Substituted tetrabenzocyclophanes as mesogenic units of new polycondensates exhibiting columnar mesophases

Recently a new family of flexible mesogens has been described namely hexa-alkylated derivatives of cyclotetraveratrylene. We have functionalized these compounds, obtaining monofunctionalized and bifunctionalized derivatives with heptyloxy side groups. A model dimer and polycondensates were synthesized. Calorimetric data as well as optical data prove that they exhibit columnar meso-phases. At this point it is not clear whether the conformation of the mesogenic units in the mesophase is tetragonal pyramidic with all of the mesogens being extended in one direction or discotic because of the high internal flexibility of the mesogenic core. The synthesis of the model dimer and the polycondensates as well as the calorimetric and optical data are the subject of this article

Clinical response to either biventrcular or left ventricular only pacing for cardiac resynchronization therapy: results of the double-blind randomized BLEFT-HF study. Presentation European Congress of Cardiology 2008

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A randomized double-blind comparison of biventricular versus left ventricular stimulation for cardiac resynchronization therapy: The Biventricular versus Left Univentricular Pacing with ICD Back-up in Heart Failure Patients (B-LEFT HF) trial

Background: Biventricular (BiV) stimulation is the preferred means of delivering cardiac resynchronization therapy (CRT), although left ventricular (LV)-only stimulation might be as safe and effective. B-LEFT HF is a prospective, multicenter, randomized, double-blind study aimed to examine whether LV-only is noninferior to BiV pacing regarding clinical and echocardiographic responses. Methods: B-LEFT HF randomly assigned 176 CRT-D recipients, in New York Heart Association class III or IV, with an LV ejection fraction ≤35% and QRS ≥130 milliseconds, to a BiV (n = 90) versus LV (n = 86) stimulation group. Clinical status and echocardiograms were analyzed at baseline and 6 months after CRT-D implant to test the noninferiority of LV-only compared with BiV stimulation. Results: The proportion of responders was in line with current literature on CRT, with improvement in heart failure composite score in 76.2% and 74.7% of patients in BiV and LV groups, respectively. Comparing LV versus BiV pacing, the small differences in response rates and corresponding 95% CI indicated that LV pacing was noninferior to BiV pacing for a series of response criteria (combination of improvement in New York Heart Association and reverse remodeling, improvement in heart failure composite score, reduction in LV end-systolic volume of at least 10%), both at intention-to-treat and at per-protocol analysis. Conclusions: Left ventricular-only pacing is noninferior to BiV pacing in a 6-month follow-up with regard to clinical and echocardiographic responses. Left ventricular pacing may be considered as a clinical alternative option to BiV pacing. © 2010 Mosby, Inc. All rights reserved

First prospective, multi-centre clinical experience with a novel left ventricular quadripolar lead.

Abstract AIMS: Cardiac resynchronization therapy (CRT) is sometimes complicated by elevated pacing thresholds and phrenic nerve stimulation (PNS), both of which may require that the coronary sinus lead be repositioned. The purpose of this study was to evaluate the performance of a novel quadripolar electrode lead and cardiac resynchronization therapy-defibrillator (CRT-D) device that enables electrical repositioning, potentially obviating a lead reposition procedure. METHODS AND RESULTS: Patients indicated for CRT were enrolled and received a quadripolar electrode lead and CRT-D device (Quartetmodel 1458Q and Promote Q; St Jude Medical, Sylmar, CA, USA). Electrical data, and the presence of PNS during pacing from each left ventricular (LV) configuration, were documented at pre-hospital discharge and at 1 month. Seventy-five patients were enrolled and 71 were successfully implanted with a Quartetlead. Electrical measurements were stable over the follow-up period. Ninety-seven per cent (64 of 66) of patients had one or more programmable configurations with a threshold < 2.5 V and no PNS vs. 86% (57 of 66) if only conventional bipolar configurations were considered. Physicians were able to use the increased programming options to manage threshold changes and PNS. CONCLUSION: The new quadripolar electrode LV lead provides more programming options to address common problems faced when managing CRT patients. Electrical measurements from new vectors are comparable with conventional configurations. Furthermore, 11% of patients in the study suffered PNS on all conventional bipolar vector

First prospective, multi-centre clinical experience with a novel left ventricular quadripolar lead.

Abstract AIMS: Cardiac resynchronization therapy (CRT) is sometimes complicated by elevated pacing thresholds and phrenic nerve stimulation (PNS), both of which may require that the coronary sinus lead be repositioned. The purpose of this study was to evaluate the performance of a novel quadripolar electrode lead and cardiac resynchronization therapy-defibrillator (CRT-D) device that enables electrical repositioning, potentially obviating a lead reposition procedure. METHODS AND RESULTS: Patients indicated for CRT were enrolled and received a quadripolar electrode lead and CRT-D device (Quartetmodel 1458Q and Promote Q; St Jude Medical, Sylmar, CA, USA). Electrical data, and the presence of PNS during pacing from each left ventricular (LV) configuration, were documented at pre-hospital discharge and at 1 month. Seventy-five patients were enrolled and 71 were successfully implanted with a Quartetlead. Electrical measurements were stable over the follow-up period. Ninety-seven per cent (64 of 66) of patients had one or more programmable configurations with a threshold < 2.5 V and no PNS vs. 86% (57 of 66) if only conventional bipolar configurations were considered. Physicians were able to use the increased programming options to manage threshold changes and PNS. CONCLUSION: The new quadripolar electrode LV lead provides more programming options to address common problems faced when managing CRT patients. Electrical measurements from new vectors are comparable with conventional configurations. Furthermore, 11% of patients in the study suffered PNS on all conventional bipolar vector