Microbial contamination and the sterilization/disinfection of surgical guides used in the placement of endosteal implants.

PURPOSE: The purpose of this study was twofold: (1) to estimate the level of microbial contamination found on commercial guides (CG) and in-house laboratory guides (LG) prior to use, and (2) to evaluate the antimicrobial potential of disinfectants commonly used in dentistry to decontaminate heat-sensitive surgical guides. Ethylene oxide gas was used as the positive control; sterile water served as a negative control. MATERIALS AND METHODS: Evaluation of CGs and LGs for bacterial contamination occurred soon after their arrival in the laboratory. Some guides went directly into tubes of trypticase soy broth solution, vortexed and equally divided into two tubes. One tube went into an 80°C bath for 19 minutes, while the other stayed at room temperature. After plating, half of the samples underwent anaerobic incubation. All incubation was for 48 hours at 37°C. Other guides underwent water rinsing or disinfection by various methods for 5 or 15 minutes or ethylene oxide gas sterilization prior to sampling. RESULTS: Untreated CG specimens showed modest levels of bacterial contamination, with most colonies coming from liquid specimens not exposed to 80°C. LG specimens had more bacteria from both heat-treated and non-heat-treated aliquots. Chlorhexidine gluconate, diluted bleach, and water rinsing were not able to completely eliminate microorganisms on the specimens, but no viable microorganisms were present on specimens treated with gas sterilization or 70% ethanol for 15 minutes. CONCLUSION: CGs and LGs, on average, had different levels of bacterial contamination prior to disinfection. Water, chlorhexidine gluconate, and diluted bleach were not totally successful in decontaminating the surgical guides, but no growth was found after 15 minutes of immersion in 70% ethanol. Preferably, surgical guides should be submerged in 70% alcohol for a minimum of 15 minutes or undergo sterilization using ethylene oxide gas.

Atrial flutter versus atrial fibrillation in a general population: differences in comorbidities associated with their respective onset.

OBJECTIVE: Determine and compare the prevalence of known risk factors for cardiovascular disease among unselected individuals presenting with their first ever episode of atrial flutter (AFL) and atrial fibrillation (AF). STUDY DESIGN AND SETTING: We evaluated 11 pre-selected clinical variables including age, sex, smoking history and other potential cardiac risk factors. Using the resources of the Marshfield Epidemiologic Study Area, a population-based database, all newly diagnosed cases of either AFL or AF in the region during a 4-year period were identified. RESULTS: Among the 472 incident cases, 76 (16.1%) had AFL and 396 (83.9%) had AF. Compared to those with AF, subjects with AFL were more likely to have had a history of chronic obstructive pulmonary disease (25% vs. 12%, P = 0.006), heart failure (28% vs. 17%, P = 0.05), and smoking (49% vs. 37%, P = 0.06). Hypertension, on the other hand, was more common among individuals with AF (63% vs. 47%, P = 0.01). CONCLUSION: This study represents the first report to evaluate potential differences in the conditions associated with the development of AFL versus AF. Research into the mechanisms of atrial arrhythmogenesis may lead to improved preventive and therapeutic interventions.

Prevalence and mortality of patients with myocardial infarction and reduced left ventricular ejection fraction in a defined community: relation to the second multicenter automatic defibrillator implantation trial.

OBJECTIVES: We compared characteristics and mortality of patients from a community population meeting enrollment criteria of the second Multicenter Automatic Defibrillator Implantation Trial (MADIT II) to those of the MADIT II subjects. BACKGROUND: MADIT II showed that implantable cardioverter-defibrillators (ICDs) reduce mortality in patients with myocardial infarction (MI) and low left ventricular ejection fraction (LVEF)

Familial atrioventricular nodal reentry tachycardia.

Dual atrioventricular nodal pathways, the substrate responsible for atrioventricular node reentry tachycardia (AVNRT), are thought to be randomly occurring congenital anomalies. This article describes 14 patients in six families, each with two or three first-degree relatives with paroxysmal supraventricular tachycardia. Electrophysiological evidence of dual atrioventricular nodal pathways was established in all 13 patients studied, AVNRT was induced in 12 (92%), and radiofrequency ablation of the slow pathway was curative in all cases. The data suggest a hereditary contribution to the development of atrioventricular nodal pathways and AVNRT. The pattern of inheritance appears to be autosomal dominant.

A population-based study of mortality among patients with atrial fibrillation or flutter.

PURPOSE: To determine the mortality associated with atrial flutter and atrial fibrillation in the general population. SUBJECTS AND METHODS: Using the Marshfield Epidemiologic Study Area, a database that captures nearly all medical care and deaths among its 58,820 residents, we identified patients diagnosed with atrial flutter or atrial fibrillation from July 1, 1991, through June 30, 1995. Patients were followed prospectively and compared with a group of controls without these arrhythmias. RESULTS: A total of 4775 person-years of follow-up were completed in 577 patients and 577 controls. Compared with controls, mortality among patients with atrial fibrillation or flutter was nearly 7.8-fold higher at 6 months (95% confidence interval [CI]: 4.1 to 15) and 2.5-fold higher (95% CI: 2.0 to 3.1; P < 0.0001) at the last follow-up (mean [+/- SD] of 3.6 +/- 2.3 years; range, 1 day to 7.3 years). At 6 months, mortality among patients with atrial flutter alone was somewhat greater than in controls and less than one third that of those with atrial fibrillation (with or without atrial flutter) (P = 0.02). At the last follow-up, however, mortality was greater among patients with atrial flutter (hazard ratio [HR] = 1.7; 95% CI: 1.2 to 2.6; P = 0.007), atrial fibrillation (HR = 2.4; 95% CI: 1.9 to 3.1; P < 0.0001), or both atrial arrhythmias (HR = 2.5; 95% CI: 1.9 to 3.3; P < 0.0001) when compared with controls in models that adjusted for cardiovascular risk factors. CONCLUSION: In the general population, both atrial flutter and atrial fibrillation are independent predictors of increased late mortality. The relatively benign course during the 6-month period after the initial diagnosis of atrial flutter suggests that early diagnosis and treatment of these patients may improve their long-term survival.