Clinical management of young competitive athletes with premature ventricular beats: a prospective cohort study

Funding Acknowledgements

Type of funding sources: None.

Background. Premature ventricular beats (PVBs) are not an unusual finding and their interpretation is sometimes challenging. Unfortunately, few data on the characteristics of PVBs that correlate with the risk of an underlying heart disease are available in athletes.

Objectives. The aim of this prospective study was to investigate the diagnostic and prognostic value of PVBs characteristics in competitive athletes.

Methods. From a cohort of 1,751 athletes evaluated at our sports cardiology centre, we enrolled 112 competitive athletes <40 years of age (mean age 21 ± 10 years) and with no known heart disease referred for PVBs. All athletes underwent physical examination, ECG, 12-lead ambulatory ECG monitoring, exercise testing, and echocardiography. Further investigations including cardiac magnetic resonance were performed for abnormal findings at first-line evaluation or for specific PVBs characteristics.

Results.  The majority (79%) of athletes exhibited monomorphic PVBs with a fascicular or infundibular pattern (common morphologies). A definitive diagnosis of cardiac disease was reached in 26 athletes (23% of the entire population) and correlated with uncommon PVBs morphology (p < 0.001) and arrhythmia complexity (p < 0.001). The number of PVBs/24-hour was lower in athletes with cardiac disease than in those with normal heart (p < 0.05). During the follow-up a spontaneous reduction of PVBs and no adverse events were observed.

Conclusions. Infundibular and fascicular PVBs were the most common morphologies observed in athletes with ventricular arrhythmias referred for cardiological evaluation. Morphology and complexity of PVBs, but not their number, predicted the probability of an underlying disease. Athletes with PVBs and negative investigation showed a good prognosis.

Abstract Figure.

Caldendrin and Calneurons-EF-Hand CaM-Like Calcium Sensors With Unique Features and Specialized Neuronal Functions

The calmodulin (CaM)-like Ca²⁺-sensor proteins caldendrin, calneuron-1 and -2 are members of the neuronal calcium-binding protein (nCaBP)-family, a family that evolved relatively late during vertebrate evolution. All three proteins are abundant in brain but show a strikingly different subcellular localization. Whereas caldendrin is enriched in the postsynaptic density (PSD), calneuron-1 and -2 accumulate at the trans-Golgi-network (TGN). Caldendrin exhibit a unique bipartite structure with a basic and proline-rich N-terminus while calneurons are the only EF-Hand CaM-like transmembrane proteins. These uncommon structural features come along with highly specialized functions of calneurons in Golgi-to-plasma-membrane trafficking and for caldendrin in actin-remodeling in dendritic spine synapses. In this review article, we will provide a synthesis of available data on the structure and biophysical properties of all three proteins. We will then discuss their cellular function with special emphasis on synaptic neurotransmission. Finally, we will summarize the evidence for a role of these proteins in neuropsychiatric disorders.

Transient Receptor Potential Ankyrin 1 Channels Modulate Inflammatory Response in Respiratory Cells from Patients with Cystic Fibrosis

Pseudomonas aeruginosa colonization, prominent inflammation with massive expression of the neutrophil chemokine IL-8, and luminal infiltrates of neutrophils are hallmarks of chronic lung disease in patients with cystic fibrosis (CF). The nociceptive transient receptor potential ankyrin (TRPA) 1 calcium channels have been recently found to be involved in nonneurogenic inflammation. Here, we investigate the role of TRPA1 in CF respiratory inflammatory models in vitro. Expression of TRPA1 was evaluated in CF lung tissue sections and cells by immunohistochemistry and immunofluorescence. Epithelial cell lines (A549, IB3-1, CuFi-1, CFBE41o^-) and primary cells from patients with CF were used to: (1) check TRPA1 function modulation, by Fura-2 calcium imaging; (2) down-modulate TRPA1 function and expression, by pharmacological inhibitors (HC-030031 and A-967079) and small interfering RNA silencing; and (3) assess the effect of TRPA1 down-modulation on expression and release of cytokines upon exposure to proinflammatory challenges, by quantitative RT-PCR and 27-protein Bioplex assay. TRPA1 channels are expressed in the CF pseudostratified columnar epithelium facing the bronchial lumina exposed to bacteria, where IL-8 is coexpressed. Inhibition of TRPA1 expression results in a relevant reduction of release of several cytokines, including IL-8 and the proinflammatory cytokines IL-1β and TNF-α, in CF primary bronchial epithelial cells exposed to P. aeruginosa and to the supernatant of mucopurulent material derived from the chronically infected airways of patients with CF. In conclusion, TRPA1 channels are involved in regulating the extent of airway inflammation driven by CF bronchial epithelial cells.

