Structural and electro-anatomical characterization of the equine pulmonary veins: implications for atrial fibrillation.

INTRODUCTION/OBJECTIVES: Spontaneous pulmonary vein (PV) activity triggers atrial fibrillation (AF) in humans. Although AF frequently occurs in horses, the origin remains unknown. This study investigated the structural and electro-anatomical properties of equine PVs to determine the potential presence of an arrhythmogenic substrate. ANIMALS, MATERIALS AND METHODS: Endocardial three-dimensional electro-anatomical mapping (EnSite Precision) using high-density (HD) catheters was performed in 13 sedated horses in sinus rhythm. Left atrium (LA) access was obtained retrogradely through the carotid artery. Post-mortem, tissue was harvested from the LA, right atrium (RA), and PVs for histological characterization and quantification of ion channel expression using immunohistochemical analysis. RESULTS: Geometry, activation maps, and voltage maps of the PVs were created and a median of four ostia were identified. Areas of reduced conduction were found at the veno-atrial junction. The mean myocardial sleeve length varied from 28 ± 13 to 49 ± 22 mm. The PV voltage was 1.2 ± 1.4 mV and lower than the LA (3.4 ± 0.9 mV, P < 0.001). The fibrosis percentage was higher in PV myocardium (26.1 ± 6.6%) than LA (14.5 ± 5.0%, P = 0.003). L-type calcium channel (CaV1.2) expression was higher in PVs than LA (P = 0.001). T-type calcium channels (CaV3.3), connexin-43, ryanodine receptor-2, and small conductance calcium-activated potassium channel-3 was expressed in PVs. CONCLUSIONS: The veno-atrial junction had lower voltages, increased structural heterogeneity and areas of slower conduction. Myocardial sleeves had variable lengths, and a different ion channel expression compared to the atria. Heterogeneous properties of the PVs interacting with the adjacent LA likely provide the milieu for re-entry and AF initiation.

Tissue characterization of acute lesions during cardiac magnetic resonance-guided ablation of cavo-tricuspid isthmus-dependent atrial flutter: a feasibility study.

AIMS: To characterize acute lesions during cardiac magnetic resonance (CMR)-guided radiofrequency (RF) ablation of cavo-tricuspid isthmus (CTI)-dependent atrial flutter by combining T2-weighted imaging (T2WI), T1 mapping, first-pass perfusion, and late gadolinium enhancement (LGE) imaging. CMR-guided catheter ablation offers a unique opportunity to investigate acute ablation lesions. Until present, studies only used T2WI and LGE CMR to assess acute lesions. METHODS AND RESULTS: Fifteen patients with CTI-dependent atrial flutter scheduled for CMR-guided RF ablation were prospectively enrolled. Directly after achieving bidirectional block of the CTI line, CMR imaging was performed using: T2WI (n = 15), T1 mapping (n = 10), first-pass perfusion (n = 12), and LGE (n = 12) imaging. In case of acute reconnection, additional RF ablation was performed. In all patients, T2WI demonstrated oedema in the ablation region. Right atrial T1 mapping was feasible and could be analysed with a high inter-observer agreement (r = 0.931, ICC 0.921). The increase in T1 values post-ablation was significantly lower in regions showing acute reconnection compared with regions without reconnection [37 ± 90 ms vs. 115 ± 69 ms (P = 0.014), and 3.9 ± 9.0% vs. 11.1 ± 6.8% (P = 0.022)]. Perfusion defects were present in 12/12 patients. The LGE images demonstrated hyper-enhancement with a central area of hypo-enhancement in 12/12 patients. CONCLUSION: Tissue characterization of acute lesions during CMR-guided CTI-dependent atrial flutter ablation demonstrates oedema, perfusion defects, and necrosis with a core of microvascular damage. Right atrial T1 mapping is feasible, and may identify regions of acute reconnection that require additional RF ablation.

A single-centre prospective evaluation of left bundle branch area pacemaker implantation characteristics.

