The Stroop-Colour Naming and the Go/No-Go tasks were used as measures of behavioural inhibition. Participants completed all 4 tasks. Task presentation order was counterbalanced across 3 separate testing sessions for each participant. Standard inhibitory forgetting effects emerged on both memory tasks but the extent of forgetting across these tasks was not correlated. Furthermore, there was no relationship between memory inhibition tasks and either of the main behavioural inhibition measures. At a time when cognitive inhibition continues to gain acceptance as an explanatory mechanism, our study raises fundamental questions about what we actually know about inhibition and how it is affected by the processing demands of particular inhibitory tasks

Performance of the CryoValve* SG human decellularized pulmonary valve in 342 patients relative to the conventional CryoValve at a mean follow-up of four years

Objective: This study compared clinical outcomes of patients receiving CryoValve SG decellularized pulmonary valves with those of patients receiving conventionally processed CryoValve pulmonary valves. Methods: All consecutive patients undergoing Ross procedures and right ventricular outflow tract reconstructions with SG valves at 7 institutions (February 2000-November 2005) were assessed retrospectively (193 Ross procedures, 149 right ventricular outflow tract reconstructions). Patient, procedural, and outcome data were compared with those from 1246 conventional implants (665 Ross procedures, 581 right ventricular outflow tract reconstructions). Hemodynamic function was assessed at latest follow-up. Results: Follow-up was complete for 99% in SG group and 94% in conventional group, with mean follow-ups of 4.0 years (range, 0-6.7 years) for SG and 3.7 years (range, 0-6.7 years) for conventional. Five-year cumulative survivals and freedoms from adverse events were comparable between SG and conventional valves. Among patients undergoing Ross procedures, peak gradient at last follow-up was lower with SG valves (P<.01); no difference was observed in the right ventricular outflow tract reconstruction population. Pulmonary insufficiency was significantly reduced with SG valves in patients undergoing both Ross procedures (P<.01) and right ventricular outflow tract reconstructions (P<.01). Valve type was not a significant predictor of valve-related failure in propensity-adjusted analysis of either procedure. Conclusions: CryoValve SG decellularized pulmonary valves have acceptable clinical outcomes and favorably compare with conventionally processed valves. Improved hemodynamic function observed with SG valves could signify improved long-term outcomes and may be due to the decreased antigenicity of these valves. (J Thorac Cardiovasc Surg 2010; 139: 339-48