A Morphometric Approach to Understand Prokaryoplankton: A Study in the Sicily Channel (Central Mediterranean Sea).

A new understanding of plankton ecology has been obtained by studying the phenotypic traits of free-living prokaryotes in the Sicily Channel (Central Mediterranean Sea), an area characterised by oligotrophic conditions. During three cruises carried out in July 2012, January 2013 and July 2013, the volume and morphology of prokaryotic cells were assessed microscopically using image analysis in relation to environmental conditions. The study found significant differences in cell morphologies among cruises. The largest cell volumes were observed in the July 2012 cruise (0.170 ± 0.156 µm3), and the smallest in the January 2013 cruise (0.060 ± 0.052 µm3). Cell volume was negatively limited by nutrients and positively by salinity. Seven cellular morphotypes were observed among which cocci, rods and coccobacilli were the most abundant. Cocci, although they prevailed numerically, always showed the smallest volumes. Elongated shapes were positively related to temperature. Relationships between cell morphologies and environmental drivers indicated a bottom-up control of the prokaryotic community. The morphology/morphometry-based approach is a useful tool for studying the prokaryotic community in microbial ecology and should be widely applied to marine microbial populations in nature.

Cerebral Microbleeds During Transcatheter Aortic Valve Replacement: A Prospective Magnetic Resonance Imaging Cohort.

BACKGROUND: Cerebral microbleeds (CMBs) have been observed in healthy elderly people undergoing systematic brain magnetic resonance imaging. The potential role of acute triggers on the appearance of CMBs remains unknown. We aimed to describe the incidence of new CMBs after transcatheter aortic valve replacement (TAVR) and to identify clinical and procedural factors associated with new CMBs including hemostatic measures and anticoagulation management. METHODS: We evaluated a prospective cohort of patients with symptomatic aortic stenosis referred for TAVR for CMBs (METHYSTROKE [Identification of Epigenetic Risk Factors for Ischemic Complication During the TAVR Procedure in the Elderly]). Standardized neurologic assessment, brain magnetic resonance imaging, and analysis of hemostatic measures including von Willebrand factor were performed before and after TAVR. Numbers and location of microbleeds on preprocedural magnetic resonance imaging and of new microbleeds on postprocedural magnetic resonance imaging were reported by 2 independent neuroradiologists blinded to clinical data. Measures associated with new microbleeds and postprocedural outcome including neurologic functional outcome at 6 months were also examined. RESULTS: A total of 84 patients (47% men, 80.9±5.7 years of age) were included. On preprocedural magnetic resonance imaging, 22 patients (26% [95% CI, 17%-37%]) had at least 1 microbleed. After TAVR, new microbleeds were observed in 19 (23% [95% CI, 14%-33%]) patients. The occurrence of new microbleeds was independent of the presence of microbleeds at baseline and of diffusion-weighted imaging hypersignals. In univariable analysis, a previous history of bleeding (P=0.01), a higher total dose of heparin (P=0.02), a prolonged procedure (P=0.03), absence of protamine reversion (P=0.04), higher final activated partial thromboplastin time (P=0.05), lower final von Willebrand factor high-molecular-weight:multimer ratio (P=0.007), and lower final closure time with adenosine-diphosphate (P=0.02) were associated with the occurrence of new postprocedural microbleeds. In multivariable analysis, a prolonged procedure (odds ratio, 1.22 [95% CI, 1.03-1.73] for every 5 minutes of fluoroscopy time; P=0.02) and postprocedural acquired von Willebrand factor defect (odds ratio, 1.42 [95% CI, 1.08-1.89] for every lower 0.1 unit of high-molecular-weight:multimer ratio; P=0.004) were independently associated with the occurrence of new postprocedural microbleeds. New CMBs were not associated with changes in neurologic functional outcome or quality of life at 6 months. CONCLUSIONS: One out of 4 patients undergoing TAVR has CMBs before the procedure and 1 out of 4 patients develops new CMBs. Procedural or antithrombotic management and persistence of acquired von Willebrand factor defect were associated with the occurrence of new CMBs. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02972008.

Balloon aortic valvuloplasty for severe aortic stenosis before urgent non-cardiac surgery.

