Optimization of the atrioventricular delay in conduction system pacing.

INTRODUCTION: In patients receiving conduction system pacing (CSP), it is not well established how to program the sensed atrioventricular delay (sAVD), with respect to the type of capture obtained (selective, nonselective His-bundle [HB] capture or left bundle branch [LBB] capture). The aim of this study was to acutely assess the effectiveness of an electrophysiology (EP)-guided method for sAVD optimization by comparing it with the echocardiogram-guided optimization. METHODS AND RESULTS: Consecutive patients undergoing HB or LBB pacing were enrolled. The EP-guided sAVD was defined as the sAVD leading to a PR interval of 150 ms on surface electrocardiogram (ECG). In HB pacing patients, EP-guided sAVD was obtained subtracting the time from the onset of the P wave on ECG to the local atrial electrogram (EGM) recorded by the atrial lead (right atrial sensing latency, RASL) and the His-ventricular interval from 150 ms; in LBB pacing patients, subtracting RASL from 150 ms. Transmitral flow assessment by pulsed wave Doppler was used to find the echo-optimized sAVD by a modified iterative method. The discordance between the EP-guided and the echo-optimized sAVD was recorded. RESULTS: Seventy-one patients were enrolled: 12 with selective, 32 nonselective HB capture, and 27 LBB capture. Overall, the rate of concordance between the EP-guided and the echo-optimized sAVD was 71.8%, with no significant differences between the three groups. CONCLUSION: In CSP patients, an optimal sAVD can be programmed, in more than 70% of cases, considering only simple EGM intervals to obtain a physiological PR interval on surface ECG.

Effects of closed-loop stimulation vs. DDD pacing on haemodynamic variations and occurrence of syncope induced by head-up tilt test in older patients with refractory cardioinhibitory vasovagal syncope: the Tilt test-Induced REsponse in Closed-loop Stimulation multicentre, prospective, single blind, randomized study.

Aims: Closed-loop stimulation (CLS) seemed promising in preventing the recurrence of vasovagal syncope (VVS) in patients with a cardioinhibitory response to head-up tilt test (HUTT) compared with conventional pacing. We hypothesized that the better results of this algorithm are due to its quick reaction in high-rate pacing delivered in the early phase of vasovagal reflex, which increase the cardiac output and the blood pressure preventing loss of consciousness. Methods and results: This prospective, randomized, single-blind, multicentre study was designed as an intra-patient comparison and enrolled 30 patients (age 62.2 ± 13.5 years, males 60.0%) with cardioinhibitory VVS, carrying a dual-chamber pacemaker incorporating CLS algorithm. Two HUTTs were performed one week apart: one during DDD-CLS 60-130/min pacing and the other during DDD 60/min pacing; patients were randomly and blindly assigned to two groups: in one the first HUTT was performed in DDD-CLS (n = 15), in the other in DDD (n = 15). Occurrence of syncope and haemodynamic variations induced by HUTT was recorded during the tests. Compared with DDD, DDD-CLS significantly reduced the occurrence of syncope induced by HUTT (30.0% vs. 76.7%; P < 0.001). In the patients who had syncope in both DDD and DDD-CLS mode, DDD-CLS significantly delayed the onset of syncope during HUTT (from 20.8 ± 3.9 to 24.8 ± 0.9 min; P = 0.032). The maximum fall in systolic blood pressure recorded during HUTT was significantly lower in DDD-CLS compared with DDD (43.2 ± 30.3 vs. 65.1 ± 25.8 mmHg; P = 0.004). Conclusion: In patients with cardioinhibitory VVS, CLS reduces the occurrence of syncope induced by HUTT, compared with DDD pacing. When CLS is not able to abort the vasovagal reflex, it seems to delay the onset of syncope.

Reduced long-term overall mortality in heart failure patients with prolonged QRS treated with CRT combined with ICD vs. heart failure patients with narrow QRS treated with ICD only.