The peptide Phα1β, from spider venom, acts as a TRPA1 channel antagonist with antinociceptive effects in mice

BACKGROUND AND PURPOSE

Peptides from venomous animals have long been important for understanding pain mechanisms and for the discovery of pain treatments. Here, we hypothesized that Phα1β, a peptide from the venom of the armed spider Phoneutria nigriventer, produces analgesia by blocking the TRPA1 channel.

EXPERIMENTAL APPROACH

Cultured rat dorsal root ganglion (DRG) neurons, human fetal lung fibroblasts (IMR90) or HEK293 cells expressing the human TRPA1 (hTRPA1-HEK293), human TRPV1 (hTRPV1-HEK293) or human TRPV4 channels (hTRPV4-HEK293), were used for calcium imaging and electrophysiology. Nociceptive responses induced by TRPA1, TRPV1 or TRPV4 agonists or by bortezomib were investigated in mice.

KEY RESULTS

Phα1β selectively inhibited calcium responses and currents evoked by the TRPA1 agonist, allyl isothiocyanate (AITC), on hTRPA1-HEK293, IMR90 fibroblasts and DRG neurons. Phα1β did not affect calcium responses evoked by selective TRPV1 (capsaicin) or TRPV4 (GSK 1016790A) agonists on the various cell types. Intrathecal (i.t.) and intraplantar (i.pl.) administration of low doses of Phα1β (up to 300 pmol per paw) attenuated acute nociception and mechanical and cold hyperalgesia evoked by AITC (i.t. or i.pl.), without affecting responses produced by capsaicin or hypotonic solution. Notably, Phα1β abated the TRPA1-dependent neuropathic pain-like responses induced by bortezomib. In vitro and in vivo inhibition of TRPA1 by Phα1β was reproduced by a recombinant form of the peptide, CTK 01512-2.

CONCLUSIONS AND IMPLICATIONS

Phα1β and CTK 01512-2 selectively target TRPA1, but not other TRP channels. This specific action underlines the potential of Phα1β and CTK 01512-2 for pain treatment.

TRPA1 mediates trigeminal neuropathic pain in mice downstream of monocytes/macrophages and oxidative stress

Despite intense investigation, the mechanisms of the different forms of trigeminal neuropathic pain remain substantially unidentified. The transient receptor potential ankyrin 1 channel (encoded by TRPA1) has been reported to contribute to allodynia or hyperalgesia in some neuropathic pain models, including those produced by sciatic nerve constriction. However, the role of TRPA1 and the processes that cause trigeminal pain-like behaviours from nerve insult are poorly understood. The role of TRPA1, monocytes and macrophages, and oxidative stress in pain-like behaviour evoked by the constriction of the infraorbital nerve in mice were explored. C57BL/6 and wild-type (Trpa1(+/+)) mice that underwent constriction of the infraorbital nerve exhibited prolonged (20 days) non-evoked nociceptive behaviour and mechanical, cold and chemical hypersensitivity in comparison to sham-operated mice (P < 0.05-P < 0.001). Both genetic deletion of Trpa1 (Trpa1(-/-)) and pharmacological blockade (HC-030031 and A-967079) abrogated pain-like behaviours (both P < 0.001), which were abated by the antioxidant, α-lipoic acid, and the nicotinamide adenine dinucleotide phosphate oxidase inhibitor, apocynin (both P < 0.001). Nociception and hypersensitivity evoked by constriction of the infraorbital nerve was associated with intra- and perineural monocytic and macrophagic invasion and increased levels of oxidative stress by-products (hydrogen peroxide and 4-hydroxynonenal). Attenuation of monocyte/macrophage increase by systemic treatment with an antibody against the monocyte chemoattractant chemokine (C-C motif) ligand 2 (CCL2) or the macrophage-depleting agent, clodronate (both P < 0.05), was associated with reduced hydrogen peroxide and 4-hydroxynonenal perineural levels and pain-like behaviours (all P < 0.01), which were abated by perineural administration of HC-030031, α-lipoic acid or the anti-CCL2 antibody (all P < 0.001). The present findings propose that, in the constriction of the infraorbital nerve model of trigeminal neuropathic pain, pain-like behaviours are entirely mediated by the TRPA1 channel, targeted by increased oxidative stress by-products released from monocytes and macrophages clumping at the site of nerve injury.

