Temperature fluctuations along food supply chain: A dynamic and stochastic predictive approach to establish the best temperature value in challenge tests for Listeria monocytogenes.

This study aims to evaluate the behaviour of Listeria monocytogenes under fluctuating temperature comparing the efficacy of deterministic and stochastic methods for its prediction. In the first part of the study, a strain of L. monocytogenes was maintained at two different fluctuating temperature regimes both from 2 to 8°C and regularly sampled for the quantitative determination. The first temperature regime lasted 204 hours with a fluctuation length of 12 hours whereas the second lasted 167 hours with a fluctuation length of 24 hours. A dynamic predictive model was implemented for the reproduction of the observed data. Model resolution has been carried out by using values of the recorded temperature as well as the value of the mean temperature, the kinetic mean temperature, the 75th and 95th percentile of the temperature. A stochastic resolution was also performed considering the mean temperature and Standard Deviation as stochastic variable. In the second part of the study, a temperature mean curve was constructed by monitoring temperature of 8 refrigerated conveyances, 10 display cabinet and 15 domestic refrigerators. This curve was used to obtain predictive scenarios for L. monocytogenes based on the above and also considering temperature regime suggested by the EURL Lm TECHNICAL GUIDANCE DOCUMENT on challenge tests and durability studies for assessing shelf-life of ready-to-eat foods related to Listeria monocytogenes (Version 4 of 1 July 2021). All predicted behaviours were compared to the observed ones through the Root Mean Squared Error. Firstly, dynamic predictive model as well as the stochastic one, provided the best level of reproducibility of the observed data. The kinetic mean temperature reproduced the observed data better than the mean temperature for the 12 hoursregime while for the 24 hours-regime was the opposite. The 75th and 95th percentile overestimated the observed growths. Secondary, predictions obtained with the mean temperature, kinetic temperature and stochastic approach well fitted the observed data. The 75th and 95th percentile of Temperature and the "Eurl LM" temperature regimes overestimated the observed prediction. Dynamic approach as well as the stochastic one allowed to obtain the lowest values of Root Mean Squared Error. The mean temperature and kinetic mean temperature appeared the most representative values in a deterministic "single-point" approach.

Usefulness of nonlinear analysis of ECG signals for prediction of inducibility of sustained ventricular tachycardia by programmed ventricular stimulation in patients with complex spontaneous ventricular arrhythmias.

INTRODUCTION: The aim of our study was to assess the effectiveness of the nonlinear analysis (NLA) of ECG in predicting the results of invasive electrophysiologic study (EPS) in patients with ventricular arrhythmias. METHODS: We evaluated 25 patients with history of cardiac arrest, syncope, sustained, or nonsustained ventricular tachycardia (VT). All patients underwent electrophysiologic study (EPS) and nonlinear analysis (NLA) of ECG. The study group was compared with a control group of 25 healthy subjects, in order to define the normal range of NLA. ECG was processed in order to obtain numerical values, which were analyzed by nonlinear mathematical functions. Patients were classified through the application of a clustering procedure to the whole set of functions, and the correlation between the results of nonlinear analysis of ECG and EPS was tested. RESULTS: NLA assigned all patients with negative EPS to the same class of healthy subjects, whereas the patients in whom VT was inducible had been correctly and clearly isolated into a separate cluster. In our study, the result of NLA with application of the clustering technique was significantly correlated to that of EPS (P < 0.001), and was able to predict the result of EPS, with a negative predictive value of 100% and a positive predictive value of 100%. CONCLUSIONS: NLA can predict the results of EPS with good negative and positive predictive value. However, further studies are needed in order to verify the usefulness of this noninvasive tool for sudden death risk stratification in patients with ventricular arrhythmias.

[Antithrombotic prevention in atrial fibrillation: the new anticoagulant drugs]. / I nuovi anticoagulanti nella profilassi antitrombotica della fibrillazione atriale.

Thromboembolic events are the most dangerous complications in patients with atrial fibrillation, affecting the central nervous system in 93% of cases. Vitamin K antagonists have been in clinical use since the '50s for the prevention of thromboembolism. Although effective, vitamin K antagonists have several limitations that render them difficult to administer, which have prompted the need for new antithrombotic strategies. The new class of oral anti-IIa and anti-Xa agents appears to be a promising alternative to overcome these limitations.

[Provocative tests and electrophysiological study in athletes]. / Test provocativi e studio elettrofisiologico nello sportivo.

Provocative tests can be divided into three main categories: first-level or screening tests, consisting basically of step test, which all athletes undergo during pre-participation screening; second-level tests, which include exercise test (simple or cardiopulmonary), performed on the basis of specific clinical indications or for the assessment of functional capacity; and third-level tests, consisting of complex methods such as myocardial scintigraphy and stress echo (or exercise echo), which are performed in subjects adequately selected according to clinical characteristics or to the results of first- and second-level tests. The electrophysiological endocavitary study has specific indications in sustained or frequent ventricular arrhythmias, while it is not useful in diagnostic evaluation of athletes with supraventricular arrhythmias, where it has been replaced in most cases by transesophageal electrophysiological study.

[Cardiovascular complications of chemotherapy]. / Complicanze cardiovascolari della terapia antineoplastica.

In the last decades, oncological therapy has changed the natural history of many types of cancer, which can now be considered curable or as chronic or slowly progressive diseases. It is well known that chemotherapy and radiotherapy may induce cardiotoxicity. Anthracyclines are among the most active antineoplastic agents, and their cardiac effects have been known for a long time. In addition, there is an emerging role for potential cardiovascular effects of other chemotherapy drugs such as taxanes, antimetabolites (capecitabine) as well as targeted agents (monoclonal antibody trastuzumab and bevacizumab and the tyrosin-kinase inhibitor sunitinib). Patient treated with chemotherapy are at higher risk of cardiovascular events than the general population, so that having undergone chemotherapy may be considered as a novel cardiovascular risk factor. This review briefly summarizes the most important cardiovascular toxicities caused by antineoplastic pharmacological treatment and how cardiologists, oncologists and general practitioners should approach cancer patients while on treatment or during follow-up to prevent or manage cardiovascular events.