AIMS: It is not known whether heart failure (HF) patients with prolonged QRS who undergo cardiac resynchronization therapy combined with a defibrillator (CRT-D) have a prognostic advantage over HF patients with narrow QRS (therefore without indication for CRT) treated with an implantable cardioverter defibrillator (ICD) only. The aim of this study was to compare the long-term mortality of a group of HF patients with prolonged QRS receiving CRT-D with that of a similar group of patients with narrow QRS receiving ICD only. METHODS AND RESULTS: A total of 312 patients (mean age 66 ± 13 years; 84% male, mean left ventricular ejection fraction 25 ± 4%, mean New York Heart Association class 2.6 ± 0.5) were included in the analysis. Of these, 138 with a QRS complex duration ≥120 ms received a CRT-D. During follow-up, the time and cause of death were assessed. During a median follow-up of 46 months, CRT-D patients showed significantly lower overall mortality (P = 0.038). Compared with patients receiving ICD only, CRT-D patients showed lower HF mortality (P = 0.003). Coronary mortality, non-cardiac mortality, and sudden mortality were similar in both groups (all P > 0.05). A positive response to CRT was an independent predictor of reduced mortality on multivariate analysis (hazard ratio: 0.27; P = 0.047). CONCLUSION: In HF patients treated with ICD, the subgroup of patients with prolonged QRS who receive CRT-D displays better long-term survival than narrow QRS ICD recipients, owing to their reduced HF mortality.

Relationship between seasonal weather changes, risk of dehydration, and incidence of severe bradyarrhythmias requiring urgent temporary transvenous cardiac pacing in an elderly population.

There is little information on any seasonal variations or meteorological factors associated with symptomatic bradyarrhythmias requiring cardiac pacing. The aim of this single-center study was to investigate the seasonal distribution of the incidence of severe, life-threatening bradyarrhythmias requiring urgent temporary transvenous cardiac pacing in an elderly population. Consecutive patients who underwent urgent temporary transvenous cardiac pacing between 2007 and 2012 were enrolled. The baseline characteristics of the patients and some meteorological parameters, including the calculation the daily heat index (HI), were recorded. During the study period, 79 consecutive patients (mean age 82 ± 8 years, 41% male) underwent urgent temporary transvenous cardiac pacing, mainly for third-degree atrioventricular block (79%). The incidence of bradyarrhythmias was significantly higher in summer than in the other seasons (P < 0.001). Moreover, the highest incidence was observed in months with HI > 90 °F for >3 h per day for at least 10 days (P < 0.001). A direct correlation was found between the average monthly temperature and the monthly number of patients undergoing temporary cardiac pacing (r = 0.54, P < 0.001). Compared with other patients, those observed during the hottest months were significantly older and more frequently affected by chronic disabling neurological diseases (all P < 0.05). In addition, they more frequently showed biochemical indices of dehydration, renal function impairment and hyperkalemia (all P < 0.05). This study showed an increased incidence of severe bradyarrhythmias in an elderly population during the hottest months of the year. In these months, in subjects characterized by increased susceptibility to dehydration, the risk of developing bradyarrhythmias was increased significantly.

[Assessment of physical activity levels in a sample of the Italian adult population]. / Valutazione dell'attività fisica in un gruppo di popolazione adulta italiana.

A cross-sectional study was performed to evaluate, amongst a sample of the Italian adult population, physical activity levels and adherence to international recommendations. Overall, 220 subjects were recruited. Study participants completed a lifestyle questionnaire after seven consecutive days of monitoring by an accelerometer. The study population was found to devote most of their time to sedentary activities, but over half of the sample reached minimum levels of physical activity recommended by the World Health Organization.

Rate, causes, and impact on patient outcome of implantable device complications requiring surgical revision: large population survey from two centres in Italy.

AIMS: The long-term impact of implantable device-related complications on the patient outcome has not been thoroughly evaluated. The aims of this retrospective, bi-centre study were to analyse the rate and nature of device-related complications requiring surgical revision in a large series of patients undergoing device implantation, elective generator replacement and pacing system upgrade and to systematically assess the impact of such complications on patient outcome and healthcare utilization. METHODS AND RESULTS: Data from 2671 consecutive procedures (1511 device implantations, 1034 elective generator replacements, and 126 pacing system upgrades) performed between January 2006 and March 2011 were retrospectively analysed. The outcome measures recorded were complication-related mortality, number of re-operations, need for complex surgical procedures, number of re-hospitalizations, and additional hospital treatment days. Over a median follow-up of 27 months, the overall rate of complications was 2.8% per procedure-year [9.5% in cardiac resynchronisation therapy (CRT) device implantation, 6.1% in pacing system upgrade, 3.5% in implantable cardioverter defibrillator implantation, 1.7% in pacemaker implantation, and 1.7% in generator replacement). The procedure with the highest risk of complications was CRT device implantation (odds ratio: 6.6; P < 0.001); these complications primarily involved coronary sinus lead dislodgement and device infection. Patients with complications had a significantly higher number of device-related hospitalizations (2.3 ± 0.6 vs. 1.0 ± 0.1; P < 0.001) and hospital treatment days (15.7 ± 25.1 vs. 3.6 ± 1.1; P < 0.001) than those without complications. Device infection was the complication with the greatest negative impact on patient outcome. CONCLUSION: Cardiac resynchronisation therapy implantation was the procedure with the highest risk of complications requiring surgical revision. Complications were associated with substantial clinical consequences and a significant increase in the number and length of hospitalizations.