BACKGROUND: Left bundle branch area pacing (LBBAP) has recently been introduced as a physiological pacing technique with synchronous left ventricular activation. It was our aim to evaluate the feasibility and learning curve of the technique, as well as the electrical characteristics of LBBAP. METHODS AND RESULTS: LBBAP was attempted in 80 consecutive patients and electrocardiographic characteristics were evaluated during intrinsic rhythm, right ventricular septum pacing (RVSP) and LBBAP. Permanent lead implantation was successful in 77 of 80 patients (96%). LBBAP lead implantation time and fluoroscopy time shortened significantly from 33 ± 16 and 21 ± 13 min to 17 ± 5 and 12 ± 7 min, respectively, from the first 20 to the last 20 patients. Left bundle branch (LBB) capture was achieved in 54 of 80 patients (68%). In 36 of 45 patients (80%) with intact atrioventricular conduction and narrow QRS, an LBB potential (LBBpot) was present with an LBBpot to onset of QRS interval of 22 ± 6 ms. QRS duration increased significantly more during RVSP (141 ± 20 ms) than during LBBAP (125 ± 19 ms), compared to 130 ± 30 ms without pacing. An even clearer difference was observed for QRS area, which increased significantly more during RVSP (from 32 ± 16 µVs to 73 ± 20 µVs) than during LBBAP (41 ± 15 µVs). QRS area was significantly smaller in patients with LBB capture compared to patients without LBB capture (43 ± 18 µVs vs 54 ± 21 µVs, respectively). In patients with LBB capture (n = 54), the interval from the pacing stimulus to R­wave peak time in lead V6 was significantly shorter than in patients without LBB capture (75 ± 14 vs 88 ± 9 ms, respectively). CONCLUSION: LBBAP is a safe and feasible technique, with a clear learning curve that seems to flatten after 40-60 implantations. LBB capture is achieved in two-thirds of patients. Compared to RVSP, LBBAP largely maintains ventricular electrical synchrony at a level close to intrinsic (narrow QRS) rhythm.

Clinical determinants of early spontaneous conversion to sinus rhythm in patients with atrial fibrillation.

BACKGROUND: The current standard of care for acute atrial fibrillation (AF) focuses primarily on immediate restoration of sinus rhythm by cardioversion, although AF often terminates spontaneously. OBJECTIVE: To identify determinants of early spontaneous conversion (SCV) in patients presenting at the emergency department (ED) because of AF. METHODS: An observational study was performed of patients who visited the ED with documented AF between July 2014 and December 2016. The clinical characteristics and demographics of patients with and without SCV were compared. RESULTS: We enrolled 943 patients (age 69 ± 12 years, 47% female). SCV occurred within 3 h of presentation in 158 patients (16.8%). Logistic regression analysis showed that duration of AF <24 h [odds ratio (OR) 7.7, 95% confidence interval (CI) 3.5-17.2, p < 0.001], left atrial volume index <42 ml/m2 (OR 1.8, 95% CI 1.2-2.8, p = 0.010), symptoms of near-collapse at presentation (OR 2.4, 95% CI 1.2-5.1, p = 0.018), a lower body mass index (BMI) (OR 0.9, 95% CI 0.91-0.99, p = 0.028), a longer QTc time during AF (OR 1.01, 95% CI 1.0-1.02, p = 0.002) and first-detected AF (OR 2.5, 95% CI 1.6-3.9, p < 0.001) were independent determinants of early SCV. CONCLUSION: Early spontaneous conversion of acute AF occurs in almost one-sixth of admitted patients during a short initial observation in the ED. Spontaneous conversion is most likely to occur in patients with first-onset, short-duration AF episodes, lower BMI, and normal left atrial size.

Low resting heart rates are associated with new-onset atrial fibrillation in patients with vascular disease: results of the ONTARGET/TRANSCEND studies.

BACKGROUND: Elevated systolic blood pressure (SBP) and high resting heart rate (HR) are associated with cardiovascular end-points. Although the association between atrial fibrillation (AF) and SBP is well established, the relation between AF and HR remains unclear. METHODS: In patients from the ONTARGET and TRANSCEND studies with high cardiovascular disease risk (n = 27 064), new-onset AF was evaluated in relation to mean SBP, visit-to-visit variation in SBP (SBP-CV; i.e. SD/mean × 100%), mean HR and visit-to-visit variation in HR (HR-CV). RESULTS: Low mean HR (P < 0.0001) and high SBP (P = 0.0021) were associated with incident AF. High SBP-CV (P = 0.031) and HR-CV (P < 0.0001) were also associated with incident AF. After adjustment for confounders, SBP and SBP-CV were no longer significantly associated with AF. The detrimental effect of low HR was particularly evident in subjects who were not receiving treatment with beta-blockers (P = 0.014 for interaction between beta-blocker use and mean HR). In addition to low HR, high HR-CV and high SBP had additive effects on incident AF. CONCLUSIONS: Low mean HR (<60 beats min(-1) ) is independently associated with incident AF, and low HR-CV and high SBP further increase the incidence of new-onset AF in patients at high risk of cardiovascular disease.

Resting heart rate is associated with renal disease outcomes in patients with vascular disease: results of the ONTARGET and TRANSCEND studies.

