ATP - A friend with benefits.

Anti-tachycardia pacing (ATP) has gained widespread acceptance to treat ventricular tachyarrhythmias and prevent implantable defibrillator shocks. A 63-year-old lady with nonischemic cardiomyopathy underwent insertion of a primary prevention biventricular implantable cardioverter defibrillator (BIV-ICD). Post implant she was found to have recurrent episodes of atrioventricular nodal re-entry tachycardia (AVNRT) based on device electrograms. In this report, we describe the use of anti-tachycardia pacing to manage this tachycardia.

The bradykinin-cGMP-PKG pathway augments insulin sensitivity via upregulation of MAPK phosphatase-5 and inhibition of JNK.

Bradykinin (BK) promotes insulin sensitivity and glucose uptake in adipocytes and other cell types. We demonstrated that in rat adipocytes BK enhances insulin-stimulated glucose transport via endothelial nitric oxide synthase, nitric oxide (NO) generation, and decreased activity of the mitogen-activated protein kinase (MAPK) JNK (c-Jun NH2-terminal kinase). In endothelial cells, NO increases soluble guanylate cyclase (sGC) activity, which, in turn, activates protein kinase G (PKG) by increasing cGMP levels. In this study, we investigated whether BK acts via the sGC-cGMP-PKG pathway to inhibit the negative effects of JNK on insulin signaling and glucose uptake in rat adipocytes. BK augmented cGMP concentrations. The BK-induced enhancement of insulin-stimulated glucose uptake was mimicked by the sGC activator YC-1 and a cell-permeable cGMP analog, CPT-cGMP, and inhibited by the sGC inhibitor ODQ and the PKG inhibitor KT 5823. Transfection of dominant-negative PKG reduced the BK augmentation of insulin-induced Akt phosphorylation. The activation of JNK and ERK1/2 by insulin was attenuated by BK, which was mediated by the sGC-cGMP-PKG pathway. Whereas insulin-stimulated phosphorylation of upstream activators of JNK and ERK, i.e., MKK4 and MEK1/2, was unaffected, BK augmented insulin-mediated induction of MKP-5 mRNA and protein levels. Furthermore, zaprinast, a phosphodiesterase inhibitor, enhanced cGMP and MKP-5 and prolonged the action of BK. These data indicate that BK enhances insulin action by inhibition of negative feedback by JNK and ERK via upregulation of MKP-5, mediated by the sGC-cGMP-PKG signaling pathway.

An evaluation of Wikipedia as a resource for patient education in nephrology.

Wikipedia, a multilingual online encyclopedia, is a common starting point for patient medical searches. As its articles can be authored and edited by anyone worldwide, the credibility of the medical content of Wikipedia has been openly questioned. Wikipedia medical articles have also been criticized as too advanced for the general public. This study assesses the comprehensiveness, reliability, and readability of nephrology articles on Wikipedia. The International Statistical Classification of Diseases and Related problems, 10th Edition (ICD-10) diagnostic codes for nephrology (N00-N29.8) were used as a topic list to investigate the English Wikipedia database. Comprehensiveness was assessed by the proportion of ICD-10 codes that had corresponding articles. Reliability was measured by both the number of references per article and proportion of references from substantiated sources. Finally, readability was assessed using three validated indices (Flesch-Kincaid grade level, Automated readability index, and Flesch reading ease). Nephrology articles on Wikipedia were relatively comprehensive, with 70.5% of ICD-10 codes being represented. The articles were fairly reliable, with 7.1 ± 9.8 (mean ± SD) references per article, of which 59.7 ± 35.0% were substantiated references. Finally, all three readability indices determined that nephrology articles are written at a college level. Wikipedia is a comprehensive and fairly reliable medical resource for nephrology patients that is written at a college reading level. Accessibility of this information for the general public may be improved by hosting it at alternative Wikipedias targeted at a lower reading level, such as the Simple English Wikipedia.

Understanding the neuropsychiatric consequences associated with significant traumatic brain injury.

BACKGROUND: Traumatic brain injury (TBI) can give rise to a variety of neuropsychiatric syndromes. The objective of this review is to describe the neurobiological mechanisms that have been proposed to underlie many of these post-TBI syndromes, explore the utility of various investigative modalities and review the mechanisms of treatment available for them. METHODS: Six authors reviewed PubMed and Ovid literature that addressed TBI in the context of the neuropsychiatric sequelae, evaluation and management. RESULTS: Depressed mood, anxiety, impulsive/aggressive behaviour, impaired memory and sleep disturbances are among the most prevalent sequelae of severe TBI. Delirium, while less common, can also result from TBI, predisposing individuals to other psychiatric conditions, while psychosis, usually presenting with atypical features, is relatively rare. The evaluation of the brain following TBI has often relied on traditional structural imaging which, according to recent studies, is less sensitive than chemical and functional neuroimaging. A variety of pharmacologic and non-pharmacologic treatments have been investigated with varying degrees of success in managing the spectrum of post-TBI psychiatric illnesses. CONCLUSIONS: Neuropsychiatric sequelae are common following TBI. Several of these syndromes are amenable to treatment. Further investigations are required, however, to better understand the mechanistic aetiology of these conditions and the effectiveness of various therapeutic modalities.