Closed-loop cardiac pacing vs. conventional dual-chamber pacing with specialized sensing and pacing algorithms for syncope prevention in patients with refractory vasovagal syncope: results of a long-term follow-up.

AIMS: Closed-loop stimulation (CLS) pacing has shown greater efficacy in preventing the recurrence of vasovagal syncope (VVS) in patients with a cardioinhibitory response to head-up tilt test (HUTT) compared with conventional pacing. Moreover, there is no conclusive evidence to support the superiority of CLS over the conventional algorithms for syncope prevention. This study retrospectively evaluated the effectiveness of CLS pacing compared with dual-chamber pacing with conventional specialized sensing and pacing algorithms for syncope prevention in the prevention of syncope recurrence in patients with refractory VVS and a cardioinhibitory response to HUTT during a long-term follow-up. METHODS AND RESULTS: Forty-one patients (44% male, 53 ± 16 years) with recurrent, refractory VVS (26% with trauma) and a cardioinhibitory response to HUTT who had undergone pacemaker implantation were included in the analysis. Twenty-five patients received a dual-chamber CLS pacemaker (CLS group) and 16 patients received a dual-chamber pacemaker with conventional algorithms for syncope prevention (conventional pacing group): 9 patients with Medtronic rate drop response algorithm and 7 patients with Guidant-Boston Scientific sudden brady response algorithm. During the follow-up (mean 4.4 ± 3.0 years, interquartile range 2.2-7.4 years) one patient (4%) in the CLS group and six (38%) in the conventional pacing group had syncope recurrences (P= 0.016). The Kaplan-Meier actuarial estimate of first recurrence of syncope after 8 years was 4% in the CLS group and 40% in the conventional pacing group (P= 0.010). CONCLUSIONS: The results of this retrospective analysis show that, in order to prevent a recurrence of VVS in patients with a cardioinhibitory response to HUTT, dual-chamber CLS pacing was more effective than dual-chamber pacing with conventional algorithms for syncope prevention in preventing bradycardia-related syncope.

Reliability and validity of a screen time-based sedentary behaviour questionnaire for adolescents: The HELENA study.

BACKGROUND: Although there is a growing interest in the epidemiology of sedentary behaviours, it is unknown whether sedentary behaviour questionnaires are broad markers of sedentary time. The aims of this study were to determine the: (i) reliability of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) screen time-based sedentary behaviour questionnaire; and (ii) its validity, i.e. the ability of the questionnaire to correctly rank adolescents according to the objectively measured sedentary time. METHODS: A total of 183 adolescents (104 females aged 12.5-17.5 years) were involved in the reliability study. Participants completed the HELENA sedentary questionnaire twice (1 week apart). The validity study comprised 2048 (1212 females) adolescents (12.5-17.5 years of age) included in the HELENA cross-sectional study. Questions included television viewing, computer games, console games, Internet for study and non-study reasons and study during week and weekend days. We compared median values of sedentary time, using accelerometers, by tertiles of self-reported sedentary behaviours and their sum (composite sedentary score). RESULTS: Reliability study: κ-values showed a good agreement (>0.7), except for Internet for study reasons (0.46 weekdays, 0.33 weekend). The questionnaire correctly classified boys' sedentary time when analysed by specific behaviours and by a composite sedentary score. In girls, median values of objectively measured sedentary time were not different across tertiles of self-reported sedentary behaviours or the composite sedentary score. CONCLUSION: The HELENA sedentary questionnaire is reliable, yet only correctly classifies objectively measured sedentary time in boys.

