The SALT-Readout ASIC for Silicon Strip Sensors of Upstream Tracker in the Upgraded LHCb Experiment.

SALT, a new dedicated readout Application Specific Integrated Circuit (ASIC) for the Upstream Tracker, a new silicon detector in the Large Hadron Collider beauty (LHCb) experiment, has been designed and developed. It is a 128-channel chip using an innovative architecture comprising a low-power analogue front-end with fast pulse shaping and a 40 MSps 6-bit Analog-to-Digital Converter (ADC) in each channel, followed by a Digital Signal Processing (DSP) block performing pedestal and Mean Common Mode (MCM) subtraction and zero suppression. The prototypes of SALT were fabricated and tested, confirming the full chip functionality and fulfilling the specifications. A signal-to-noise ratio of about 20 is achieved for a silicon sensor with a 12 pF input capacitance. In this paper, the SALT architecture and measurements of the chip performance are presented.

Atrial fibrillation in patients with Wolff-Parkinson-White syndrome: role of pulmonary veins.

AIM: We aimed to characterize electrophysiological properties of pulmonary veins (PVs) in patients with Wolff-Parkinson-White (WPW) syndrome and atrial fibrillation (AF), and to compare them to those in patients with WPW without AF. METHODS AND RESULTS: A total of 31 patients (mean age 40 ± 15 years, 23 males) with WPW were recruited: 16 patients with (AF group) and 15 without (controls) a history of AF. The basic electrophysiological (EPS) and echocardiographic data were not different between the 2 groups. Effective refractory periods (ERPs) of PVs were significantly shorter in the AF group compared to controls: left superior (LS) PV ERP 185±29 versus 230 ± 24 ms, P = 0.001; left inferior PV ERP 198 ± 25 versus 219 ± 26 ms, P = 0.04; right superior (RS) PV ERP 207 ± 25 versus 236 ± 19 ms, P = 0.001; right inferior PV ERP 208 ± 30 versus 240 ± 19 ms, P = 0.003. Maximal veno-atrial conduction delay (i.e., the maximal prolongation of interval from stimulus delivered at PV ostia to proximal coronary sinus after extrastimulus compared to the basic drive cycle) was longer in the AF group when pacing from LSPV (69.3 ± 37.9 vs 32.6 ± 16.1 ms, P = 0.01) and RSPV (74.1 ± 25.9 vs 50.2 ± 26.5 ms, P = 0.04). During EPS, AF was induced more often in the AF group (n = 7) compared to controls (n = 1; P = 0.04). Follow-up revealed that AF recurred in 3 patients in the AF group and none of the controls. CONCLUSION: Patients with WPW syndrome and AF have shorter ERPs of PVs and greater maximal veno-atrial conduction delay compared to patients with WPW without AF. These findings suggest a potential role of PVs in the development of AF in patients with WPW.

Real-Life Inter-Rater Variability of the PRAETORIAN Score Values.

(1) Background: The PRAETORIAN score is a tool developed for postoperative evaluation of the position of subcutaneous implantable cardioverter-defibrillator systems. The aim of our study was to evaluate the real-life inter-rater variability of the PRAETORIAN score, based on chest radiographs of S-ICD patients reviewed by independent clinical raters. (2) Methods: Postoperative chest X-rays of patients that underwent S-ICD implantation were evaluated by five clinical raters who gave values of the PRAETORIAN score. Ratings were then compared in a fully crossed manner to determine the inter-rater variability of the attributed scores. (3) Results: In total, 87 patients were included in the study. In the case of the most important final risk category of the PRAETORIAN score, the mean Light's kappa was 0.804, the Fleiss' kappa was 0.249, and the intraclass correlation was 0.38. The final risk category was identically determined by all five raters in 75.86% of patients, by four raters in 14.94%, and by three raters in 9.20% of patients. (4) Conclusions: The overall inter-rater variability of the PRAETORIAN score in a group of electrophysiologists experienced in S-ICD implantation, yet previously naive to the PRAETORIAN score, and self-trained in its utilization, was only modest in our study. Appropriate use of the score might require training of clinical raters.

Influence of QRS duration and axis on response to cardiac resynchronization therapy in chronic heart failure with reduced left ventricular ejection fraction: A single center study including patients with left bundle branch block.