BACKGROUND: Balloon aortic valvuloplasty (BAV) has been proposed as a therapeutic option in patients suffering from severe aortic stenosis (SAS) who need urgent non-cardiac surgery (NCS). Whether this strategy is better than medical therapy in this very specific population is unknown. AIMS: We aimed to evaluate the clinical benefit of an invasive strategy (IS) with preoperative BAV in patients with SAS requiring urgent NCS. METHODS: From 2011 to 2019, a registry conducted in two centres included 133 patients with SAS undergoing urgent NCS, of whom 93 underwent preoperative BAV (IS) and 40 a conservative strategy (CS) without BAV. All analyses were adjusted for confounding using inverse probability of treatment weighting (IPTW) (10 clinical and anatomical variables). RESULTS: The primary outcome was MACE at one-month follow-up after NCS including mortality, heart failure, and other cardiovascular outcomes. In patients managed conservatively, occurrence of MACE was 20.0% (n=8) and death was 10.0% (n=4) at 1 month. In patients undergoing BAV, the occurrence of MACE was 20.4% (n=19) and death was 5.4% (n=5) at 1 month. Among patients undergoing conservative management, all events were observed after NCS while, in patients undergoing BAV, 12.9% (n=12) had events between BAV and NCS including 3 deaths, and 7.5% (n=7) had events after NCS including 2 deaths. In IPTW propensity analyses, the incidence of the primary outcome (20.4% vs 20.0%; OR 0.93, 95% CI: 0.38-2.29) and three-month survival (89.2% vs 90.0%; IPTW-adjusted HR 0.90, 95% CI: 0.31-2.60) were similar in both groups. CONCLUSIONS: Patients with SAS managed conservatively before urgent NCS are at high risk of events. A systematic invasive strategy using BAV does not provide a significant improvement in clinical outcome.

Myocardial Infarction incidence during national lockdown in two French provinces unevenly affected by COVID-19 outbreak: An observational study.

BACKGROUND: A reduction of admission for MI has been reported in most countries affected by COVID-19. No clear explanation has been provided. METHODS: To report the incidence of myocardial infarction (MI) admission during COVID-19 pandemic and in particular during national lockdown in two unequally affected French provinces (10-million inhabitants) with a different media strategy, and to describe the magnitude of MI incidence changes relative to the incidence of COVID-19-related deaths. A longitudinal study to collect all MIs from January 1 until May 17, 2020 (study period) and from the identical time period in 2019 (control period) was conducted in all centers with PCI-facilities in northern "Hauts-de-France" province and western "Pays-de-la-Loire" Province. The incidence of COVID-19 fatalities was also collected. FINDINGS: In "Hauts-de-France", during lockdown (March 18-May 10), 1500 COVID-19-related deaths were observed. A 23% decrease in MI-IR (IRR=0.77;95%CI:0.71-0.84, p<0.001) was observed for a loss of 272 MIs (95%CI:-363,-181), representing 18% of COVID-19-related deaths. In "Pays-de-la-Loire", 382 COVID-19-related deaths were observed. A 19% decrease in MI-IR (IRR=0.81; 95%CI=0.73-0.90, p<0.001) was observed for a loss of 138 MIs (95%CI:-210,-66), representing 36% of COVID-19-related deaths. While in "Hauts-de-France" the MI decline started before lockdown and recovered 3 weeks before its end, in "Pays-de-la-Loire", it started after lockdown and recovered only by its end. In-hospital mortality of MI patients was increased during lockdown in both provinces (5.0% vs 3.4%, p=0.02). INTERPRETATION: It highlights one of the potential collateral damages of COVID-19 outbreak on cardiovascular health with a dramatic reduction of MI incidence. It advocates for a careful and weighted communication strategy in pandemic crises. FUNDING: The study was conducted without external funding.

Feasibility and safety of transfemoral transcatheter aortic valve implantation performed with a percutaneous coronary intervention-like approach.