Active relatives and health-related physical fitness in European adolescents: the HELENA Study.

High physical fitness in childhood and adolescence is positively associated with favourable health-related outcomes. Our aim was to examine the relationship between relatives' (father, mother, brother, sister, and best friend) physical activity engagement and encouragement on adolescents' physical fitness. Adolescents were part of the HELENA study, a multi-centre study conducted in 10 cities from nine European countries in 2006-2008. Participants were 3288 adolescents (48% boys, 52% girls) aged 12.5-17.5 years with valid data on at least one of the three fitness variables studied: muscular strength (standing long jump), speed/agility (4×10 m shuttle run), and cardiorespiratory fitness (20 m shuttle run). The adolescents reported their relatives' physical activity engagement and encouragement. Analysis of covariance showed that relatives' physical activity engagement (father, mother, brother, and best friend) was positively related to cardiorespiratory fitness (P < 0.05); and mother's and sisters' physical activity engagement were positively associated with higher muscular strength in adolescents (P < 0.05). Furthermore, father's physical activity encouragement was positively linked to physical fitness (all fitness components) in adolescents (P < 0.05). Interventions aimed at improving physical fitness in young people might be more successful when family members, particularly mothers and fathers, are encouraged to engage in physical activity and support adolescents' physical activity.

Anemia does not preclude increments in cardiac performance during a short period of intensive, exercise-based cardiac rehabilitation.

BACKGROUND AND AIMS: Anemia seems to be rather common in cardiac rehabilitation patients but it is not known whether it could influence cardiovascular performance indexes and prognosis immediately after an acute cardiac event. The purposes of this study were to define its prevalence and to investigate the safety and efficacy of an intensive exercise-based cardiac rehabilitation in patients with and without anemia. METHODS: 436 participants (77% males; mean age 64 ± 13 years) were submitted to a two-week cardiac rehabilitation program consisting of low to medium intensity, individualized training with respiratory, aerobic and calisthenic exercises (three sessions daily, six times per week). A six-minute walking test was performed at enrolment and repeated at discharge together with a cardiopulmonary test. RESULTS: Anemia, as defined according to World Health Organization criteria, was detected in 328 patients (75.2% of the entire population). The distance walked increased from 381 ± 117 m at baseline to 457 ± 110 m (p < 0.001) after a mean period of 12.4 ± 4 days. A direct correlation was found between hemoglobin concentrations and both the absolute distance walked (r = 0.48; p < 0.001) and peak VO(2) (r = 0.39; p < 0.001). Anemic patients walked a significantly shorter distance at baseline and at discharge (p < 0.001); however, both groups showed the same increment in the distance walked: 76.0 ± 61 m vs 76.0 ± 60 m (p = 0.99). CONCLUSIONS: Our data indicate: 1) a high prevalence of anemia in the study population and 2) that, in spite of a clear reduction in exercise capacity, a moderate anemia does not preclude increments in cardiac performance during a short period of intensive, exercise-based cardiac rehabilitation.

Mediterranean Diet Effect: an Italian picture.

BACKGROUND: The purpose of this study was to evaluate the overall diet quality effects, mainly on antioxidant nutritional status and some cytokines related to the cellular immune response as well as oxidative stress in a healthy Italian population group. METHODS: An observational study was conducted on 131 healthy free-living subjects. Dietary intake was assessed by dietary diary. Standardised procedures were used to make anthropometric measurements. On blood samples (serum, plasma and whole blood) were evaluated: antioxidant status by vitamin A, vitamin E, carotenoids, vitamin C, uric acid, SH groups, SOD and GPx activities; lipid blood profile by total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides; total antioxidant capacity by FRAP and TRAP; the immune status by TNF-α, and IL-10 cytokines; the levels of malondialdehyde in the erythrocytes as marker of lipid peroxidation. RESULTS: The daily macronutrients intake (g/day) have shown a high lipids consumption and significant differences between the sexes with regard to daily micronutrients intake. On total sample mean Mediterranean Diet Score (MDS) was 4.5 ± 1.6 and no significant differences between the sexes were present. A greater adherence to a Mediterranean dietary pattern increases the circulating plasma levels of carotenoids (lutein plus zeaxanthin, cryptoxanthin, α and ß-carotene), vitamin A and vitamin E. The levels of endogenous antioxidants were also improved. We observed higher levels in anti-inflammatory effect cytokines (IL-10) in subjects with MDS ≥ 6, by contrast, subjects with MDS ≤ 3 show higher levels in sense of proinflammatory (TNF α P < 0.05). Lower levels of MDA were associated with MDS > 4. Our data suggest a protective role of vitamin A against chronic inflammatory conditions especially in subjects with the highest adherence to the Mediterranean-type dietary pattern. CONCLUSIONS: Mediterranean dietary pattern is associated with significant amelioration of multiple risk factors, including a better cardiovascular risk profile, reduced oxidative stress and modulation of inflammation.