BACKGROUND: The aim of the study was to evaluate QRS duration and axis as predictors of response to cardiac resynchronization therapy (CRT) in order to reduce the proportion of non-responders. METHODS: Retrospective single-center study including 42 CRT recipients, with left bundle branch block (LBBB), left ventricular ejection fraction (LVEF) < 40%, in New York Heart Association (NYHA) class ≥ II. Response to CRT was declared as NYHA class improvement ≥ 1 (symptomatic) and LVEF improvement by ≥ 10% (echocardiographic) > 6 months post implantation. RESULTS: Symptomatic responders had longer pre- (172.3 ± 17.9 vs. 159.0 ± 18.3 ms; p = 0.027) and postimplantation (157.2 ± 24.1 vs. 136.7 ± 23.2 ms; p = 0.009) QRS duration. Preimplantation QRS < 150 ms predicted poor response (odds ratio [OR] for response vs. lack of response 0.04; 95% confidence interval [CI] 0.001-0.74). Predictors of symptomatic response included: postimplantation QRS > 160 ms (OR 7.2; 95% CI 1.24-41.94), longer QRS duration before (OR for a 1 ms increase 1.04, 95% CI 1.00-1.08) and post implantation (OR for a 1 ms increase 1.04; 95% CI 1.01-1.07). Area under the curve (AUC) for pre- and postimplantation QRS duration was 0.672 (95% CI 0.51-0.84) and 0.727 (95% CI 0.57-0.89), respectively, with cut-off points of 178.5 ms and 157 ms. For post implantation QRS axis, AUC was 0.689 (95% CI 0.53-0.85), with cut-off points of -60.5° or -38.5°. Preimplantation QRS axis was the only predictor of echocardiographic response (OR 0.98; 95% CI 0.96-1.00), with AUC of 0.693 (95% CI 0.54-0.85) and a threshold of -36°. CONCLUSIONS: Marked pre- and postimplantation QRS prolongation and preimplantation negative QRS axis deviation are moderate predictors of response to CRT.

[Cardiac resynchronisation therapy as a cause of the electrical storm]. / Stymulacja resynchronizujaca jako czynnik przyczynowy burzy elektrycznej.

We report a case of young patient with dilated cardiomyopathy and implanted cardioverter-defibrillator in which resynchronisation therapy (CRT-D) induced an electrical storm. One month after implantation of a cardiac resynchronisation pacemaker (CRT-P) the patient suffered from ventricular tachycardia with poor haemodynamic status and was treated by implantation of a CRT-D with a Y adaptor. After replacement of the CRT-D due to Y adaptor damage (new device without a Y adaptor) we observed an electrical storm during ventricular pacing (biventricular, right and left ventricular pacing respectively). Changing pacing mode from DDDR to AAIR resolved ventricular tachycardias in that patient.

Plasma visfatin/nicotinamide phosphoribosyltransferase (visfatin/NAMPT) concentration in elderly subjects with metabolic syndrome.

INTRODUCTION: Visceral adipose tissue is the main source of circulating proinflammatory adipokine, visfatin/nicotinamide phosphoribosyltransferase (visfatin/NAMPT), whose role in the pathogenesis of metabolic syndrome (MS) components such as hypertension and carbohydrate and lipid disturbances is still uncertain, due to commonly used low specific C-terminal immunoassays to determine visfatin/NAMPT levels. OBJECTIVES: The aim of the study was to assess the association between the occurrence of MS components and circulating visfatin/NAMPT levels in elderly popula tion. PATIENTS AND METHODS: The analysis included 2174 elderly participants of the PolSenior study without heart failure, severe chronic kidney disease, cancer, and malnutrition. MS was defined according to the modified International Diabetes Federation criteria. Plasma visfatin/NAMPT concentrations were measured by a highly specific enzyme-linked immunosorbent assay. Additionally, high-sensitivity C-reactive protein (hsCRP), interleukin 6 (IL-6), and insulin levels were assessed, and the homeostasis model assessment for insulin resistance was calculated. RESULTS: Women were diagnosed with MS more often than men (71.2% vs 56.8%; P <0.001) and had a greater prevalence of all MS components except for type 2 diabetes. Women with MS had higher concentrations of hsCRP and IL-6 than those without MS. Visfatin/NAMPT concentrations were higher in women with MS than in those without MS (1.06 ng/ml [0.65-1.87] vs 0.85 ng/ml [0.54-1.40]; P <0.001), but no differences were observed in men (0.97 ng/ml [0.59-1.61] vs 0.90 ng/ml [0.56-1.60], respectively; P = 0.5). In women, there was a stronger association between the number of components of MS and increased plasma visfatin/NAMPT levels than in men. CONCLUSIONS: Plasma visfatin/NAMPT levels are increased only in elderly women with MS. It is difficult to distinguish the components of MS specifically associated wit h increased visfatin/NAMPT levels.

