Patient-specific characteristics determine success of surgical atrial fibrillation ablation in patients with persistent atrial fibrillation.

Surgical atrial fibrillation ablation (SAFA) has not achieved the efficacy of Cox's original maze procedure, although technical improvements continue to be made. It is possible that biologic factors determine SAFA success. Therefore we examined how patient-specific characteristics affected SAFA success in 353 atrial fibrillation (AF) patients who underwent SAFA at a single institution.

Physiological associations of computerized tomography lung density: a factor analysis.

Background: Objective quantification of emphysema using computerized tomography (CT) density measurements is rapidly gaining wide acceptance as an in vivo measurement tool. However, some studies have suggested that abnormal lung function in the absence of emphysema can affect lung density, and the role of such measurements in identifying and monitoring the progression of emphysema is not clear.

Objective: To clarify the relationship between lung density measurements and pulmonary function.

Effect of epicardial fat on ablation performance: a three-energy source comparison.

Objectives: To investigate the effect of epicardial fat on surgical atrial fibrillation ablation performance using an in vitro model. Two tissue models were employed to investigate standard penetration and maximal lesion depth performance of bipolar radiofrequency (RF), microwave, and laser energy sources.

Methods: Ventricular veal tissue was utilized in various thicknesses (3 mm, 5 mm, 7 mm, 15 mm).

Effects of cannabis on pulmonary structure, function and symptoms.

Background: Cannabis is the most widely used illegal drug worldwide. Long-term use of cannabis is known to cause chronic bronchitis and airflow obstruction, but the prevalence of macroscopic emphysema, the dose-response relationship and the dose equivalence of cannabis with tobacco has not been determined.

Methods: A convenience sample of adults from the Greater Wellington region was recruited into four smoking groups: cannabis only, tobacco only, combined cannabis and tobacco and non-smokers of either substance.

Pulmonary function testing in New Zealand: the use and importance of reference ranges.

Background And Objectives: The diagnosis, assessment and management of a wide range of respiratory diseases rely on accurate interpretation of lung function tests through the use of reference equations to generate predicted values. This paper ascertains the suitability of reference equations currently used in New Zealand through comparison with newly derived equations from the Wellington Respiratory Survey, and discusses the relevance of the findings to the Asia Pacific region.

Methods: A survey of lung function testing facilities determined the reference equations in common usage.

Reference ranges for exhaled nitric oxide derived from a random community survey of adults.

Rationale: Measurement of the fraction of nitric oxide in exhaled breath (Fe(NO)) has been proposed as a noninvasive marker of airway inflammation. Before the widespread use of this test, there is a need to develop reference ranges to allow clinicians to interpret Fe(NO) measurements.

Objectives: To derive reference ranges for Fe(NO) and to determine which factors in health and disease influence Fe(NO) levels.

An overview of energy sources in clinical use for the ablation of atrial fibrillation.

Recent years have seen many developments in the field of alternative energy sources for arrhythmia surgery. The impetus behind these advances is to replace the traditional, "cut-and-sew" Cox maze III procedure with lesion sets that are simpler, shorter, and safer but just as effective. There is demand for technology to make continuous, linear, transmural ablations reliably with a versatile energy source via an epicardial approach.

Utility of lung density measurements in the diagnosis of emphysema.

Background: The role of computerised tomography (CT) lung density measurements in objective quantification of emphysema is uncertain. The aim of this study was to determine normal reference values for CT lung density measurements and investigate their utility in identifying subjects with clinical emphysema.

Methods: Normal subjects (non-smokers, no respiratory disease, n=185) and subjects with clinical emphysema (post-bronchodilator FEV(1)/FVC <70%, > or =10 pack years tobacco smoking, no childhood asthma and, either D(LCO)/VA <80% predicted and/or macroscopic emphysema on CT, n=22) were identified from a random population survey.

Using random telephone sampling to recruit generalizable samples for family violence studies.

Convenience sampling methods predominate in recruiting for laboratory-based studies within clinical and family psychology. The authors used random digit dialing (RDD) to determine whether they could feasibly recruit generalizable samples for 2 studies (a parenting study and an intimate partner violence study). RDD screen response rate was 42-45%; demographics matched those in the 2000 U.