Clustering patterns of physical activity, sedentary and dietary behavior among European adolescents: The HELENA study.

BACKGROUND: Evidence suggests possible synergetic effects of multiple lifestyle behaviors on health risks like obesity and other health outcomes. A better insight in the clustering of those behaviors, could help to identify groups who are at risk in developing chronic diseases. This study examines the prevalence and clustering of physical activity, sedentary and dietary patterns among European adolescents and investigates if the identified clusters could be characterized by socio-demographic factors. METHODS: The study comprised a total of 2084 adolescents (45.6% male), from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Physical activity and sedentary behavior were measured using self-reported questionnaires and diet quality was assessed based on dietary recall. Based on the results of those three indices, cluster analyses were performed. To identify gender differences and associations with socio-demographic variables, chi-square tests were executed. RESULTS: Five stable and meaningful clusters were found. Only 18% of the adolescents showed healthy and 21% unhealthy scores on all three included indices. Males were highly presented in the cluster with high levels of moderate to vigorous physical activity (MVPA) and low quality diets. The clusters with low levels of MVPA and high quality diets comprised more female adolescents. Adolescents with low educated parents had diets of lower quality and spent more time in sedentary activities. In addition, the clusters with high levels of MVPA comprised more adolescents of the younger age category. CONCLUSION: In order to develop effective primary prevention strategies, it would be important to consider multiple health indices when identifying high risk groups.

Leadless pacemaker versus transvenous single-chamber pacemaker therapy: peri-procedural aspects, utilization of medical resources and patient acceptance.

BACKGROUND: Leadless pacemaker (L-PM) have been developed in order to overcome the lead- and pocket-related complications associated with transvenous pacemaker (T-PM). The impact of L-PM implantation on the utilization of medical resources, patient comfort and therapy acceptance could differ from that of T-PM. RESEARCH DESIGN AND METHODS: Prospective, single-center study enrolling 243 consecutive patients undergoing PM implantation. Propensity matching for baseline characteristics yielded 77 matched pairs. Procedural data, patient acceptance (assessed by Florida Patient Acceptance Survey, FPAS) and quality of life (QoL) (assessed at the baseline, 1 week, 3 and 6 months) were compared between the two groups (L-PM and T-PM). RESULTS: The implantation procedure was longer in L-PM than T-PM patients (42.2±16.3 vs. 28.9±11.9 minutes; p<0.001). L-PM was associated with lower intra- and post-operative pain intensity (all p<0.05), shorter hospitalization (3.2±0.5 vs. 3.5±1.1 days; p=0.034), greater patient acceptance (FPAS score: 58.7±7.1 vs. 40.5±4.1; p<0.001), and better QoL on both physical and mental health scales (all p<0.05). CONCLUSIONS: Although L-PM implantation takes longer than T-PM, it is better tolerated and accepted by patients and is associated with a better QoL.

Effectiveness of Implantable DEfibrillators Alert Systems: comparison between audible and vibratory alert: IDEAS study.

