Successful Management of an Infected Implantable Cardioverter Defibrillator with Oral Antibiotics and without Removal of the Device

Infection of an implantable cardioverter defibrillator developed 2 weeks after implantation, presenting with fever, swelling, redness, and tenderness of the skin above the generator site. A cloxacillin resistant coagulase-negative staphylococcus was repeatedly cultured from the abdominal wall pocket fluid. The infection was successfully treated with a combination of two antibiotics, fusidic acid and rifampin, given orally for 3 months. Although the device was not removed, infection did not recur during a 24-month follow-up.     

Suppression of Atrial Tachyarrhythmias by Pacing

Pace‐Suppression of AF. Introduction: Treatment of atrial tachyarrhythmias (ATs) remains difficult in many patients. Accordingly, new therapeutic approaches for AT suppression are evaluated. Atrial pacing may prevent ATs by modifying the electrophysiologic conditions required for sustained ATs. Methods and Results: New pacing algorithms for prevention of AT are aimed at permanent overdrive suppression of arrhythmic activity, reduction of dispersion of atrial refractoriness produced by short‐long cycles, more aggressive overdrive pacing after spontaneous sinus conversion to prevent early reinitiation of ATs, and prevention of inadequate rate decay in patients with vagally induced ATs. AT prevention may be achieved by dedicated atrial pacing sites, e.g., pacing at the insertion of Bachmann's bundle or biatrial pacing, which compensates for interatrial conduction delay. Preexciting regions of critical conduction delay, pacing at the triangle of Koch or coronary sinus os, and dual‐site right atrial pacing have shown antiarrhythmic effects. Atrial preventive pacing and pharmacologic treatment may work synergistically in the concept of hybrid therapy. To prevent atrial electrical remodeling, early termination of AT seems desirable. This may be achieved by implanted devices that automatically detect ATs and provide atrial antitachycardia pacing for organized ATs. Initial studies showed that regular AT can automatically be terminated in approximately 50% of treated episodes. Conclusion: Pacing for prevention of AT and termination of organized AT episodes may become important steps within the concept of hybrid therapy of AT. However, their clinical efficacy and optimal patient selection remain to be evaluated in prospective, well‐designed clinical trials.     

Pacing to Prevent Atrial Fibrillation

Introduction: Pacing has been proposed as a nonpharmacologic treatment option to prevent atrial tachyarrhythmias (ATs) in drug-refractory patients. This article reviews the current state of pacing to prevent ATs.
Methods and Results: Different pacing modalities have been assessed with regard to their ability to prevent AT: conventional DDDR pacing with elevated lower rate limit, biatrial pacing, dual-site right atrial pacing, atrial septal pacing, and pacing with the use of dedicated pacing algorithms. Small studies suggest a benefit of conventional pacing for AT prevention in patients with bradycardia, but a randomized trial did not reveal any AT reduction by conventional pacing in patients without bradycardia. AT prevention by biatrial or dual-site right atrial pacing has been reported in small studies, but randomized trials did not show a clear benefit of these pacing techniques. Small studies showed a reduced AT recurrence rate in patients with septal pacing at the triangle of Koch or at Bachmann's bundle. Two large randomized trials with preventive pacing algorithms showed a significant AT reduction compared to conventional pacing, but this was not confirmed in four trials.
Conclusion: Pacing seems to be able to suppress ATs in a minority of patients; however, prospective identification of responders to different pacing modalities does not appear to be feasible at the present time. (J Cardiovasc Electrophysiol, Vol. 14, pp. S20-S26, September 2003, Suppl.)     