BACKGROUND: Resting heart rate (RHR) is associated with cardiovascular disease outcomes in high-risk patients. It is not known whether RHR is predictive of renal outcomes such as albuminuria, end-stage renal disease (ESRD) or doubling of creatinine. We evaluated whether RHR could predict renal endpoints in patients at a high risk of cardiovascular disease. We also tested the effects of RHR at different levels of systolic blood pressure (SBP). METHODS: We analysed data from 28 757 patients in the ONTARGET and TRANSCEND trials. RHR and SBP were available for a mean of 4.9 ± 0.4 visits (range 3-5) within the first 2 years of the studies. Albuminuria was determined at baseline, at 2 years and at study end. RESULTS: Mean RHR was predictive of incident micro-albuminuria [hazard ratio (HR) for RHR ≥80 vs. <60 beats min(-1) 1.49, 95% confidence interval (CI) 1.29-1.71, P < 0.0001], incident macro-albuminuria (HR 1.84, 95% CI 1.39-2.42, P < 0.0001), doubling of creatinine (HR 1.47, 95% CI 1.00-2.17, P = 0.050) and ESRD (HR 1.78, 95% CI 1.00-3.16, P = 0.050), and the combined renal end-point (HR 1.51, 95% CI 1.32-1.74, P < 0.0001). Associations were robust at SBPs from <120 to ≥150 mmHg, with the lowest risk at a SBP of 130-140 mmHg. CONCLUSION: Resting heart rate is a potent predictor of these renal outcomes, as well as their combination, in patients with cardiovascular disease. RHR at all SBP levels should be considered as a possible renal disease risk predictor and should be investigated as a treatment target with RHR-reducing agents.

[Interventional hypertension therapy in diabetes mellitus. Effects on blood pressure and glucose metabolism?]. / Interventionelle Hypertonietherapie bei Diabetes mellitus. Effekte auf Blutdruck und Glukosestoffwechsel?

Hypertension is the most common chronic cardiovascular disease with increasing prevalence all over the world. Despite the availability of many effective antihypertensive drugs, blood pressure control to target values remains low. In the pathophysiology of therapy resistant hypertension, increased activity of the sympathetic nervous system with an imbalance between sympathetic and parasympathetic activity has been identified as a main contributor to the development and maintenance of hypertension. Catheter-based denervation of the renal sympathetic nerves has been described as reducing blood pressure and decreasing sympathetic activity in patients with resistant hypertension. Supplementary beneficial effects on common cardiovascular comorbidities, such as diabetes type 2, have been reported. The present review aims to give an overview about percutaneous renal denervation for treatment of hypertension and potential new therapeutic options to improve glycemic control.

Changes in arterial function in a mouse model of human familial hypercholesterolaemia.

AIM: Atherosclerosis is the most common cause of cardiovascular disease. The ApoB mouse is a model for human familial hypercholesterolaemia and has a lipoprotein profile similar to that of humans with atherosclerosis. Therefore, it is a suitable model to investigate the changes in vasoreactivity during atherogenesis. This study investigates contractile and dilatative properties of arteries in this model in relation to age. METHODS: Male ApoB mice and B6, wild-type (WT), mice were examined at age four or 18 months. Isometric measurements of 2-mm ring preparations of the aorta thoracica were performed using a wire myograph. Histological and biochemical methods served to determine atherosclerosis, lipid status and endothelial markers respectively. RESULTS: Morphometric analysis showed that all old ApoB mice had severe atherosclerosis in the aorta. Atherosclerotic alteration of the aorta of the ApoB mice coincided with a diminished vasodilatation to acetylcholine. The phenylephrine response was significantly attenuated already to the same degree in the non-atherosclerotic aorta of the young ApoB mice as in the atherosclerotic aorta of the older ApoB mice. Serum parameters showed a rise in total cholesterol and triglycerides in the ApoB strain compared to WT mice. Soluble intercellular adhesion molecule (sICAM)-1 and soluble vascular adhesion molecule (sVCAM)-1 were increased in old compared to young ApoB mice. CONCLUSION: The study shows that reduced acetylcholine-induced dilatation is related to the presence of atherosclerosis in old ApoB mice. Remarkably, the impaired vessel reactivity to phenylephrine already in young ApoB mice indicates early changes in vascular function in this model.

[Heart and kidneys. Renal denervation as therapy for hypertension]. / Herz und Niere. Hochdrucktherapie durch renale Denervation.