INTRODUCTION: Implantable cardioverter-defibrillator (ICD) alarm systems are an important means of monitoring device functioning. The aim of this study was to compare the ability of patients with sense two types of device alert systems: an audible alert and a vibratory alarm. METHODS: The ability to recognize the alarms was assessed in three alarm tests performed in a series of consecutive ICD patients enrolled during routine outpatient device follow-up. To avoid overestimating the rate of patients able to sense the alarm, the first test was performed without forewarning. Subsequently, the second test was performed after the patients had been forewarned. Finally, to assess the learning effect of a demonstration test, a third test was performed, again without forewarning. RESULTS: A total of 528 patients (65.4 ±â€Š14.4 years, 74.6% male) were enrolled: 347 (65.7%) with an audible alert-endowed device and 181 (34.3%) with a vibratory alarm-endowed device. When emitted without warning, the alarms were sensed by 72.4% of patients. When patients were forewarned, the probability of sensing the alarms rose to 92.5% (P < 0.001). In both cases, the vibratory alarm was more likely to be sensed than the audible alert (77.3 vs. 67.7% in the first case; 96.1 vs. 87.9% in the second case; all P < 0.05). CONCLUSION: ICD alarms emitted in an outpatient setting are sensed by a large proportion of patients, but not by all. Training patients by means of demonstration tests significantly increases the rate of patients who recognize the alarm. Vibratory alarm seems to be more effective than audible alert.

Physical Activity Measured by Implanted Devices Predicts Atrial Arrhythmias and Patient Outcome: Results of IMPLANTED (Italian Multicentre Observational Registry on Patients With Implantable Devices Remotely Monitored).

BACKGROUND: To determine whether daily physical activity (PA), as measured by implanted devices (through accelerometer sensor), was related to the risk of developing atrial arrhythmias during long-term follow-up in a population of heart failure (HF) patients with an implantable cardioverter defibrillator (ICD). METHODS AND RESULTS: The study population was divided into 2 equally sized groups (PA cutoff point: 3.5 h/d) according to their mean daily PA recorded by the device during the 30- to 60-day period post-ICD implantation. Propensity score matching was used to compare 2 equally sized cohorts with similar characteristics between lower and higher activity patients. The primary end point was time free from the first atrial high-rate episode (AHRE) of duration ≥6 minutes. Secondary end points were: first AHRE ≥6 hours, first AHRE ≥48 hours, and a combined end point of death or HF hospitalization. Data from 770 patients (65±15 years; 66% men; left ventricular ejection fraction 35±12%) remotely monitored for a median of 25 months were analyzed. A PA ≥3.5 h/d was associated with a 38% relative reduction in the risk of AHRE ≥6 minutes (72-month cumulative survival: 75.0% versus 68.1%; log rank P=0.025), and with a reduction in the risk of AHRE ≥6 hours, AHRE ≥48 hours, and the combined end point of death or HF hospitalization (all P<0.05). CONCLUSIONS: In HF patients with ICD, a low level of daily PA was associated with a higher risk of atrial arrhythmias, regardless of the patients' baseline characteristics. In addition, a lower daily PA predicted death or HF hospitalization.

Lignan Content in Cereals, Buckwheat and Derived Foods.

Cereal foods are a fundamental part of a balanced diet and several studies have assigned to wholemeal cereal products a protective role in human health, due to their content of bioactive compounds. Within the phytochemicals, lignans are of increasing interest for their potential anticarcinogenic, antioxidant, estrogenic and antiestrogenic activities. The aim of this work is to contribute to the updating of food lignan databases by providing the profile and the amount of lignans in cereals, buckwheat and several cereal based foods commonly consumed in human diets. Values were taken from published papers. Items were divided in different groups, namely grains, brans andflours, bread, cereal staple foods, breakfast cereals and other cereal products, and values for secoisolariciresinol, matairesinol, pinoresinol, lariciresinol are given. For example, the total average values for the mentioned lignans in grains ranged between 23 µg/100 g and 401 µg/100 g dry weight. The contribution of each single lignan molecule to the total value of lignans appears to be different for every cereal species. Lignan content and typology in processed foods depends on the raw materials used, their degree of refinement and on processing conditions.

Predictive factors for pacemaker implantation in patients receiving an implantable loop recorder for syncope remained unexplained after an extensive cardiac and neurological workup.