The TRPA1 channel mediates the analgesic action of dipyrone and pyrazolone derivatives

BACKGROUND AND PURPOSE

Although still used by hundreds of millions of people worldwide, the mechanism of the analgesic action of the pyrazolone derivatives (PDs), dipyrone, propyphenazone and antipyrine remains unknown. The transient receptor potential ankyrin 1 (TRPA1) channel, expressed by nociceptors, is emerging as a major pain transduction pathway. We hypothesized that PDs target the TRPA1 channel and by this mechanism produce their analgesic effect.

EXPERIMENTAL APPROACH

Calcium responses and currents were studied in cultured TRPA1-expressing rodent dorsal root ganglion neurons and human cells. Acute nociception and mechanical hypersensitivity were investigated in naïve and genetically manipulated mice.

KEY RESULTS

Pyrazolone and PDs selectively inhibited calcium responses and currents in TRPA1-expressing cells and acute nocifensor responses in mice evoked by reactive channel agonists (allyl isothiocyanate, acrolein and H2 O2 ). In line with recent results obtained with TRPA1 antagonists and TRPA1 gene deletion, the two most largely used PDs, dipyrone and propyphenazone, attenuated TRPA1-mediated nociception and mechanical allodynia in models of inflammatory and neuropathic pain (formalin, carrageenan, partial sciatic nerve ligation and the chemotherapeutic drug, bortezomib). Notably, dipyrone and propyphenazone attenuated carrageenan-evoked mechanical allodynia, without affecting PGE2 levels. The main metabolites of PDs did not target TRPA1 and did not affect TRPA1-dependent nociception and allodynia.

CONCLUSIONS AND IMPLICATIONS

Evidence that in rodents the nociceptive/hyperalgesic effect produced by TRPA1 activation is blocked by PDs suggests that a similar pathway is attenuated by PDs in humans and that TRPA1 antagonists could be novel analgesics, devoid of the adverse haematological effects of PDs.

TRPA1 receptor stimulation by hydrogen peroxide is critical to trigger hyperalgesia and inflammation in a model of acute gout

Acute gout attacks produce severe joint pain and inflammation associated with monosodium urate (MSU) crystals leading to oxidative stress production. The transient potential receptor ankyrin 1 (TRPA1) is expressed by a subpopulation of peptidergic nociceptors and, via its activation by endogenous reactive oxygen species, including hydrogen peroxide (H2O2), contributes to pain and neurogenic inflammation. The aim of this study was to investigate the role of TRPA1 in hyperalgesia and inflammation in a model of acute gout attack in rodents. Inflammatory parameters and mechanical hyperalgesia were measured in male Wistar rats and in wild-type (Trpa1(+/+)) or TRPA1-deficient (Trpa1(-/-)) male mice. Animals received intra-articular (ia, ankle) injection of MSU. The role of TRPA1 was assessed by receptor antagonism, gene deletion or expression, sensory fiber defunctionalization, and calcitonin gene-related peptide (CGRP) release. We found that nociceptor defunctionalization, TRPA1 antagonist treatment (via ia or oral administration), and Trpa1 gene ablation abated hyperalgesia and inflammatory responses (edema, H2O2 generation, interleukin-1β release, and neutrophil infiltration) induced by ia MSU injection. In addition, we showed that MSU evoked generation of H2O2 in synovial tissue, which stimulated TRPA1 producing CGRP release and plasma protein extravasation. The MSU-elicited responses were also reduced by the H2O2-detoxifying enzyme catalase and the reducing agent dithiothreitol. TRPA1 activation by MSU challenge-generated H2O2 mediates the entire inflammatory response in an acute gout attack rodent model, thus strengthening the role of the TRPA1 receptor and H2O2 production as potential targets for treatment of acute gout attacks.