BACKGROUND: Transfemoral percutaneous transcatheter aortic valve implantation (TF-TAVI) is a safe, reproducible and established procedure, mainly performed under local anaesthesia, which is mostly administered and monitored by a dedicated anaesthesia team (regular approach). Our centre has developed a standardized pathway of care, and eligible patients are selected for a minimalist TF-TAVI, entirely managed by operators without the presence of the anaesthesia team in the operating room, like most interventional coronary procedures ("percutaneous coronary intervention-like" approach [PCI approach]). AIM: To compare the safety and efficacy of TF-TAVI performed with the PCI approach versus the regular approach. METHODS: The analysis population comprised all patients who underwent TF-TAVI with the PCI or regular approach in our institution from November 2016 to July 2019. The two co-primary endpoints were early safety composite and early efficacy composite at 30days as defined by the Valve Academic Research Consortium-2. The PCI (n=137) and Regular (n=221) approaches were compared using the propensity score based method of inverse probability of treatment weighting. RESULTS: No differences were observed after comparison of TAVI performed with the PCI or regular approach regarding the composite safety endpoint (7.3% vs. 11.3%; odds ratio 0.63, 95% confidence interval 0.37 to 1.07; P=0.086) or the composite efficacy endpoint (4.4% vs. 6.3%; odds ratio 0.78, 95% confidence interval 0.41 to 1.49; P=0.45). CONCLUSIONS: This study suggests that the efficacy and safety of TF-TAVI entirely managed by a PCI approach for selected patients are not different to those when TF-TAVI is performed with the attendance of a full anaesthesia care team. The PCI approach appears to be a safe and efficient clinical pathway, providing an appropriate and rational utilization of anaesthesiology resources, and could be used for the majority of TF-TAVI procedures.

IMPELLA® or Extracorporeal Membrane Oxygenation for Left Ventricular Dominant Refractory Cardiogenic Shock.

Mechanical circulatory support (MCS) devices are effective tools in managing refractory cardiogenic shock (CS). Data comparing veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and IMPELLA® are however scarce. We aimed to assess outcomes of patients implanted with these two devices and eligible to both systems. From 2004 to 2020, we retrospectively analyzed 128 patients who underwent VA-ECMO or IMPELLA® in our institution for refractory left ventricle (LV) dominant CS. All patients were eligible to both systems: 97 patients were first implanted with VA-ECMO and 31 with IMPELLA®. The primary endpoint was 30-day all-cause death. VA-ECMO patients were younger (52 vs. 59.4, p = 0.006) and had a higher lactate level at baseline than those in the IMPELLA® group (6.84 vs. 3.03 mmol/L, p < 0.001). Duration of MCS was similar between groups (9.4 days vs. 6 days in the VA-ECMO and IMPELLA® groups respectively, p = 0.077). In unadjusted analysis, no significant difference was observed between groups in 30-day mortality: 43.3% vs. 58.1% in the VA-ECMO and IMPELLA® groups, respectively (p = 0.152). After adjustment, VA-ECMO was associated with a significant reduction in 30-day mortality (HR = 0.25, p = 0.004). A higher rate of MCS escalation was observed in the IMPELLA® group: 32.3% vs. 10.3% (p = 0.003). In patients eligible to either VA-ECMO or IMPELLA® for LV dominant refractory CS, VA-ECMO was associated with improved survival rate and a lower need for escalation.

A review on the geochemistry of lakes in Victoria Land (Antarctica).

This paper reports briefly the concentrations of major elements of 3116 samples of lakes in the Victoria Land region. The data obtained by different works were processed through multivariate chemometric techniques to gain insight into the biogeochemical processes taking place in the lacustrine systems. Antarctic ice-free areas contain lakes and ponds that have interesting chemical features and are of wide global significance as early warning indicators of climatic and environmental change.

Ultrasound Guidance to Reduce Vascular and Bleeding Complications of Percutaneous Transfemoral Transcatheter Aortic Valve Replacement: A Propensity Score-Matched Comparison.

