Cardiac resynchronization therapy during rest and exercise: comparison of two optimization methods

Optimal exercise programming of cardiac resynchronization therapy (CRT) devices is unknown. We aimed to: (i) investigate variations in optimal atrioventricular (AV) and interventricular (VV) delays from rest to exercise, assessed by both echocardiography and an automated intracardiac electrogram (IEGM) method; (ii) evaluate the acute haemodynamic impact of CRT optimization performed during exercise

Sodium lauryl ether sulfate (SLES) degradation by nitrate-reducing bacteria

The online version of this article (doi:10.1007/s00253-017-8212-x) contains supplementary material, which is available to authorized users.The surfactant sodium lauryl ether sulfate (SLES) is widely used in the composition of detergents and frequently ends up in wastewater treatment plants (WWTPs). While aerobic SLES degradation is well studied, little is known about the fate of this compound in anoxic environments, such as denitrification tanks of WWTPs, nor about the bacteria involved in the anoxic biodegradation. Here, we used SLES as sole carbon and energy source, at concentrations ranging from 50 to 1000 mg L1, to enrich and isolate nitrate-reducing bacteria from activated sludge of a WWTP with the anaerobic-anoxic-oxic (A2/O) concept. In the 50 mg L1 enrichment, Comamonas (50%), Pseudomonas (24%), and Alicycliphilus (12%) were present at higher relative abundance, while Pseudomonas (53%) became dominant in the 1000 mg L1 enrichment. Aeromonas hydrophila strain S7, Pseudomonas stutzeri strain S8, and Pseudomonas nitroreducens strain S11 were isolated from the enriched cultures. Under denitrifying conditions, strains S8 and S11 degraded 500 mg L1 SLES in less than 1 day, while strain S7 required more than 6 days. Strains S8 and S11 also showed a remarkable resistance to SLES, being able to grow and reduce nitrate with SLES concentrations up to 40 g L1. Strain S11 turned out to be the best anoxic SLES degrader, degrading up to 41% of 500 mg L1. The comparison between SLES anoxic and oxic degradation by strain S11 revealed differences in SLES cleavage, degradation, and sulfate accumulation; both ester and ether cleavage were probably employed in SLES anoxic degradation by strain S11.This research was supported by the Spanish Ministry of Education and Science (contract project CTQ2007-64324 and 447 CONSOLIDER-CSD 2007-00055). The Regional Government of Castilla y Leon (Ref. GR76) is also gratefully acknowledged. MRD is supported by the WIMEK graduate school (project BAdaptive capacity and functionality of multi-trophic aquatic ecosystems^). AJMS is supported by the Gravitation grant (project 024.002.002) of the Netherlands Ministry of Education, Culture and Science and the Netherlands Science Foundation (NWO). AJMS and AJC are supported by an European ResearchCouncil (ERC) Grant (Project 323009).Thisstudywassupported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. This study was alsosupportedbythePortugueseFoundationforScienceandTechnology (FCT) under the scope of the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). Joana Alves from University of Minho (Portugal) is acknowledged for support with the molecular techniques.info:eu-repo/semantics/publishedVersio

Changes in global longitudinal strain during rest and exercise in patients treated with cardiac resynchronization therapy.