Comparison of the major intraoperative and postoperative complications between unilateral and sequential bilateral total knee arthroplasty in a high-volume community hospital.

BACKGROUND: Total knee arthroplasty (TKA) is a common surgical treatment for arthritis. In the event of bilateral knee symptoms, a patient may elect for bilateral TKA (BTKA) under 1 anesthetic or 2 separate unilateral TKAs (UTKA). Controversy exists in the literature regarding the safety of BTKA versus UTKA. We compared the rate of major intraoperative and postoperative complications for BTKA versus UTKA at a high-volume community hospital. METHODS: We compared 373 patients who underwent BTKA with 966 who underwent UTKA between May 2008 and May 2011. Health records were used to determine patient characteristics and major intraoperative and postoperative complications. The BTKA and UTKA cohorts were matched for demographic characteristics and comorbidities with the exception of previous transient ischemic attack and previous knee surgery (UTKA > BTKA). RESULTS: Rates of intraoperative and postoperative complications, including cardiovascular, thromboembolic and neurologic complications; deep wound infections; and mortality, did not differ significantly between groups. Bilateral TKA was associated with a greater proportion of patients requiring blood transfusion than UTKA (29.8% v. 8.9%, p < 0.001). Among those transfused, there was no significant difference between the groups in the mean number of units required (1.72 ± 0.77 v. 1.53 ± 0.85 units, p = 0.68). CONCLUSION: Bilateral TKA was not associated with statistically greater rates of intraoperative and postoperative complications than UTKA, barring the proportion of patients requiring transfusion. Our results support the use of BTKA to treat bilateral knee arthritis in a high-volume community hospital setting.

CONTEXTE: La prothèse (ou arthroplastie) totale du genou (PTG) est un traitement chirurgical courant contre l'arthrite. Quand les 2 genoux sont atteints, le patient peut choisir entre une PTG bilatérale (PTGB), qui ne nécessitera qu'une seule anesthésie, ou 2 interventions unilatérales distinctes (PTGU). Dans la littérature, on ne semble pas s'entendre sur l'innocuité de la PTGB contre la PTGU. Nous avons comparé les taux de complications peropératoires et postopératoires majeures associées aux PTGB et aux PTGU dans un hôpital communautaire où s'effectue un volume élevé de telles interventions. MÉTHODES: Nous avons comparé 373 patients qui ont subi une PTGB à 966 qui ont subi une PTGU entre mai 2008 et mai 2011. Nous avons consulté les dossiers médicaux pour établir les caractéristiques des patients et relever les complications peropératoires et postopératoires majeures. Les cohortes soumises à la PTGB et à la PTBU ont été assorties en fonction des caractéristiques démographiques et des comorbidités, à l'exception des antécédents d'accidents ischémiques transitoires et d'interventions chirurgicales du genou (PTGU > PTGB). RÉSULTANTS: Les taux de complications peropératoires et postopératoires, y compris cardiovasculaires, thromboemboliques et neurologiques, les infections de plaies profondes et la mortalité n'ont pas varié significativement entre les groupes. Une proportion plus grande de patients soumis à la PTGB a nécessité une transfusion sanguine comparativement aux patients soumis à la PTGU (29,8 % c. 8,9 %, p < 0,001). Parmi les receveurs de transfusions, on n'a noté aucune différence significative entre les groupes quant au nombre moyen d'unités requises (1,72 ± 0,77 c. 1,53 ± 0,85 unité, p = 0,68). CONCLUSIONS: La PTGB n'a pas été associée à des taux statistiquement plus élevés de complications peropératoires et postopératoires comparativement à la PTGU, à l'exception de la proportion de patients ayant nécessité une transfusion. Nos résultats appuient le recours à la PTGB pour traiter l'arthrite bilatérale du genou dans le contexte d'un hôpital communautaire ou le volume de ces interventions est élevé.

A Practical Ambulatory Approach to Atrioventricular Block Secondary to Lyme Carditis.

Lyme carditis (LC) is a potentially reversible cause of complete atrioventricular (AV) dissociation that rarely requires a permanent pacemaker. The time to resolution is variable, sometimes requiring weeks, making a temporary permanent pacemaker (TPPM) a suitable bridge to recovery. We report on a 31-year-old man with serology-confirmed Lyme disease with complete heart block during the peak of the coronavirus disease 2019 pandemic. A TPPM was implanted and the patient was discharged the following day with regular follow-up in the ambulatory setting. Once 1:1 AV conduction was reestablished, the TPPM was removed. Our case demonstrates that the use of a TPPM for AV-dissociation secondary to LC is a safe and feasible strategy in select individuals which can minimize patient morbidity as well as hospital length of stay and overall health care costs.

Intra-His bundle block with Wenckebach phenomenon.

A 66-year-old lady presented with shortness of breath and a Wenckebach atrioventricular (AV) conduction pattern on the ECG. The electrophysiologic study showed split-His potentials and intra-Hisian Wenckebach. The case highlights the interesting finding of Wenckebach conduction in the His bundle.

