Ablation of Atrial Fibrillation Using an Irrigated‐Tip Catheter: Open or Closed?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91175/1/j.1540-8159.2012.03333.x.pd

A review of the current place of glycopeptides in turkish medical practice

AbstractBackground: Glycopeptide antibiotics are considered by many investigators to be the last resort in the treatment of gram-positive bacterial infections.Objective: The aim of this review was to assess the place of glycopeptides in the treatment of common gram-positive bacteria in accordance with the current epidemiologic data in Turkey.Methods: A search of both the English- and Turkish-language literature indexed on MEDLINE, Ulakbim (Turkey), and Pleksus (Turkey) was performed using the terms: vancomycin, teicoplanin, and glycopeptides, or their Turkish-language counterparts. The complete texts of the articles found in these databases were obtained from the electronic library of Gulhane Medical Academy, Ankara, Turkey. Articles from regional journals, without the support of an electronic format, were obtained by direct communication. Articles of interest were those based on studies occurring in Turkish populations, with special consideration given to publications in press after 2002.Results: Staphylococci were the most frequent gram-positive pathogens encountered in Turkish hospitals. Studies have found that ∼74% of strains were Staphylococcus aureus and the remaining strains were coagulase-negative staphylococci (CoNS). Overall methicillin resistance in staphylococci was reported as ∼60%. In Turkey, S aureus was one of the most common infectious agents found inside hospitals and is deemed a growing threat in the community. While the rate of methicillin resistance in community-acquired isolates is ∼4%, the data from hospitals suggest that reduced resistance comprises most of the isolates. In the studies reviewed, older quinolones like ciprofloxacin and ofloxacin seem to be ineffective in nearly half of the S aureus isolates. Alternatives like rifampicin, gentamicin, tetracycline, trimethoprim/sulfamethoxazole (TMP/SMX), clindamycin, and erythromycin have had substantial resistance profiles in >50% of the strains. In recent Turkish studies, in vitro profiles of linezolid, quinupristin/dalfopristin (QD), and daptomycin have had positive results. As in the S aureus isolates, resistance trends have been observed in the CoNS group of pathogens. The possible use of β-lactams seems restricted, and alternative approaches have become necessary. Quinolones, gentamicin, tetracycline, TMP/SMX, clindamycin, and erythromycin have resistance profiles of >50%. Although glycopeptide resistance was not detected, the frequency of heterogenous vancomycin-intermediate S aureus, a precursor to future resistance, was 13% in 1 study. Current studies in Turkey have found that Enterococcus faecalis comprises three quarters of enterococci while the rest are comprised of Enterococcus faecium. Initial studies performed with linezolid, QD, and daptomycin suggest that these drugs might be effective alternatives for future enterococcal infections that may have high glycopeptide resistance. Approximately 8% of the Streptococcus pneumoniae strains had high-level resistance in Turkey. However, 10 million units of crystallized penicillin or 3 g of oral amoxicillin maintains the optimum treatment of pneumococcal infections outside the central nervous system (CNS). Resistance profiles in third-generation cephalosporins in Turkey range between 2% and 2.5%.Conclusions: In Turkey, a review of the existing literature found that the current use of glycopeptides in pneumococcal infections is restricted to CNS infections facing therapeutic failure in due course. However, the belief that these drugs are the last resort, either in staphylococcal or enterococcal infections, is no longer valid. If a patient has a critical status due to probable gram-positive microorganisms, clinicians should consider the empiric use of glycopeptides. However, new molecules such as linezolid, QD, and daptomycin, offered for use in the treatment of gram-positive bacterial diseases, should be reserved for the future, when glycopeptides eventually become obsolete

Supraventricular Tachycardia with 2:1 Atrioventricular Block:

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73719/1/j.1540-8167.2000.tb00036.x.pd

Cost-Effectiveness of Radiofrequency Catheter Ablation for Atrial Fibrillation

ObjectivesWe sought to compare the cost-effectiveness of left atrial catheter ablation (LACA), amiodarone, and rate control therapy in the management of atrial fibrillation (AF).BackgroundLeft atrial catheter ablation has been performed to eliminate AF, but its cost-effectiveness is unknown.MethodsWe developed a decision-analytic model to evaluate the cost-effectiveness of LACA in 55- and 65-year-old cohorts with AF at moderate and low stroke risk. Costs, health utilities, and transition probabilities were derived from published literature and Medicare data. We performed primary threshold analyses to determine the minimum level of LACA efficacy and stroke risk reduction needed to make LACA cost-effective at $50,000 and$100,000 per quality-adjusted life-year (QALY) thresholds.ResultsIn 65-year-old subjects with AF at moderate stroke risk, relative reduction in stroke risk with an 80% LACA efficacy rate for sinus rhythm restoration would need to be ≥42% and ≥11% to yield incremental cost-effectiveness ratios (ICERs) <$50,000 and$100,000 per QALY, respectively. Higher and lower LACA efficacy rates would require correspondingly lower and higher stroke risk reduction for equivalent ICER thresholds. In the 55-year-old moderate stroke risk cohort, lower LACA efficacy rates or stroke risk reduction would be needed for the same ICER thresholds. In patients at low stroke risk, LACA was unlikely to be cost-effective.ConclusionsThe use of LACA may be cost-effective in patients with AF at moderate risk for stroke, but it is not cost-effective in low-risk patients. Our threshold analyses may provide a framework for the design of future clinical trials by providing effect size estimates for LACA efficacy needed

Conducting Randomized Trials in the Electrophysiology Laboratory: Lessons from a Randomized Comparison of Recording Methods During Pulmonary Vein Isolation by Segmental Ostial Ablation

Accurate identification of pulmonary vein (PV) potentials during segmental ostial ablation for PV isolation is very important to completely isolate the PVs and also to avoid unnecessary applications of radiofrequency energy. A prior post hoc analysis of unipolar and bipolar electrograms recorded from successful and unsuccessful ablation sites demonstrated that unipolar electrograms recorded at successful sites were more likely to have a rapid intrinsic deflection, larger amplitude, and earlier activation than electrograms recorded at unsuccessful sites. Moreover, unipolar electrograms recorded from the ablation and circular ostial mapping catheters were almost identical at successful sites. Based on these observations, a prospective, randomized study was conducted to test whether unipolar and bipolar electrograms would facilitate the ablation procedure when compared to bipolar electrograms alone during PV isolation in patients with atrial fibrillation (AF). In 44 consecutive patients with paroxysmal AF, 114 PVs were randomized to segmental ostial ablation guided by unipolar and bipolar electrograms (61) or by bipolar electrograms only (53). Segmental ostial ablation guided by unipolar and bipolar electrograms was associated with a ∼ 20–30% decrease in the procedure and fluoroscopy times necessary for isolation of a PV and also in the duration of radiofrequency energy application required for complete isolation of a PV. Although the sample size was not sufficient to detect a 5% change, the success rate for complete electrical isolation and the risk of symptomatic PV stenosis were similar between the 2 groups. Online analysis of unipolar electrograms facilitated the PV isolation procedure and was incremental to the analysis of bipolar electrograms alone. However, because segmental ostial ablation has only modest efficacy in achieving long-term freedom from recurrent AF, alternative ablation strategies that may or may not target PVs will eventually evolve. The role of unipolar electrograms in these new methods remains to be determined.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44683/1/10572_2004_Article_5253491.pd