Relatively few data have been reported on prospective changes in global longitudinal strain (GLS) following cardiac resynchronization therapy (CRT), and none are available on GLS during physical exercise. We investigated the effects of CRT on GLS, assessed by speckle tracking two-dimensional (2D) echocardiography, at rest and during exercise after a mid-term follow-up. Twenty consecutive CRT patients (45% ischaemic) were assessed prospectively by speckle tracking 2D echocardiography before implant (at rest) and at mid-term follow-up (during rest and bicycle exercise). GLS, septum and lateral wall longitudinal strain, left ventricular ejection fraction (LVEF), and conventional functional variables were evaluated at baseline and follow-up. All patients completed the study protocol at rest. Exercise images were available in 90% of the patients. At follow-up, GLS improved at rest from -7\ub71 \ub1 2\ub76% to -9\ub71 \ub1 4\ub75% (P<0\ub701), with a further increase to -11 \ub1 5\ub71% during exercise (P<0\ub7001). Longitudinal strain increased at rest both in the septum and in the lateral wall, with an additional increase during exercise in the lateral wall (P<0\ub705). GLS correlated with LVEF both at rest (r = -0\ub755 and r = -0\ub791 at baseline and 3 months, respectively; P<0\ub705) and during exercise (r = -0\ub789, P<0\ub705). Improvement in GLS during rest and exercise can be observed in CRT patients at mid-term follow-up and seems to correlate with changes in LVEF. GLS may be a valuable method to assess left ventricular function during rest and exercise

Changes in global longitudinal strain during rest and exercise in patients treated with cardiac resynchronization therapy.

Relatively few data have been reported on prospective changes in global longitudinal strain (GLS) following cardiac resynchronization therapy (CRT), and none are available on GLS during physical exercise. We investigated the effects of CRT on GLS, assessed by speckle tracking two-dimensional (2D) echocardiography, at rest and during exercise after a mid-term follow-up. Twenty consecutive CRT patients (45% ischaemic) were assessed prospectively by speckle tracking 2D echocardiography before implant (at rest) and at mid-term follow-up (during rest and bicycle exercise). GLS, septum and lateral wall longitudinal strain, left ventricular ejection fraction (LVEF), and conventional functional variables were evaluated at baseline and follow-up. All patients completed the study protocol at rest. Exercise images were available in 90% of the patients. At follow-up, GLS improved at rest from -7·1 ± 2·6% to -9·1 ± 4·5% (P<0·01), with a further increase to -11 ± 5·1% during exercise (P<0·001). Longitudinal strain increased at rest both in the septum and in the lateral wall, with an additional increase during exercise in the lateral wall (P<0·05). GLS correlated with LVEF both at rest (r = -0·55 and r = -0·91 at baseline and 3 months, respectively; P<0·05) and during exercise (r = -0·89, P<0·05). Improvement in GLS during rest and exercise can be observed in CRT patients at mid-term follow-up and seems to correlate with changes in LVEF. GLS may be a valuable method to assess left ventricular function during rest and exercise

Placebo effect of pacemaker implantation in obstructive hypertrophic cardiomyopathy. PIC Study Group. Pacing In Cardiomyopathy

This study evaluated a possible placebo effect by pacemaker implantation. The study design was a 3-month multicenter, double-blind, randomized cross-over study to compare the effects of atrioventricular (AV) synchronous pacing with an optimal AV delay to inactive pacing in patients with obstructive hypertrophic cardiomyopathy (HC). Quality of life and left ventricular (LV) outflow tract obstruction were evaluated after the first study period in 40 patients assigned to inactive pacing. Data were compared with the corresponding results among the 41 subjects assigned to a first study period of active pacing. During inactive pacing, there was a significant improvement in perceived chest pain, dyspnea, and palpitations. Moreover, LV outflow tract gradient decreased from 71 +/- 32 mm Hg to 52 +/- 34 mm Hg (p = 0.04). In patients assigned to active pacing the reduction of the gradient was significantly more pronounced (70 +/- 24 mm Hg to 33 +/- 27 mm Hg; p &lt;0.0001). The difference in gradient reduction between the groups was highly significant (p &lt;0.00001). In the group assigned to active pacing there was also significant improvement in perceived symptoms as well as in alertness, the ability to be self-autonomous, and strenuous physical exercise. The improvements in the latter were significantly greater in those paced actively compared with patients paced inactively, whereas the changes in perceived symptoms did not differ between groups. In conclusion, pacemaker implantation had a placebo effect on objective and subjective parameters in this group of patients with obstructive HC