The TRPA1 channel in migraine mechanism and treatment

Migraine remains an elusive and poorly understood disease. The uncertainty is reflected by the currently unsatisfactory acute and prophylactic treatments for this disease. Genetic and pharmacological information points to the involvement of some transient receptor potential (TRP) channels in pain mechanisms. In particular, the TRP vanilloid 1 (TRPV1) and TRP ankyrin 1 (TRPA1) channels seem to play a major role in different models of pain diseases. Recent findings have underscored the possibility that TRP channels expressed in the nerve terminals of peptidergic nociceptors contribute to the migraine mechanism. Among this channel subset, TRPA1, a sensor of oxidative, nitrative and electrophilic stress, is activated by an unprecedented series of irritant and pain-provoking exogenous and endogenous agents, which release the pro-migraine peptide, calcitonin gene-related peptide, through this neuronal pathway. Some of the recently identified TRPA1 activators have long been known as migraine triggers. Furthermore, specific analgesic and antimigraine medicines have been shown to inhibit or desensitize TRPA1 channels. Thus, TRPA1 is emerging as a major contributing pathway in migraine and as a novel target for the development of drugs for pain and migraine treatment.

TRPA1 and other TRP channels in migraine

Ever since their identification, interest in the role of transient receptor potential (TRP) channels in health and disease has steadily increased. Robust evidence has underlined the role of TRP channels expressed in a subset of primary sensory neurons of the trigeminal ganglion to promote, by neuronal excitation, nociceptive responses, allodynia and hyperalgesia. In particular, the TRP vanilloid 1 (TRPV1) and the TRP ankyrin 1 (TRPA1) are expressed in nociceptive neurons, which also express the sensory neuropeptides, tachykinins, and calcitonin gene-related peptide (CGRP), which mediate neurogenic inflammatory responses. Of interest, CGRP released from the trigeminovascular network of neurons is currently recognized as a main contributing mechanism of migraine attack. The ability of TRPA1 to sense and to be activated by an unprecedented series of exogenous and endogenous reactive molecules has now been extensively documented. Several of the TRPA1 activators are also known as triggers of migraine attack. Thus, TRP channels, and particularly TRPA1, may be proposed as novel pathways in migraine pathophysiology and as possible new targets for its treatment.

Novel therapeutic strategy to prevent chemotherapy-induced persistent sensory neuropathy by TRPA1 blockade

Chemotherapy-induced peripheral neuropathy (CIPN) is a severe and painful adverse reaction of cancer treatment in patients that is little understood or treated. Cytotoxic drugs that cause CIPN exert their effects by increasing oxidative stress, which activates the ion channel TRPA1 expressed by nociceptors. In this study, we evaluated whether TRPA1 acted as a critical mediator of CIPN by bortezomib or oxaliplatin in a mouse model system. Bortezomib evoked a prolonged mechanical, cold, and selective chemical hypersensitivity (the latter against the TRPA1 agonist allyl isothiocyanate). This CIPN hypersensitivity phenotype that was stably established by bortezomib could be transiently reverted by systemic or local treatment with the TRPA1 antagonist HC-030031. A similar effect was produced by the oxidative stress scavenger α-lipoic acid. Notably, the CIPN phenotype was abolished completely in mice that were genetically deficient in TRPA1, highlighting its essential role. Administration of bortezomib or oxaliplatin, which also elicits TRPA1-dependent hypersensitivity, produced a rapid, transient increase in plasma of carboxy-methyl-lysine, a by-product of oxidative stress. Short-term systemic treatment with either HC-030031 or α-lipoic acid could completely prevent hypersensitivity if administered before the cytotoxic drug. Our findings highlight a key role for early activation/sensitization of TRPA1 by oxidative stress by-products in producing CIPN. Furthermore, they suggest prevention strategies for CIPN in patients through the use of early, short-term treatments with TRPA1 antagonists.