Arterial hypertension is a major cardiovascular risk factor with a high prevalence in western industrial countries and the proportion of patients with blood pressure at target values remains low. Patients with therapy-resistant hypertension, defined as failure to achieve target blood pressure despite a triple antihypertensive drug regimen including a diuretic, are at very high risk which supports the need for greater efforts towards improving hypertension outcomes in this population. Secondary causes of hypertension are often found in patients with resistant hypertension. Activation of the sympathetic nervous system has been identified as a main contributor to the development and progression of high blood pressure. Catheter-based renal denervation offers a new interventional treatment option resulting in a significant long-term reduction in blood pressure (> 36 months) and increased blood pressure control (up to 40% of the treated population). The basis for successful treatment is an appropriate patient selection, including life-style modification, exclusion of pseudoresistance, termination of substances increasing blood pressure and an optimized drug treatment. Further clinical studies are warranted and ongoing to determine the role of renal denervation in antihypertensive treatment.

Care management of work injuries: results of a 1-year pilot outcome assurance program.

A 1-year pilot study was conducted, linking the efforts of a workers' compensation managed care organization with those of an occupational health clinic and emergency department of manage work-related injuries and associated work disability. Sustained (> 90 day), injury-specific return-to-work outcomes, modified by job title, were compared with loosely managed and well-managed benchmarks. The mean return-to-work outcome, measured as lost workdays (LWDs), was 5.11 +/- 21.0 LWDs for 418 workers. These results exceeded benchmarks for both loosely managed care, 14.0 +/- 17.2 LWDs, P < 0.001 (8.9 fewer LWDs/case), and optimally case-managed care, 6.99 +/- 7.64 LWDs, P = 0.044 (1.9 fewer LWDs/case). An estimate of the value of these saved LWDs to the employers-at $200 per workday was $740,400 for the loosely managed benchmarks and $157,000 for the well-managed benchmarks. The Outcome Assurance Program virtually eliminated typical delays in the diagnosis and medical management of these injured workers.

Testing legal assumptions regarding the effects of dancer nudity and proximity to patron on erotic expression.

A field experiment was conducted in order to test the assumptions by the Supreme Court in Barnes v. Glen Theatre, Inc. (1991) and the Ninth Circuit Court of Appeals in Colacurcio v. City of Kent (1999) that government restrictions on dancer nudity and dancer-patron proximity do not affect the content of messages conveyed by erotic dancers. A field experiment was conducted in which dancer nudity (nude vs. partial clothing) and dancer-patron proximity (4 feet; 6 in.; 6 in. plus touch) were manipulated under controlled conditions in an adult night club. After male patrons viewed the dances, they completed questionnaires assessing affective states and reception of erotic, relational intimacy, and social messages. Contrary to the assumptions of the courts, the results showed that the content of messages conveyed by the dancers was significantly altered by restrictions placed on dancer nudity and dancer-patron proximity. These findings are interpreted in terms of social psychological responses to nudity and communication theories of nonverbal behavior. The legal implications of rejecting the assumptions made by the courts in light of the findings of this study are discussed. Finally, suggestions are made for future research.

Disability case management: an impact assessment in an automotive manufacturing organization.

A multifaceted disability management program was instituted at an automotive manufacturing organization to control rising workers' compensation costs. A pilot program showed major cost savings over a 9-month period. When total and component disability leave rates were calculated as a percentage of the available workforce and tracked on a weekly basis over the subsequent 3 years, total disability leave rates fell by nearly 50%. This was largely attributable to an approximately 50% decrease in the extended (> 1-year) disability leave rate and a 75% decrease in the workers' compensation leave rate. A novel approach to biostatistical analysis showed a good fit of weekly disability leave rates to a Poisson random variable distribution with an identifiable break point at about 1 1/2 years after observation for extended disability leaves and at 2 years for workers' compensation leaves. This biostatistical approach may prove generalizable to tracking leave rates in other organizations.

Cluster analysis applied to building-related illness.

Identifying remediable causes of occupant symptoms in building-related illness is frequently difficult. This is particularly true when the building-wide prevalence of symptoms is comparable to that reported in non-problem buildings. This analysis applied an epidemiological approach to an assessment of a problem building, allowing investigators to visually identify an area of apparent increased symptom density. A cluster analysis approach permitted biostatistical confirmation of the visual cluster. Building-related symptom reporting was statistically significantly associated with a prior physician diagnosis of dust and/or mold allergy. The likely etiology of building occupant symptoms was identified within the region implicated by the cluster analysis. This approach may be useful to focus building evaluations on both the likely physical source and general characteristics of suspect etiologic agents.

Women's reactions to sexually aggressive mass media depictions.