Agreement about acts of aggression in marriage.

Psychological and Physical Aggression scales met internal consistency and agreement standards on the Revised Conflict Tactics Scales (CTS2) in a randomly recruited sample of 453 married community couples with children. Moreover, partners agreed on the extent of psychological and physical aggression as much or more than they did on CTS2 Negotiation scale and positive behaviors assessed on the Dyadic Adjustment Scale. On the other hand, the CTS2 Sexual Coercion and Injury scales had much lower internal consistencies as measured by Cronbach's alpha, and agreement was generally very low.

Transcatheter aortic valve replacement in patients with critical aortic stenosis: rationale, device descriptions, early clinical experiences, and perspectives.

The development of lesser invasive transcatheter techniques for aortic valve replacement (AVR) to treat high surgical risk patients with severe aortic stenosis (AS) has engendered controversy among traditional cardiovascular therapists. Presently, there are two catheter-based treatment systems (the Cribier-Edwards Aortic Bioprosthesis and the CoreValve Revalving System) utilizing either a balloon-expandable or a self-expanding stent (or cage) platform which unfolds a pericardial tissue valve within the displaced diseased aortic valve. After ex vivo durability testing and animal studies, several clinical registries with these transcatheter AVR systems in almost 300 patients worldwide have demonstrated the following: (1) good acute hemodynamic performance with reduction in mean aortic valve gradients to <10 mm Hg; (2) frequent para-valvular regurgitation, which has improved with self-expanding devices and the use of larger (26 mm) valve sizes; (3) acceptable periprocedural (30-day) mortality (<10%) with the newest generation devices and improved operator techniques.

External validity of randomized controlled trials in COPD.

Background: COPD is a heterogeneous disease comprising a wide range of clinical phenotypes, depending on the degree to which emphysema, chronic bronchitis, reversible bronchospasm and small airways inflammation are present. Not all of these phenotypes may be represented among the subjects included in randomized controlled drug trials (RCTs) in COPD, making it difficult for doctors to know to what extent RCT evidence applies to individual patients. From a respiratory health survey of adults randomly selected from the community, we have estimated the proportion of subjects with COPD who would have been eligible for inclusion in major COPD RCTs.

External validity of randomised controlled trials in asthma: to whom do the results of the trials apply?

Background: Asthma is a heterogeneous disease with a wide range of clinical phenotypes, not all of which may be encompassed in the subjects included in randomised controlled trials (RCTs). This makes it difficult for clinicians to know to what extent the evidence derived from RCTs applies to a given patient.

Aim: To calculate the proportion of individuals with asthma who would have been eligible for the major asthma RCTs from the data of a random community survey of respiratory health.

Off-pump epicardial atrial fibrillation surgery utilizing a novel bipolar radiofrequency system.

Background: Over the past several years, pulmonary vein isolation for the treatment of atrial fibrillation has gained significant popularity. This study was undertaken to evaluate a novel radiofrequency (RF)-enabled clamp system designed to create transmural lesions epicardially on the beating heart using bipolar RF.

Methods: A set of differently shaped clamps modified to deliver bipolar RF energy were used to create a series of lesions in a beating heart canine model.

Evidence from Amazonian forests is consistent with isohydric control of leaf water potential.

Climate modelling studies predict that the rain forests of the Eastern Amazon basin are likely to experience reductions in rainfall of up to 50% over the next 50-100 years. Efforts to predict the effects of changing climate, especially drought stress, on forest gas exchange are currently limited by uncertainty about the mechanism that controls stomatal closure in response to low soil moisture. At a through-fall exclusion experiment in Eastern Amazonia where water was experimentally excluded from the soil, we tested the hypothesis that plants are isohydric, that is, when water is scarce, the stomata act to prevent leaf water potential from dropping below a critical threshold level.

Complete reference ranges for pulmonary function tests from a single New Zealand population.

Aim: Reference equations are prerequisites for interpretation of pulmonary function tests and are important in diagnosis, assessment, and management of a range of respiratory conditions. Such equations should be derived from populations who are closely ethnically and anthropomorphically matched to those in whom the equations will be used. This paper uses measurements from a single cohort of New Zealand adults to derive reference equations for all major pulmonary function tests.