Background Ultrasound (US) guidance provides the unique opportunity to control the puncture zone of the artery during transfemoral transcatheter aortic valve replacement and may decrease major vascular complications (VC) and life-threatening or major bleeding complications. This study aimed to evaluate the clinical impact of US guidance using a propensity score-matched comparison. Methods and Results US guidance was implemented as the default approach for all transfemoral transcatheter aortic valve replacement cases in our institution in June 2013. We defined 3 groups of consecutive patients according to the method of puncture (fluoroscopic/US guidance) and the use of a transcatheter heart valve. Patients in the US-guided second-generation group (Sapien XT [Edwards Lifesciences, Irvine, CA], Corevalve [Medtronic, Dublin, Ireland]) were successfully 1:1 matched with patients in the fluoroscope-guided second-generation group (n=95) with propensity score matching. In a second analysis we described the consecutive patients of the US-guided third-generation group (Evolut-R [Medtronic], Sapien 3 [Edwards Lifesciences], n=308). All vascular and bleeding complications were reduced in the US-guided second-generation group compared with the fluoroscope-guided second-generation group: VC (16.8% versus 6.3%; P=0.023); life-threatening or major bleeding (22.1% versus 6%; P=0.004); and VC related to vascular access (12.6% versus 4.2%; P=0.052). In the US-guided third-generation group the rates of major VC and life-threatening or major bleeding were 3.2% (95% CI, 1.6% to 5.9%) and 3.6% (95% CI, 1.8% to 6.3%). In the overall population (n=546), life-threatening or major bleeding was associated with a 1.7-fold increased mortality risk (P=0.02). Conclusions We demonstrated that US guidance effectively reduced VC and bleeding complications for transfemoral transcatheter aortic valve replacement and should be considered the standard puncture method. Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT02628509.

Usefulness of Routine Fractional Flow Reserve for Clinical Management of Coronary Artery Disease in Patients With Diabetes.

Importance: Approximately one-third of patients considered for coronary revascularization have diabetes, which is a major determinant of clinical outcomes, often influencing the choice of the revascularization strategy. The usefulness of fractional flow reserve (FFR) to guide treatment in this population is understudied and has been questioned. Objective: To evaluate the usefulness and rate of major adverse cardiovascular events (MACE) of integrating FFR in management decisions for patients with diabetes who undergo coronary angiography. Design, Setting, and Participants: This cross-sectional study used data from the PRIME-FFR study derived from the merger of the POST-IT study (Portuguese Study on the Evaluation of FFR-Guided Treatment of Coronary Disease [March 2012-November 2013]) and R3F study (French Study of FFR Integrated Multicenter Registries Implementation of FFR in Routine Practice [October 2008-June 2010]), 2 prospective multicenter registries that shared a common design. A population of all-comers for whom angiography disclosed ambiguous lesions was analyzed for rates, patterns, and outcomes associated with management reclassification, including revascularization deferral, in patients with vs without diabetes. Data analysis was performed from June to August 2018. Main Outcomes and Measures: Death from any cause, myocardial infarction, or unplanned revascularization (MACE) at 1 year. Results: Among 1983 patients (1503 [77%] male; mean [SD] age, 65 [10] years), 701 had diabetes, and FFR was performed for 1.4 lesions per patient (58.2% of lesions in the left anterior descending artery; mean [SD] stenosis, 56% [11%]; mean [SD] FFR, 0.81 [0.01]). Reclassification by FFR was high and similar in patients with and without diabetes (41.2% vs 37.5%, P = .13), but reclassification from medical treatment to revascularization was more frequent in the former (142 of 342 [41.5%] vs 230 of 730 [31.5%], P = .001). There was no statistical difference between the 1-year rates of MACE in reclassified (9.7%) and nonreclassified patients (12.0%) (P = .37). Among patients with diabetes, FFR-based deferral identified patients with a lower risk of MACE at 12 months (25 of 296 [8.4%]) compared with those undergoing revascularization (47 of 257 [13.1%]) (P = .04), and the rate was of the same magnitude of the observed rate among deferred patients without diabetes (7.9%, P = .87). Status of insulin treatment had no association with outcomes. Patients (6.6% of the population) in whom FFR was disregarded had the highest MACE rates regardless of diabetes status. Conclusions and Relevance: Routine integration of FFR for the management of coronary artery disease in patients with diabetes may be associated with a high rate of treatment reclassification. Management strategies guided by FFR, including revascularization deferral, may be useful for patients with diabetes.

Balloon-Expandable Versus Self-Expanding Transcatheter Aortic Valve Replacement: A Propensity-Matched Comparison From the FRANCE-TAVI Registry.