Cell attachment, growth characteristics and surface morphology of human upper-respiratory tract epithelium cultured on extracellular matrix

The advantageous utilization of nasal polypoid tissue as a source for human epithelial cells and the dramatic effect of extracellular matrix on growth and differentiation of these cells were demonstrated. Plating on extracellular matrix induced rapid, firm, cell attachment and flattening of the explants, promoted cell outgrowth as well as long-term survival of epithelial cells in primary cultures. Prominent ciliary activity was observed on the cells of the explant and on the cells in the outgrowth. These cells could be maintained on the extracellular matrix coated dishes for prolonged periods even after removal of the explant, with the cells in the outgrowth covering the region occupied by the removed explant. Prominent ciliary activity, which is considered one of the main criteria for cell viability and differentiation, continued also in the absence of the explant. The present system for cultivation of human upper respiratory tract epithelial cells on extracellular matrix might prove of value in analysing effects of chemotherapeutic agents that influence normal differentiation as well as the effects of viral and chemical carcinogens on these cells in human respiratory disease.     

Ethnic Differences in Atrial Fibrillation Identified Using Implanted Cardiac Devices

Ethnic Difference in Atrial Fibrillation Incidence. Introduction: Atrial fibrillation (AF) is suggested to be less common among black and Asian individuals, which could reflect bias in symptom reporting and access to care. In the Asymptomatic AF and Stroke Evaluation in Pacemaker Patients and the AF Reduction Atrial Pacing Trial (ASSERT), patients with hypertension but no history of AF had AF recorded via an implanted pacemaker or defibrillator, thus allowing both symptomatic and asymptomatic AF incidence to be determined without ascertainment bias. Methods and Results: The ASSERT enrolled 2,580 patients in 23 countries in North America, Europe, and Asia. AF was defined as device‐recorded AF episodes >190/min, lasting either for >6 minutes or >6 hours in duration. All ethnic groups with >50 patients were enrolled. Ethnic groups studied include Europeans (n = 1900), black Africans (n = 73), Chinese (n = 89), and Japanese (n = 105) patients. Compared to Europeans, black Africans had more risk factors for AF such as heart failure (27.8 vs 14.6%) and diabetes (41.7 vs 26.3%). At 2.5 years follow‐up, all 3 non‐European races had a lower incidence of AF (8.3%, 10.1%, and 9.5% vs 18.0%, respectively, for AF>6 minutes, P < 0.006). When adjusted for baseline difference, Chinese had a lower incidence of AF > 6 minutes (P < 0.007), and Japanese and black Africans had a lower incidence of AF > 6 hours (P < 0.04 and P = 0.057, respectively). Conclusions: Black Africans, Chinese, and Japanese had lower incidence of AF compared to Europeans. In the case of black Africans, this is despite an increased prevalence of AF risk factors. (J Cardiovasc Electrophysiol, Vol. 24, pp. 381‐387, April 2013)     

Susceptibility loci reported in genome‐wide association studies are associated with Crohn’s disease in Canadian children

Aliment Pharmacol Ther 31 , 1186–1191

Summary

Background Recent genome‐wide association studies based on adult and paediatric populations have implicated >30 genes/loci as susceptibility loci for Crohn’s disease (CD). Aims To investigate whether reported genes/loci were also associated with CD in Canadian children. Design and Methods A case‐control design was implemented at three paediatric gastroenterology clinics in Canada. Children ≤18 years of age with a confirmed diagnosis of CD were recruited along with controls. Single nucleotide polymorphisms (SNPs) in five genome‐wide association studies reported genes/loci were genotyped. Associations between individual SNPs and CD were examined. Results A total of 406 cases and 415 controls were studied. The mean (±s.d.) age of the cases was 12.3 (±3.2) years. Most cases were male (56.6%), had ileo‐colonic disease (L3 ± L4, 52.0%) and inflammatory behaviour (B1 ± p, 86.9%) at diagnosis. Allelic association analysis (two‐tailed) showed that three of the five targeted SNPs were significantly associated with overall susceptibility for CD (ZNF365, r10995271, P = 0.001; PTPN2, rs1893217, P = 0.005; STAT3, rs744166, P = 0.01). Associations with SNP rs4613763 in the PTGER4 locus were marginally nonsignificant (P = 0.07). The ZNF365 and STAT3 SNPs were predominantly associated with ileal disease with or without colonic involvement. Conclusion The identified susceptibility genes/loci for adult‐onset CD also confer risk for paediatric‐onset CD.