Transient receptor potential ankyrin 1 channel localized to non-neuronal airway cells promotes non-neurogenic inflammation

Background

The transient receptor potential ankyrin 1 (TRPA1) channel, localized to airway sensory nerves, has been proposed to mediate airway inflammation evoked by allergen and cigarette smoke (CS) in rodents, via a neurogenic mechanism. However the limited clinical evidence for the role of neurogenic inflammation in asthma or chronic obstructive pulmonary disease raises an alternative possibility that airway inflammation is promoted by non-neuronal TRPA1.

Methodology/Principal Findings

By using Real-Time PCR and calcium imaging, we found that cultured human airway cells, including fibroblasts, epithelial and smooth muscle cells express functional TRPA1 channels. By using immunohistochemistry, TRPA1 staining was observed in airway epithelial and smooth muscle cells in sections taken from human airways and lung, and from airways and lung of wild-type, but not TRPA1-deficient mice. In cultured human airway epithelial and smooth muscle cells and fibroblasts, acrolein and CS extract evoked IL-8 release, a response selectively reduced by TRPA1 antagonists. Capsaicin, agonist of the transient receptor potential vanilloid 1 (TRPV1), a channel co-expressed with TRPA1 by airway sensory nerves, and acrolein or CS (TRPA1 agonists), or the neuropeptide substance P (SP), which is released from sensory nerve terminals by capsaicin, acrolein or CS), produced neurogenic inflammation in mouse airways. However, only acrolein and CS, but not capsaicin or SP, released the keratinocyte chemoattractant (CXCL-1/KC, IL-8 analogue) in bronchoalveolar lavage (BAL) fluid of wild-type mice. This effect of TRPA1 agonists was attenuated by TRPA1 antagonism or in TRPA1-deficient mice, but not by pharmacological ablation of sensory nerves.

Conclusions

Our results demonstrate that, although either TRPV1 or TRPA1 activation causes airway neurogenic inflammation, solely TRPA1 activation orchestrates an additional inflammatory response which is not neurogenic. This finding suggests that non-neuronal TRPA1 in the airways is functional and potentially capable of contributing to inflammatory airway diseases.

TRPA1 and TRPV4 mediate paclitaxel-induced peripheral neuropathy in mice via a glutathione-sensitive mechanism

Paclitaxel produces a sensory neuropathy, characterized by mechanical and cold hypersensitivity, which are abated by antioxidants. The transient receptor potential vanilloid 4 (TRPV4) channel has been reported to contribute to paclitaxel-evoked allodynia in rodents. We recently showed that TRP ankyrin 1 (TRPA1) channel mediates oxaliplatin-evoked cold and mechanical allodynia, and the drug targets TRPA1 via generation of oxidative stress. Here, we have explored whether TRPA1 activation contributes to paclitaxel-induced mechanical and cold hypersensitivity and whether this activation is mediated by oxidative stress generation. Paclitaxel-evoked mechanical allodynia was reduced partially by the TRPA1 antagonist, HC-030031, and the TRPV4 antagonist, HC-067047, and was completely abated by the combination of the two antagonists. The reduced paclitaxel-evoked mechanical allodynia, observed in TRPA1-deficient mice, was completely abolished when mice were treated with HC-067047. Cold allodynia was abated completely by HC-030031 and in TRPA1-deficient mice. Exposure to paclitaxel of slices of mouse esophagus released the sensory neuropeptide, calcitonin gene-related peptide (CGRP). This effect was abolished by capsaicin desensitization and in calcium-free medium (indicating neurosecretion from sensory nerve terminals), partially reduced by either HC-030031 or HC-067047, and completely abated in the presence of glutathione (GSH). Finally, the reduced CGRP release, observed in esophageal slices of TRPA1-deficient mice, was further inhibited by GSH. Paclitaxel via oxygen radical formation targets TRPA1 and TRPV4, and both channels are key for the delayed development of mechanical allodynia. Cold allodynia is, however, entirely dependent on TRPA1.

Work-related stress and bullying: gender differences and forensic medicine issues in the diagnostic procedure

BACKGROUND

The attention of international agencies and scientific community on bullying and work-related stress is increasing. This study describes the gender differences found in victims of bullying and work-related stress in an Italian case series and analyzes the critical issues in the diagnostic workup.