BACKGROUND: No randomized study powered to compare balloon expandable (BE) with self expanding (SE) transcatheter heart valves (THVs) on individual end points after transcatheter aortic valve replacement has been conducted to date. METHODS: From January 2013 to December 2015, the FRANCE-TAVI nationwide registry (Registry of Aortic Valve Bioprostheses Established by Catheter) included 12 141 patients undergoing BE-THV (Edwards, n=8038) or SE-THV (Medtronic, n=4103) for treatment of native aortic stenosis. Long term mortality status was available in all patients (median 20 months; interquartile range, 14 to 30). Patients treated with BE-THV (n=3910) were successfully matched 1:1 with 3910 patients treated with SE-THV by using propensity score (25 clinical, anatomical, and procedural variables) and by date of the procedure (within 3 months). The first coprimary outcome was ≥ moderate occurrence of paravalvular regurgitation or in-hospital mortality, or both. The second coprimary outcome was 2-year all-cause mortality. RESULTS: In propensity-matched analyses, the incidence of the first coprimary outcome was higher with SE-THV (19.8%) compared with BE-THV (11.9%; relative risk, 1.68 [95% CI, 1.46-1.91]; P<0.0001). Each component of the outcome was also higher in patients receiving SE-THV: ≥ moderate paravalvular regurgitation (15.5% versus 8.3%; relative risk, 1.90 [95% CI, 1.63-2.22]; P<0.0001) and in hospital mortality (5.6% versus 4.2%; relative risk, 1.34 [95% CI, 1.07-1.66]; P=0.01). During follow up, all cause mortality occurred in 899 patients treated with SE-THV (2-year mortality, 29.8%) and in 801 patients treated with BE-THV (2-year mortality, 26.6%; hazard ratio, 1.17 [95% CI, 1.06-1.29]; P=0.003). Similar results were found using inverse probability of treatment weighting using propensity score analysis. CONCLUSION: The present study suggests that use of SE-THV was associated with a higher risk of paravalvular regurgitation and higher in-hospital and 2-year mortality compared with use of BE-THV. These data strongly support the need for a randomized trial sufficiently powered to compare the latest generation of SE-THV and BE-THV. CLINICAL TRIAL REGISTRATION: https://www.clinicaltrials.gov. Unique identifier: NCT01777828.

Gonadal macrophage aggregates in fish: A preliminary quantitative study in red mullet.

A histological study was conducted in red mullet, Mullus barbatus, collected from two sites characterized by different anthropogenic impacts. The aim of the study was to assess sex-, size-, season- and site-related variation in gonadal macrophage aggregate (MA) size, number, and relative area. Gonadal MAs were most abundant in males than in females. The number of MA was significantly higher in males from the most impacted site in October, with larger individuals showing more MA than smaller ones. MAs were always found in ripe testes, whereas they occurred only in regressing ovaries. These preliminary findings suggest that the presence of ovarian MA in red mullet is most likely related to ovary regression after spawning, whereas the presence of testicular MA is not necessarily associated to gonad regression, and may vary with season, size, and water quality.

Long-run operation of a reverse electrodialysis system fed with wastewaters.

The performance of a Reverse ElectroDialysis (RED) system fed by unconventional wastewater solutions for long operational periods is analysed for the first time. The experimental campaign was divided in a series of five independent long-runs which combined real wastewater solutions with artificial solutions for at least 10 days. The time evolution of electrical variables, gross power output and net power output, considering also pumping losses, was monitored: power density values obtained during the long-runs are comparable to those found in literature with artificial feed solutions of similar salinity. The increase in pressure drops and the development of membrane fouling were the main detrimental factors of system performance. Pressure drops increase was related to the physical obstruction of the feed channels defined by the spacers, while membrane fouling was related to the adsorption of foulants over the membrane surfaces. In order to manage channels partial clogging and fouling, different kinds of easily implemented in situ backwashings (i.e. neutral, acid, alkaline) were adopted, without the need for an abrupt interruption of the RED unit operation. The application of periodic ElectroDialysis (ED) pulses is also tested as fouling prevention strategy. The results collected suggest that RED can be used to produce electric power by unworthy wastewaters, but additional studies are still needed to characterize better membrane fouling and further improve system performance with these solutions.

Prokaryotic Abundance and Activity in Permafrost of the Northern Victoria Land and Upper Victoria Valley (Antarctica).