[Cryoablation: patient selection and current results]. / La crioablazione: selezione dei pazienti ed attuali risultati.

During the last years, cyoablation of atrial fibrillation has become a widely used method for pulmonary vein isolation. This evolution in the use of cryoenergy has been largely justified by the reduction in complications that occurs with radiofrequency energy (pulmonary vein stenosis and atrial-esophageal fistula), in the use of three-dimensional navigation technology, and hence procedural costs. The purpose of this paper is to evaluate the results of this new technology and its safety in terms of its risk-to-benefit profile.

[Idiopathic ventricular tachycardia: clinical characteristics and management]. / La tachicardia ventricolare idiopatica: significato clinico e terapia.

Outflow tract ventricular tachycardia (VT) is the most common form of idiopathic VT in clinical practice. The correct differential diagnosis with VTs caused by structural heart diseases (particularly arrhythmogenic right ventricular cardiomyopathy) is extremely challenging for the cardiologist. When correctly diagnosed, outflow tract VTs have a favorable prognosis in the majority of patients. At present, technical advancements and improved clinical experience in transcatheter ablation procedures may offer a definite therapy to an increasing number of patients with an acceptable complication rate.

Microvolt T-wave alternans for risk stratification in athletes with ventricular arrhythmias: correlation with programmed ventricular stimulation.

BACKGROUND: Aim of our study is to evaluate the role of T-wave alternans (TWA) to stratify the risk of sudden cardiac death in athletes (Ath) with complex ventricular arrhythmias (VA), and to document a possible correlation between TWA and electrophysiological testing (EPS) results. METHODS: We studied 85 Ath with VA (61 M, mean age 32 +/- 11 years). In all cases a cardiological evaluation was performed, including TWA and EPS. The patients were evaluated during a follow-up of 30 +/- 21 months. The end point was the occurrence of sudden death (SD) or malignant ventricular tachyarrhythmias (VT). RESULTS: TWA was negative in 57 Ath (68%), positive in 15 (18%) and indeterminate in 13 (14%). All subjects with negative TWA did not show induction of VT at EPS, with significant correlation between negative TWA and negative EPS (P < 0.001). All Ath with positive TWA also had VT induced by a EPS, with significant correlation (P < 0.001). By contrast, our data did not show significant correlation between indeterminate TWA and positive or negative EPS. However, there was significant correlation between abnormal TWA test (positive + indeterminate) and inducibility of VT at EPS (P < 0.001). During follow-up we observed a significant difference in end point occurrence (VT or SD) between Ath with negative or abnormal TWA and between Ath with negative or positive EPS. CONCLUSION: TWA confirm its role as a simple and noninvasive test, and it seems useful for prognostic stratification of Ath with VA.

[Current limitations and new perspectives in the diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia]. / L'iter diagnostico della cardiomiopatia aritmogena del ventricolo destro: limiti attuali e nuove prospettive.

Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is a genetic cardiomyopathy characterized by ventricular arrhythmias and structural abnormalities of the right ventricle. In ARVC/D there is a progressive replacement of right ventricular myocardium with fatty and fibrous tissue and ventricular arrhythmias of right ventricular origin. The precise prevalence of ARVC/D has been estimated to vary between 1 in 1000 to 1 in 5000 of the general population. ARVC accounts for approximately 3-10% of sudden deaths in young people under the age of 65 years. The purpose of this paper is to review the current knowledge of ARVC/D and its management. Particular attention will be focused on some of the recent advances in the understanding of the genetic basis of ARVC/D. Increasing evidence suggests that ARVC/D is a disease of desmosomal dysfunction. Attention will also be focused on the new and somewhat controversial concept that ARVC/D may present primarily as a left ventricular disease. In our experience ARVC/D typically presents as a right ventricular disease, unless a patient has advanced disease. Diagnosis of ARVC/D is challenging and requires a comprehensive evaluation with both non-invasive and invasive testing.

Ventricular arrhythmias in competitive athletes: risk stratification with T-wave alternans.

INTRODUCTION: Aim of our study is to evaluate the role of TWA to stratify the risk of sudden cardiac death in athletes (Ath) with complex ventricular arrhythmias (VA), and to document a possible correlation between TWA and electrophysiological testing (EES) results. METHODS: We studied 43 Ath with VA (31 M, mean age 34 ± 12 years). In all cases a cardiological evaluation was performed, including TWA and EES. The patients were evaluated during a follow-up of 25 ± 22 months. The end-point was the occurrence of sudden death or malignant ventricular tachyarrhythmias (VT). RESULTS: TWA was negative in 28 Ath (65%), positive in 8 (19%) and indeterminate in 7 (16%). All subjects with negative TWA did not show induction of VT at EES, with significant correlation between negative TWA and negative EES (p<0.001). All Ath with positive TWA also had VT induced by a EES, but without significant correlation between positive TWA and positive EES. In 2 Ath with undetermined TWA (29%) VT were induced at EES. Our data did not show significant correlation between indeterminate TWA and positive or negative EES. However, logistic regression analysis showed significant correlation between abnormal TWA test (positive or indeterminate) and inducibility of VT at EES (p<0.001). During follow-up we observed a significant difference in end-point occurrence between Ath with negative or positive TWA and between Ath with negative or positive EES. CONCLUSION: TWA confirm its role as a simple and non-invasive test, and it seems useful for prognostic stratification of Ath with VA.