PIP: This study examines the potential harm of sexually explicit and/or violent films to women viewers. More specifically, it investigates the idea that the visual media contribute to a cultural climate that is supportive of attitudes facilitating violence against women, diminish concern for female victims (desensitization), and have a negative impact on women's views of themselves. In this study, women viewed 1 film per day for 4 consecutive days from one of these 3 categories: 1) sexually explicit but nonviolent; 2) sexually explicit, sexually violent; and 3) mildly sexually explicit, graphically violent. They then served as jurors in a simulated rape trial. The study found that exposure to both types of violent stimuli produced desensitization and ratings of the stimuli as less degrading to women. Moreover, women exposed to the mildly sexually explicit, graphically violent images were less sensitive toward the victim in the rape trial compared with the other film viewers. However, no differences were found between the film groups and the no-exposure control group with regard to women¿s self-perception.^ieng

Postural stability assessment in sewer workers.

In this study, postural stability was measured with a microcomputer-based force platform as an indirect assessment of central nervous system effect in 28 sewer workers (age range 23.4 to 64.5 years, standard deviation of 8.7 years). All workers performed four 30-second postural sway tests. The organic-solvent exposure was measured by a photo-ionization detector. The photo-ionization detector was calibrated to measure volatile organic solvents in total benzene equivalence, and concentrations were measured in various parts of the plant. The mean exposure was .32 parts per million (ppm) benzene equivalent (range of .02 to .95 ppm, standard deviation .19 ppm). Based on a covariate adjusted linear multiple-regression model, a statistically significant (p < .05) positive correlation was demonstrated between postural sway and organic-solvent exposure. These workers also had increased postural sway compared with a nonexposed population. The statistically significant correlation between postural sway determinations and organic-solvent exposure was surprising given the very low exposures measured. It is possible that the organic-solvent exposure might not be the causative agent, but rather that the solvents themselves correlate with some other causative exposure, ie, total volatile organics as implicated in the cause of sick-building syndrome.

Repair of mucosal perforation during pyloromyotomy: surgeon's choice.

Mucosal perforation during Fredet-Ramstedt pyloromyotomy traditionally has been repaired with muscular and mucosal reapproximation, pyloric rotation, and repeat myotomy. The purpose of this study was to determine whether simple mucosal closure is a safe alternative repair technique for such a perforation. The authors reviewed their experience of pyloromyotomies over a 21-year period and found a 1.67% incidence (15 of 896) of mucosal perforation. Four of these patients had repair with rotation and repeat myotomy, and 11 had repair with primary mucosal approximation. The patients were compared with respect to demographics, duration of operation, postoperative feeding intolerance, time from operation until discharge, and postoperative complications. No differences were noted between the two groups. Interestingly, when the perforation group (n = 15) was compared with the nonperforation group (n = 881), the mean age at time of pyloromyotomy was significantly higher for the group with perforation 48 days v 34 days; P = .0021, Student's t test). The authors conclude that those most likely to suffer mucosal perforation during pyloromyotomy are older patients with pyloric stenosis. Such mucosal perforation can be repaired with equal efficacy and safety using the traditional pyloric rotation approach or primary mucosal closure.

Desensitization and resensitization to violence against women: effects of exposure to sexually violent films on judgments of domestic violence victims.

An experiment was conducted to examine the effects of repeated exposure to sexually violent films on emotional desensitization and callousness toward domestic abuse victims. Results indicated that emotional response, self-reported physiological arousal, and ratings of the extent to which the films were sexually violent all diminished with repeated film exposure. Three days following exposure to the final film, experimental participants expressed significantly less sympathy for domestic violence victims, and rated their injuries as less severe, than did a no-exposure comparison group. Five days after the final film exposure, their level of sensitivity to the domestic violence victims had rebounded to baseline levels established by the comparison group. Emotional responsiveness at the final film exposure was correlated with levels of sensitivity to the domestic violence victims 3 days later but not at subsequent observation points.

Using the confluence model of sexual aggression to predict men's conflict with women: a 10-year follow-up study.

We tested a model describing the characteristics of sexually aggressive men that may also be useful for understanding the causes of other antisocial acts against women. This model hypothesizes that sexual aggressors can be identified by two sets of characteristics, labeled hostile masculinity and impersonal sex. To test this model, we followed up a sample of men 10 years after first studying them when they were young adults. We sought to predict which men would be in distressed relationships with women, be aggressive sexually, be nonsexually aggressive, or some combination of these. These behaviors were measured not only by questioning the men themselves but also by questioning many of the men's female partners. Some couples' videotaped conversations were also analyzed. The data supported the ability of the model to predict behavior 10 years later. We also developed the model further and identified the common and unique characteristics contributing to sexual aggression as compared with the other conflictual behaviors studied. The data supported the usefulness of hierarchical modeling incorporating both general factors that contribute to various interpersonal conflicts as well as specific factors uniquely pertaining to dominance of women.