[Cardiac revascularisation in a high-risk patient--case report]. / Etapowa rewaskularyzacja serca u chorego wysokiego ryzyka.

A case of a patient with left main stem stenosis and significant stenosis in the other coronary arteries is presented. The patient was disqualified from coronary artery bypass grafting (CABG) because of many surgical risk factors and underwent successful coronary angioplasty. Three months later the patient returned to the hospital because of unstable angina. Control coronary angiography revealed in-stent restenosis. The patient underwent CABG and drug-eluting stent implantation with good clinical result.

Left ventricle systolic volume in vasovagal syncope patients.

One of the hypotheses put forward concerning the mechanism of vasovagal syncope is that the vagal afferent fibres are activated during vigorous contractions against a partly empty left ventricle. The aim of the study was to confirm this hypothesis by using 2D echocardiography during a head-up tilt test. The study was carried out on 39 patients (17 male, 22 female, age range 21-64 years), all with a history of recurrent syncope. The patients were examined using a 2D echo to measure the end-diastolic and end-systolic volume before the head-up tilt test after the Westminster protocol (45 min/60 grade) and every five minutes after tilting. T patients during head-up tilt test had a positive response and 32 proved negative. A reduction of both the end-diastolic and end-systolic volumes of the left ventricle was noticed. There was no significant difference in the degree of ejection fraction reduction. The difference in ejection fraction reduction between the two groups was similarly non-significant. It was also noticed that the patients with a positive response had more vigorous contractions than those with a negative test. The decision was therefore taken to use a different parameter for the left ventricle contraction, namely the LV posterior wall slope. As this parameter is partly dependent on time, its use in confirming the extremely vigorous nature of the contractions was considered appropriate. Only 6 patients were tested using this parameter. A tendency towards greater left ventricle posterior wall slope values, both before and during tilting was noticed in the group of patients with vasovagal reaction. Our data shows that vigorous contraction is probably less responsible for vasovagal syncope release than left ventricle volume reduction.

Influence of cardiac resynchronization therapy on oxidative stress markers in patients with chronic heart failure.

BACKGROUND: The aim of the study was to assess changes of substances of oxidative stress in patients treated with cardiac resynchronization therapy (CRT). METHODS: The study comprised 51 patients with median age of 66 years. The presence, severity, and changes of oxidative stress during CRT were assessed and expressed as malondialdehyde (MDA) concentration in plasma or in red blood cells. Antioxidant activity was assessed by the activity of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in red blood cells. The concentration and activities were analyzed directly prior to implantation, 2-5 days after the procedure and after 6 months. Follow-up (6 months) included clinical, echocardiographic and implanted device assessments. RESULTS: During the follow-up, 14% patients died. The median percentage of biventricular pacing was 99.29%. After 6 months 88% of patients improved NYHA, 12% remained as non-responders. Left ventricular ejection fraction increased from median 21.5% to 29% (p < 0.05). Left ventricular end-diastolic diameter decreased significantly from a median of 69.5 mm to 63 mm (p < 0.05). After a 6-month study, MDA plasma concentration and the activity levels of each antioxidant enzymes (CAT, SOD, GPx) showed a statistically significant reduction (p < 0.05). Changes concerning MDA concentrations in red blood cells remained statistically insignificant. CONCLUSIONS: Resynchronization effect oxidative stress by reducing plasma concentration of MDA, CAT, SOD and GPX.