Minimal configuration of body surface potential mapping for discrimination of left versus right dominant frequencies during atrial fibrillation

BACKGROUND

Ablation of drivers maintaining atrial fibrillation (AF) has been demonstrated as an effective therapy. Drivers in the form of rapidly activated atrial regions can be noninvasively localized to either left or right atria (LA, RA) with body surface potential mapping (BSPM) systems. This study quantifies the accuracy of dominant frequency (DF) measurements from reduced-leads BSPM systems and assesses the minimal configuration required for ablation guidance.

METHODS

Nine uniformly distributed lead sets of eight to 66 electrodes were evaluated. BSPM signals were registered simultaneously with intracardiac electrocardiograms (EGMs) in 16 AF patients. DF activity was analyzed on the surface potentials for the nine leads configurations, and the noninvasive measures were compared with the EGM recordings.

RESULTS

Surface DF measurements presented similar values than panoramic invasive EGM recordings, showing the highest DF regions in corresponding locations. The noninvasive DFs measures had a high correlation with the invasive discrete recordings; they presented a deviation of <0.5 Hz for the highest DF and a correlation coefficient of >0.8 for leads configurations with 12 or more electrodes.

CONCLUSIONS

Reduced-leads BSPM systems enable noninvasive discrimination between LA versus RA DFs with similar results as higher-resolution 66-leads system. Our findings demonstrate the possible incorporation of simplified BSPM systems into clinical planning procedures for AF ablation.

Review: Application of Pulsed Electric Fields in Egg and Egg Derivatives

This work overviews works published on the application of pulsed electric fields (PEF) in egg and egg derivatives, grouped by subject, and arranged chronologically in terms of the factor studied (microorganisms, quality aspects, shelf life and structural changes in gel formation properties). The inactivation of microorganisms by PEF in egg is very considerable, 3.5 decimal reductions in egg white were achieved by PEF in Salmonella enteritidis, 5.5 log reductions of Listeria innocua by means of a synergistic effect of PEF and nisin in liquid whole egg, and 5.6 log reductions of Escherichia coli in beaten fresh liquid egg by PEF treatment applied continuously or discontinuously in five steps. The shelf life of PEF-treated fresh liquid egg was extended to 4 weeks in refrigeration, and quality (colour, viscosity and sensory attributes) was not affected by PEF treatment. PEF treatment did not cause notable changes in proteins in a solution of ovalbumin and dialysed fresh egg white. However, some structural changes and functional modifications were observed in fresh egg white as a result of PEF treatment. The texture and microstructure of gels were affected by the application of PEF, and therefore PEF treatment conditions in egg white must be optimised to minimise possible modifications.

[Confusion as a presentation symptom of pseudomigraine with pleocytosis in a paediatric patient]

Transient headache and neurological deficits with cerebrospinal fluid lymphocytic pleocytosis (Handl) syndrome is a rare condition of unknown origin that is characterized by episodes of severe headache, transient neurological deficits that recur over less than 3 months, and lymphocytic pleocytosis in CSF. We report the case of a 14 year-old girl who presented with headache and vomiting that lasted 4 days, later combined with a clinical presentation of confusion, with a decrease in the level of consciousness, aphasia, peripheral facial paralysis, ataxia and fever for 24 hours. CSF analysis showed pleocytosis (110 cells/ml) and proteinorrachia (87 mg/dl). Electroencephalogram in the acute time showed generalized slowing, and later a focal slowing in the left hemisphere. She suffered 7 episodes of migraine (severe headache and vomiting) in the following two months, remaining asymptomatic thereafter. This is the first pediatric case published in the literature that presents with an agitated and/or confused state. This condition must be considered in the differential diagnosis of patients with headache and acute altered level of consciousness, in order to avoid prolonged treatments or unnecessary invasive testing.

Comparison of phalangeal bone mineral content and density between the dominant and non-dominant sides

OBJECTIVES

Compared to the non-dominant side, higher bone mineral content (BMC) and density (BMD) have been demonstrated in the forearm bones in the dominant side. Clinicians are compelled to scan the dominant side when deformities or artifacts are found in the non-dominant side. This study was done to evaluate the differences in phalangeal BMC and BMD, measured using accuDXA, between the dominant and non-dominant hands. Design and participants A group of 333 subjects, comprising 267 healthy volunteers (185 women and 82 men) and 66 women with rheumatoid arthritis. Phalangeal BMD and BMC, were measured using accuDEXA, both in the non-dominant and dominant hands. Main results BMC and BMD showed strong correlations between the two sides (r = 0.95, p < 0.001 for both). Compared to the non-dominant side, dominant side BMC was 5% higher (mean values =1.54 and 1.47, mean difference = 0.064, 95% CI for the mean difference = 0.048-0.081 g, p < 0.001) and BMD was 4% higher (mean values = 0.480 and 0.463, mean difference = 0.018, 95% CI for the mean difference = 0.014-0.021 g/cm2, p < 0.001). In the subgroup analysis, percentage differences of BMD between the two sides were found to be similar among men (n=82), women (n=251), people below 50 years (n=24), people above 50 years (n=122) and also among patients with rheumatoid arthritis (n=66). Conclusions When the non-dominant hand is not suitable for scanning, the clinician should consider scanning the dominant hand instead. However, the differences in BMD between the two hands should be taken into consideration when interpreting results.

[Acute necrotizing esophagitis in an unstable patient]

Acute necrotizing esophagitis or black esophagus is a rare affection, described in the medical literature since 1990. Although its mechanism is not fully understood, ischemic compromise appears to be the fundamental physiopathological factor. When acute necrotizing esophagitis is found in the endoscopic study of an upper digestive haemorrhage, the prognosis is good. We present a case in which diagnosis of black esophagus was an endoscopic finding, secondary to a situation of underlying hemodynamic instability, with a fatal outcome.

Organization of risk analysis in the EU and the new EU food regulation

Given the scope and magnitude of the food supply in modern societies, there is no way to ensure that all foods are kept free from potential sources of contamination. Instead, food safety is enhanced by systematically concentrating upon minimizing opportunities for contamination at every point from food production and processing to distribution, preparation, and consumption. Although previous advances, such as pasteurization and refrigeration, and contemporary improvements in hazard analysis and control have significantly improved the safety of the food supply, foodborne disease remains a major cause of morbidity and mortality. Consequently, the food policy of the European Union and member states must reach the highest food safety standards in order to reduce the incidence of the illness produced by consumption of foods. To reach this goal, the new food regulation is in force since 2002 with the amendment through the hygiene package, which is in force since 2006. Risk Analysis forms the foundation on which food safety policy is based and an important part is aimed at microbiolgogical contamination. Additionally a European Food Safety Authority was established to carry out risk assessment and communication of food safety issues. At the same time, member states have created their own Food Safety Agencies working closely with the European Food Safety Authority. In this work, a description of the structure and work of the European Food Safety Authority and as an example the Spanish Food Safety Agency as well as key elements of the new regulation with special respect to the hygiene package is given.