Victoria Land permafrost harbours a potentially large pool of cold-affected microorganisms whose metabolic potential still remains underestimated. Three cores (BC-1, BC-2 and BC-3) drilled at different depths in Boulder Clay (Northern Victoria Land) and one sample (DY) collected from a core in the Dry Valleys (Upper Victoria Valley) were analysed to assess the prokaryotic abundance, viability, physiological profiles and potential metabolic rates. The cores drilled at Boulder Clay were a template of different ecological conditions (different temperature regime, ice content, exchanges with atmosphere and with liquid water) in the same small basin while the Dry Valleys site was very similar to BC-2 conditions but with a complete different geological history and ground ice type. Image analysis was adopted to determine cell abundance, size and shape as well as to quantify the potential viable and respiring cells by live/dead and 5-cyano-2,3-ditolyl-tetrazolium chloride staining, respectively. Subpopulation recognition by apparent nucleic acid contents was obtained by flow cytometry. Moreover, the physiological profiles at community level by Biolog-Ecoplate™ as well as the ectoenzymatic potential rates on proteinaceous (leucine-aminopeptidase) and glucidic (ß-glucosidase) organic matter and on organic phosphates (alkaline-phosphatase) by fluorogenic substrates were tested. The adopted methodological approach gave useful information regarding viability and metabolic performances of microbial community in permafrost. The occurrence of a multifaceted prokaryotic community in the Victoria Land permafrost and a large number of potentially viable and respiring cells (in the order of 104-105) were recognised. Subpopulations with a different apparent DNA content within the different samples were observed. The physiological profiles stressed various potential metabolic pathways among the samples and intense utilisation rates of polymeric carbon compounds and carbohydrates, mainly in deep samples. The measured enzymatic activity rates suggested the potential capability of the microbial community to decompose proteins and polysaccharides. The microbial community seems to be appropriate to contribute to biogeochemical cycling in this extreme environment.

A novel electrocardiographic predictor of clinical response to cardiac resynchronization therapy.

AIMS: A wide QRS with left bundle branch block pattern is usually required for cardiac resynchronization therapy (CRT) in patients with dilated cardiomyopathy. However, ∼30% of patients do not benefit from CRT. We evaluated whether a detailed analysis of QRS complex can improve prediction of CRT success. METHODS AND RESULTS: We studied 51 patients (67.3 + 9.5 years, 36 males) with classical indication to CRT. Twelve-lead electrocardiogram (ECG) (50 mm/s, 0.05 mV/mm) was obtained before and 3 months after CRT. The following ECG intervals were measured in leads V1 and V6: (i) total QRS duration; (ii) QRS onset-R wave peak; (iii) R wave peak-S wave peak (RS-V1 and RS-V6); (iv) S wave peak-QRS end; and (v) difference between QR in V6 and in V1. Patients were considered as responder when left ventricular ejection fraction (LVEF) increased by ≥5% and New York Heart Association class by ≥1 after 3 months of CRT. Of ECG intervals, only basal RS-V1 was longer in responders (n = 36) compared with non-responders (52.9 ± 11.8 vs. 44.0 ± 12.6 ms, P = 0.021). Among patients with RS-V1 ≥45 ms 83% responded to CRT vs. 33% of those with RS-V1 < 45 ms (P < 0.001). RS-V1 ≥ 45 ms was independently associated with response to CRT in multivariable analysis (odds ratio 9.8; P = 0.002). A reduction of RS-V1 ≥ 10 ms by CRT also significantly predicted clinical response. RS-V1 shortening correlated with improvement in LVEF (r = -0.45; P < 0.001) and in MS (r = 0.46; P < 0.001). CONCLUSION: Our data point out that RS-V1 interval and its changes with CRT may help to identify patients who are most likely to benefit from CRT.

Prevalence and clinical correlates of early repolarization and J wave in a large cohort of subjects without overt heart disease.