Surgical ablation of atrial fibrillation: the Columbia Presbyterian experience.

Background: The Maze III procedure is an effective surgical treatment for atrial fibrillation (AF). However, it is not widely applied due to its complexity, increased operative times, and the risk of bleeding. Various energy sources have been introduced to simplify the traditional "cut and sew" approach.

Duration of action of the salmeterol/fluticasone combination inhaler administered in the evening: a randomized controlled trial in childhood asthma.

Objective And Background: To investigate the duration of bronchodilator action of a salmeterol/fluticasone combination (SFC) inhaler when administered in the evening to children with asthma.

Design: A double-blind, placebo-controlled, cross-over study.

Setting: Hospital inpatient.

Radiofrequency and microwave energy sources in surgical ablation of atrial fibrillation: a comparative analysis.

Background: Due to its complexity and risk of bleeding, the Maze III procedure has been largely replaced by surgical ablation for atrial fibrillation (AF) using alternative energy sources. Radiofrequency (RF) and microwave (MW) are the most commonly used energy forms. In this study, we sought to compare these energy modalities in terms of clinical outcomes.

Mechanisms of atrial tachyarrhythmias following surgical atrial fibrillation ablation.

Introduction: Typical and atypical atrial flutters (AFLs) and atrial tachycardias (ATs) have been reported in patients with prior surgical atrial fibrillation ablation. The underlying mechanisms for this group of atrial tachyarrhythmias have not been well characterized and the efficacy of catheter ablation in their treatment is unknown.

Methods And Results: Twenty patients (6 females) with a surface ECG diagnosis of AFL or AT following surgical atrial fibrillation ablation underwent 26 electrophysiology studies.

Epicardial cardiac ablation using laser energy.

We describe epicardial ablation using a new device that utilizes 980 nm wavelength laser energy. The device can be used in both open and minimally invasive approaches and should make ablation therapy safe, effective, and easy to use.

The 24 h duration of bronchodilator action of the budesonide/formoterol combination inhaler.

Introduction: The duration of bronchodilator action of the long-acting beta-agonist formoterol when administered in the evening has not been investigated. In this study we have investigated whether a single evening dose of formoterol, administered from the combination budesonide/formoterol (BUD/F) Turbuhaler significantly attenuates the circadian rhythm in airway tone over 24 h.

Methods: Twenty subjects with mild to moderate asthma (mean FEV1 84% predicted) participated in a double-blind, placebo-controlled, cross-over study.

The 24 h duration of bronchodilator action of the salmeterol/fluticasone combination inhaler.

Introduction: The duration of bronchodilator action of the long-acting beta agonist salmeterol when administered in the evening has not been investigated. In this study we have investigated whether a single evening dose of salmeterol, administered from the combination salmeterol/fluticasone (SFC) Accuhaler significantly attenuates the circadian rhythm in airway tone over 24 h.

Methods: Eighteen subjects with mild to moderate asthma (mean FEV1 84% predicted) participated in a double-blind, double dummy, placebo controlled, cross-over study.

Tight coupling between leaf area index and foliage N content in arctic plant communities.

The large spatial heterogeneity of arctic landscapes complicates efforts to quantify key processes of these ecosystems, for example productivity, at the landscape level. Robust relationships that help to simplify and explain observed patterns, are thus powerful tools for understanding and predicting vegetation distribution and dynamics. Here we present the same linear relationship between Leaf area index (LAI) and Total foliar nitrogen (TFN), the two factors determining the photosynthetic capacity of vegetation, across a wide range of tundra vegetation types in both northern Sweden and Alaska between leaf area indices of 0 and 1 m2 m(-2), which is essentially the entire range of leaf area index values for the Arctic as a whole.

Minimally invasive surgery for atrial fibrillation: toward a totally endoscopic, beating heart approach.

In the last several years, a number of procedures have been conceived that have attempted to treat atrial fibrillation (AF) by creating a limited set of lesions modeled after those of the Maze operation. These lesions have been created by a variety of means, including the traditional cut-and-sew method, but also by nonincisional techniques. These have included cryoablation as well as several thermal techniques, using radiofrequency, microwave, laser, and focused ultrasound energy.