The Natural History and Treatment of Cardiac Implantable Electronic Device Associated Pneumothorax-A 10-Year Single-Centre Experience.

BACKGROUND: Pneumothorax is a common complication of cardiac implantable electronic device (CIED) procedures. There is a paucity of data on the natural history and management of a CIED-associated pneumothorax. METHODS: This is a single-centre retrospective study of all consecutive patients with a CIED-associated pneumothorax between March 2010 and March 2020. Pneumothorax size was determined on all chest x-rays after device implantation and before chest tube insertion (if placed). Changes in pneumothorax size on serial chest x-rays were reported. Clinical outcomes in patients with a severe-sized pneumothorax treated with a chest tube were compared with those treated conservatively. RESULTS: A total of 86 CIED-associated pneumothoraxes were identified, with 55 (63.9%) patients having a pneumothorax severe in size. Thirty-seven patients with a severe pneumothorax received a chest tube, whereas 18 were managed conservatively. Chest tube use was associated with a higher rate of admission to hospital (100% vs 63%, P = 0.02) for patients undergoing outpatient procedure, longer length of stay (6.3 ± 3.9 vs 2.7 ± 2.9 days, P = 0.04), but fewer chest x-rays (1.9 ± 0.7 vs 4.1 ± 2.5, P = 0.002). CONCLUSION: An initial strategy of conservative management of a CIED-associated pneumothorax in select patients may be feasible and safe.

CONTEXTE: Le pneumothorax est une complication courante des interventions visant à mettre en place un dispositif cardiaque électronique implantable (DCEI). Il n'existe que très peu de données sur l'évolution naturelle et la prise en charge du pneumothorax lié à la pose d'un DCEI. MÉTHODOLOGIE: Nous avons étudié rétrospectivement les cas de patients ayant présenté un pneumothorax lié à un DCEI et traités consécutivement dans un même centre entre mars 2010 et mars 2020. La taille du pneumothorax a été déterminée dans toutes les cradiographies pulmonaires obtenues après la pose du DCEI et avant l'insertion d'un drain thoracique (le cas échéant). Les variations de la taille du pneumothorax mesurée sur les radiographies pulmonaires successives ont été rapportées. Les résultats cliniques observés chez les patients présentant un pneumothorax important traités par drainage thoracique ont été comparés à ceux de patients traités selon l'approche classique. RÉSULTATS: Au total, 86 cas de pneumothorax liés à un DCEI ont été relevés; 55 patients (63,9 %) présentaient un pneumothorax important. De ce nombre, 37 patients ont subi un drainage thoracique, tandis que les 18 autres ont été pris en charge selon l'approche classique. Le recours à un drain thoracique a été associé à un taux d'admission à l'hôpital plus élevé (100 % vs 63 %; p = 0,02) dans le cas des interventions ambulatoires et à une hospitalisation plus longue (6,3 ± 3,9 vs 2,7 ± 2,9 jours; p = 0,04), mais à un moins grand nombre de radiographies pulmonaires (1,9 ± 0,7 vs 4,1 ± 2,5; p = 0,002). CONCLUSION: Dans certains cas, il est possible et sûr d'avoir recours à une prise en charge initiale classique du pneumothorax lié à un DCEI.

A Matched Cohort Study of Patients With End-Stage Heart Failure from Anthracycline-Induced Cardiomyopathy Requiring Advanced Cardiac Support.

Anthracycline-induced cardiomyopathy (AIC) may progress to end-stage heart failure requiring mechanical circulatory support or orthotopic heart transplantation (OHT). Previous studies have described important clinical differences between AIC and nonischemic cardiomyopathy (NIC) cohorts requiring these advanced interventions. Therefore, we sought to extend this literature by comparing echocardiographic parameters, treatment strategies, and the prognosis between matched patients from these cohorts. This is a retrospective matched cohort study. All patients who received a ventricular assist device or OHT at a large Canadian center were reviewed (n = 421; 1988 to 2015) and subjects with clinical and pathologic evidence of AIC were included (n = 17, 4.0%). A comparison cohort with idiopathic NIC from the same database, matched 3:1 for age, gender, ethnicity, and year of heart failure onset was selected. The Mann-Whitney rank-sum and Fisher's exact tests were used for comparisons. Patients with AIC were predominantly women (70.6%) with heart failure diagnosed at age 40.2 ± 15.8 and 8.3 ± 8.9 years after anthracycline treatment. Compared with NIC, no differences were seen in co-morbidities, echocardiographic measures, the proportion of patients receiving a defibrillator, ventricular assist device, or OHT, the incidence of graft failure, and all-cause mortality. In contrast to other studies, AIC was not associated with a higher incidence of right ventricular dysfunction. A greater proportion of patients with AIC developed cancer (recurrence or new primary) post-OHT (21.4% vs 2.3%, p = 0.042). In conclusion, we demonstrate that when matched cohorts of patients with end-stage heart failure secondary to AIC and idiopathic NIC are compared, they are similar with respect to co-morbidities, degree of ventricular dysfunction, and advanced therapeutics used. The prognosis with OHT is also similar.