BACKGROUND: Recent studies have suggested that early repolarization (ER) is associated with increased risk of ventricular tachyarrhythmias. Early repolarization in these studies, however, was defined as J-wave (terminal QRS slurring or notching) or J-point elevation rather than typical ST-segment elevation (STE). Prevalence and characteristics of these different findings in the general population are poorly known. In this study, we assessed prevalence and correlates of STE typical of ER and of J wave in a large population of noncardiac subjects. METHODS: We prospectively collected electrocardiograms of 4176 consecutive subjects without heart disease at our hospital. RESULTS: Early repolarization was found in 84 subjects (2.0%) and J wave in 663 (15.9%). Among ER subjects, a J wave was present in 60 (71.4%). Variables independently associated with both ER and J wave included young age, male sex, and lower heart rate. There was no increased history of symptoms (palpitations and syncope) possibly related to arrhythmias in STE or J-wave subjects. CONCLUSIONS: Typical ER pattern and J wave are common in noncardiac subjects, particularly in young people, and are not associated with symptoms potentially related to arrhythmias.

T-wave alternans in apparently healthy subjects and in different subsets of patients with ischaemic heart disease.

AIMS: Microvolt T-wave alternans (TWA) predicts arrhythmic risk in patients with ischaemic heart disease (IHD). While TWA has widely been assessed by the spectral method, it has been poorly characterized in healthy people as well as in IHD patients by the modified moving average (MMA) method. METHODS AND RESULTS: We enrolled 729 consecutive subjects, referred for exercise stress test (EST). T-wave alternans was assessed by the MMA method, considering all 12 electrocardiogram (ECG) leads (TWA_tot) or the 6 ECG pre-cordial leads only (TWA_prec). Patients were divided into five groups: (i) no history of IHD and normal EST (Group 1); (ii) no history of IHD but positive EST (Group 2); (iii) ischaemic heart disease without any acute myocardial infarction [AMI (Group 3)]; (iv) old AMI (Group 4); (v) recent AMI (Group 5). T-wave alternans values >95th percentile of those measured in Group 1 were considered 'abnormal'. The 95th percentile of TWA values in Group 1 was 75 µV for TWA_tot and 65 µV for TWA_prec. T-wave alternans values and prevalence of abnormal TWA increased from Groups 1-2 to Group 5 (P< 0.00001 for both). Group 4 and Group 5, compared with Group 1, showed a significant higher prevalence of abnormal values of TWA_tot [odds ratio (OR) 1.70 (P= 0.002), and 2.07 (P= 0.01), respectively] and TWA_prec [OR 1.51 (P= 0.02) and 2.37 (P= 0.003), respectively] at multivariable analysis. In IHD patients EST-induced ischaemia did not influence TWA; in AMI patients, impaired left ventricular function was associated with higher TWA values. CONCLUSIONS: In healthy people, TWA_tot and TWA_prec were ≤75 and ≤65 µV, respectively, in 95% of subjects. In IHD patients TWA values were higher compared with healthy individuals; a history of AMI was independently associated with abnormal TWA values.

Effect of shift work on endothelial function in young cardiology trainees.

BACKGROUND: Long-term shift work (SW) is associated with an increase in cardiovascular disease (CVD). Previous studies have shown that prolonged SW is associated with endothelial dysfunction, suggesting that this abnormality may contribute to the SW-related increase in cardiovascular risk. The immediate effect of SW on endothelial function in healthy subjects, however, is unknown. DESIGN: We studied endothelial function and endothelium-independent function in 20 healthy specialty trainees in cardiology at our Institute, without any cardiovascular risk factor (27.3 ± 1.9 years, nine males), at two different times: (1) after a working night (WN), and (2) after a restful night (RN). The two test sessions were performed in a random sequence. METHODS: Endothelial function was assessed by measuring brachial artery dilation during post-ischaemic forearm hyperaemia (flow-mediated dilation, FMD). Endothelium-independent function in response to 25 µg of sublingual glyceryl trinitrate (nitrate-mediated dilation, NMD) was also assessed. RESULTS: FMD was 8.02 ± 1.4% and 8.56 ± 1.7% after WN and RN, respectively (p = 0.025), whereas NMD was 10.5 ± 2.1% and 10.4 ± 2.0% after WN and RN, respectively (p = 0.48). The difference in FMD between WN and RN was not influenced by the numbers of hours slept during WN (<4 vs >4 hours) and by the duration of involvement of specialty trainees in nocturnal work (<12 vs >12 months). CONCLUSIONS: Our study shows that in healthy medical residents, without any cardiovascular risk factor, FMD is slightly impaired after WN compared to RN. Disruption of physiological circadian neuro-humoral rhythm is likely to be responsible for this adverse vascular effect.