METHODS

Between 2001 and 2009 we examined 345 outpatients (148 males, 197 females; mean age: 41 ± 10.49) for suspected psychopathological work-related problems. Diagnosis of bullying was established using international criteria (ICD-10 and DSM-IV).

RESULTS

After interdisciplinary diagnostic evaluation (Occupational Medicine Unit, Psychology and Psychiatry Service), the diagnosis of bullying was formulated in 35 subjects, 12 males and 23 females (2 cases of Post-Traumatic Stress Disorder and 33 of Adjustment Disorder). Fifty-four (20 males, 34 females) suffered from work-related anxiety, while work-unrelated Adjustment Disorder and other psychiatric disorders were diagnosed in 7 and 112 subjects, respectively. Women between 34 and 45 years showed a high prevalence (65%) of "mobbing syndrome" or other work-related stress disorders.

CONCLUSIONS

At work, women are more subject to harassment (for personal aspects related to emotional and relational factors) than men. The knowledge of the phenomenon is an essential requisite to contrast bullying; prevention can be carried out only through effective information and training of workers and employers, who have the legal obligation to preserve the integrity of the mental and physical status of their employees during work.

S-100 protein and neuron-specific enolase as markers of subclinical cerebral damage after cardiac surgery: preliminary observation of a 6-month follow-up study

Cerebral damage remains one of the hazards related to cardiac surgery with cardiopulmonary bypass. The use of biochemical markers of cerebral injury may be of practical value. We investigated the plasma release patterns of S-100 protein and neuron-specific enolase (NSE) during the intervention and their relationship with the development of neuropsychological deficits assessed 6 months after the intervention in 16 patients undergoing elective cardiac surgery with cardiopulmonary bypass. Both S-100 and NSE significantly increased peri- and postoperatively. Significant correlations were found between values measured at several time points and impaired performance in a few tests at the 6-month follow-up. A stratification into two age subgroups led to the hypothesis that age might have a confounding or a modifying effect on the association between S-100 and NSE levels, and cognitive impairment.

Cardiac troponin I and Q-wave perioperative myocardial infarction after coronary artery bypass surgery

OBJECTIVE

To monitor cardiac troponin I (cTnI), a newly developed biochemical index for cardiac damage, in patients during and after coronary artery bypass surgery (CABS) to determine whether the measurement of the serum levels of this marker could be of value in formulating an early diagnosis of Q-wave perioperative myocardial infarction (PMI).

DESIGN

Prospective study with sequential measurements of biological markers in a selected surgical patient group.

SETTING

University research laboratory and general university hospital (Cardiac Surgery Unit and Anesthesiology and Reanimation Unit).

PATIENTS

Forty-two patients undergoing elective CABS without concomitant valvular replacement.

INTERVENTIONS

There were no interventions required for this study. However, patients entered into the study had CABS, sequential arterial blood samples, ECG recordings, and echocardiograms performed.

MEASUREMENTS AND MAIN RESULTS

Pre-, intra-, and postoperative (up to 48 hrs) measurements of cardiac troponin I, MB-CK, and total creatine kinase, as well as serial electrocardiograms and echocardiograms. Perioperative infarction was assessed as the development of new persistent regional wall motion abnormalities in echocardiography together with electrocardiographic alterations and MB-CK increases. Eight patients had Q-wave PMI. All PMI patients had elevated peak cTnI values (all >9.2 ng/mL), whereas the 34 nonPMI patients had peak values <9.0 ng/mL; therefore, sensitivity and specificity (with a 9.0 ng/mL cut-off value) are 100%. MB-CK measurement peak values did not demonstrate such a high specificity and sensitivity.

CONCLUSIONS

Because of its high specificity and sensitivity, serial measurements of cTnI provide a rapid and accurate method for confirming or excluding the diagnosis of perioperative myocardial injury. cTnI evaluation can therefore be used both as an independent prognostic marker for patients undergoing cardiac surgery and as a powerful tool for detecting smaller PMIs often missed with standard PMI diagnostic criteria.