BACKGROUND: Several previous implantable loop recorder (ILR) studies have shown bradyarrhythmic events requiring a pacemaker implantation in a significant proportion of patients with unexplained syncope (US). The aim of this observational, two-centre, study was to identify the predictive factors for pacemaker implantation in a population of patients receiving an ILR for US with suspected arrhythmic aetiology. METHODS: Fifty-six patients (mean age 68 years, 61% male) with a history of US and negative cardiac and neurological workup, who underwent ILR implantation, were enrolled. After the implantation, a follow-up visit was undertaken after symptomatic events or every 3 months in asymptomatic subjects. The end-point of the study was the detection of a bradyarrhythmia (with or without a syncopal recurrence) requiring pacemaker implantation. RESULTS: After a median ILR observation of 22 months, a clinically significant bradyarrhythmia was detected in 11 patients (20%), of which 9 cases related to syncopal relapses. In the multivariable analysis, three independent predictive factors for pacemaker implantation were identified: an age >75 years (odd ratio [OR]: 29.9; p=0.035); a history of trauma secondary to syncope (OR: 26.8; p=0.039); and the detection of periods of asymptomatic bradycardia, not sufficient to explain the mechanism of syncope, during conventional ECG monitoring (through 24 h Holter or in hospital telemetry), performed before ILR implantation (OR: 24.7; p=0.045). CONCLUSIONS: An advanced age, a history of trauma secondary to syncope, and the detection of periods of asymptomatic bradycardia during conventional ECG monitoring were independent predictive factors for bradyarrhythmias requiring pacemaker implantation in patients receiving an ILR for US.

Common polymorphisms in six genes of the methyl group metabolism pathway and obesity in European adolescents.

OBJECTIVE: The goal of the present study was to assess the relationship between the genetic variability in six genes of methyl group (CH(3)) metabolism and the risk of obesity. METHODS: Single nucleotide polymorphisms (SNP) were selected among the methylene-tetrahydrofolate reductase (MTHFR), methionine synthase (MTR), methionine synthase reductase (MTRR), cystationine betha-syntase (CBS), transcobalamin-II (TCN2) and paraoxonase-1 (PON1) genes. The associations between SNPs and the risk of obesity were assessed in a case-control study of obese and normal-weight adolescents (age: 14.9±1.2 years), and the relationship between SNPs and body fat markers (i.e., body mass index [BMI], percentage body fat [BF%] and waist circumference [WC]) in a cross-sectional study of 1 155 European adolescents (age: 14.8±1.4 years). Genotyping was performed on an Illumina system and plasma folate level was determined by immunoassay. RESULTS: In the case-control study, there was no evidence for any association between SNPs of MTHFR, MTR, CBS, TCN2 and PON1 and obesity (all p values ≥0.08). In contrast, two SNPs of MTRR were associated with a higher (rs10520873, Odds Ratio: 1.68 [1.18-2.39]; p=0.004) or lower (rs1801394, 0.61 [0.42-0.87]; p=0.007) risk of obesity. In the cross-sectional sample, rs1801394 was associated with lower BMI (p=0.03) and lower waist circumference (p=0.02). However, after Bonferroni correction these associations were no longer significant. No other significant association or interaction between folate levels and SNPs were detected for anthropometric variables. CONCLUSION: Our findings do not support an association between MTHFR, MTR, CBS, TCN2 and PON1 SNPs and obesity in adolescence. Further investigations are necessary to confirm the possible association between the rs1801394 variant of MTRR and obesity.

Fitness and fatness are independently associated with markers of insulin resistance in European adolescents; the HELENA study.

OBJECTIVE: To examine the independent association of total and central body fat and cardiorespiratory fitness with markers of insulin resistance after controlling for several potential confounders in European adolescents participating in the HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional) study. METHODS: We conducted a cross sectional study (the HELENA-CSS) which comprised 1053 (12.5-17.5 years) adolescents from 10 European cities. Weight, height, waist circumference and skinfold thickness were measured, and body mass index (BMI) was calculated. Cardiorespiratory fitness was measured by the 20-m shuttle run test. Markers of insulin resistance were fasting insulin and glucose, and homeostasis model assessment (HOMA). RESULTS: HOMA and insulin were positively associated with BMI, skinfolds and waist circumference after controlling for center, age, pubertal status and cardiorespiratory fitness (all P ? 0.01). HOMA and insulin were negatively associated with cardiorespiratory fitness in adolescents with moderate to high levels of total and central body fat (all P ? 0.01). CONCLUSIONS: HOMA and insulin were associated with total and central body fat in European adolescents. Moreover, cardiorespiratory fitness explained a part of the HOMA and insulin variance in those adolescents with moderate to high levels of total and central body fat, and also, to some extent, in those with low to middle fat mass.