Biological organisms have intrinsic control systems that act in response to internal and external stimuli maintaining homeostasis. Human heart rate is not regular and varies in time and such variability, also known as heart rate variability (HRV), is not random. HRV depends upon organism's physiologic and/or pathologic state. Physicians are always interested in predicting patient's risk of developing major and life-threatening complications. Understanding biological signals behavior helps to characterize patient's state and might represent a step toward a better care. The main advantage of signals such as HRV indexes is that it can be calculated in real time in noninvasive manner, while all current biomarkers used in clinical practice are discrete and imply blood sample analysis. In this paper HRV linear and nonlinear indexes are reviewed and data from real patients are provided to show how these indexes might be used in clinical practice.

Although further studies investigating the relationship between hypomagnesaemia, depression, and treatment outcome are certainly necessary, we have hypothesized that hypomagnesaemia could be an epiphenomenic biochemical trait in less drug-responsive depressed patients. It is also plausible that lower Mg levels and hyperactive traits identify a biological subtype of patients with increased catecholaminergic functioning and a poorer response to aminergic drugs. Moreover, Mg depletion could partly account for the correlation between low Mg levels and poor outcome and this raises the question of Mg's possible therapeutic role in depression.

Mismatch negativity (MMN) is thought to reveal several abnormalities of cognitive functioning. Although depression often affects cognitive functioning, previous studies concerning MMN in depressed patients provided conflicting results. In recent reports, it has been suggested that depressed patients may show abnormal auditory response to regular auditory stimuli presented with at a relatively high intensity. We thus recorded acoustic MMN in 16 drug-free patients suffering from moderate depression and in 10 healthy subjects at 2 different stimulus intensities. Differences in MMN latency and amplitude between depressed patients and healthy subjects reached the significance level only for high intensity stimulation, and they were consistent with a dysfunction of frontal MMN subcomponents in depressed patients. This finding suggests that consistent MMN abnormalities can be observed in depressed patients by using high-intensity stimulation; moreover, it supports the hypothesis of disturbances of frontal networks in depression even in early stages of disease.

Helicobacter pylori virulent strains have been shown to affect cardiovascular diseases through molecular mimicry mechanisms. Silent autoimmune myocarditis has been hypothesized to be the cause of idiopathic dysrhythmias (IA). The aim of this study is to assess the prevalence of virulent H. pylori strains in patients affected by IA. In this study,54 patients (40 men, mean age 44 ± 17 years) affected by IA and 50 healthy subjects (34 men, mean age 45 ± 9) were evaluated. IA, defined as dysrhythmias with no evidence of other cardiac pathology, were either supraventricular (SVA, 23 patients; mean age 45 ± 15 years) or ventricular (VA, 31 patients; mean age 42 ± 18 years). H. pylori infection and gastrointestinal (GI) symptoms were evaluated. H. pylori strains expressing the cytotoxin-associated gene A (cagA) and the vacuolating-cytotoxin A (vacA) were also assessed through western blot. The prevalence of H. pylori is similar in IA patients and in controls (42 vs. 44%; p > 0.05); H. pylori infection is observed in 48 and 39% of the patients are affected by SVA and VA, respectively. The prevalence of CagA-positive strains is increased in IA patients compared to controls (65 vs. 42%; p < 0.01); similarly, the prevalence of VacA-positive strains is also increased in IA patients (74 vs. 46%; p < 0.006). Excluding belching, infected patients did not show any difference in GI symptoms, when compared to non-infected subjects. From this study it is concluded that there is an epidemiological link between CagA and VacA-positive H. pylori strains in IA patients.

Atrial Fibrillation management is still a matter for debate. Past research has largely been based on the outpatient setting in which patients are followed during ambulatory visits. Very little data exist on the optimal management of AF in the Emergency Department (ED). This study investigated which factors drive different AF treatments in the ED, describing their use in different hospitals. Finally, the efficacy of different strategies in terms of cardioversion in the ED was analyzed. Charts of patients treated for atrial fibrillation (AF) were collected in 6 EDs in a large metropolitan area over a 24-consecutive month period and were reviewed and analysed. Demographics, comorbidities, treatment strategy and ED outcome were collected. Inclusion criteria were symptom onset <3 weeks and stable hemodynamic conditions at presentation. A propensity score was used to adjust for baseline clinical characteristics and to compare the efficacy of different treatments. 3,085 patients were included in the analysis. Variables associated with a rhythm control strategy were onset of symptoms <48 h, age, dyspnea, palpitations, renal failure and the presence of a mechanical valve. Different EDs applied different strategies in terms of drugs used and the electrocardioversion rate, showing heterogeneity in AF management. Adjusting for the propensity score, electrocardioversion and antidysrhythmic drugs of class Ic were more effective than a wait-and-watch strategy in the ED. Despite international guidelines being respected, AF management is heterogeneous in different ED settings. A rhythm control strategy with electrocardioversion and Class Ic drugs is more effective than a wait-and watch approach during the ED visit. Further research, toward an evidence-based approach to the emergent management of AF in the ED, is still needed.