Ventricular rate stabilization for the prevention of pause dependent ventricular tachyarrhythmias: results from a prospective study in 309 ICD recipients

Reviews of stored electrograms from ICDs revealed a 5-30% incidence of short-long-short intervals preceding the onset of recurrent ventricular tachyarrhythmias. Rate stabilization by dedicated antibradycardia pacing algorithms has, therefore, been suggested to prevent onset of pause dependent tachyarrhythmias. However, the clinical efficacy of this approach has not been studied systematically. In a prospective multicenter crossover study, patients were randomized to activation or deactivation of an implemented ventricular rate stabilization algorithm (VRS) after first implant of a dual chamber ICD. After 3 months, all patients were crossed over to the alternate programming. The rate of appropriate spontaneous VA episodes was compared between VRS On and VRS Off. Stored electrograms were reviewed for evaluation of the mode of onset of tachyarrhythmias. Overall efficacy analysis was based on 309 patients enrolled in the study. Forty percent (124/309) of the patients experienced 4,973 VA episodes. Based on an intention-to-treat analysis, VRS Off and On arrhythmia incidence was 10.2 and 6.6 normalized to 3 months, respectively (risk reduction 35%; P = 0.18) On an on-treatment basis, a reduction from 9.0 episodes to 8.1 episodes (10% risk reduction, P = 0.24) was seen. In an extended Cox model adjusting for confounding variables, the relative risk for recurrent episodes was 0.92 during VRS On compared to Off (95% CI: 0.58-1.48; P = 0.74). During VRS Off, pause dependent onset was documented in only 36 (8%) of 427 visually analyzed episodes. There was no significant reduction in the incidence of recurrent ventricular tachyarrhythmias with VRS On compared to the Off programming in this prospective study.     

Association between extent of axillary lymph node dissection and patient,tumor, surgeon,and hospital factors in patients with early breast cancer

BACKGROUND AND OBJECTIVES: Axillary lymph node dissection (ALND) in patients with breast cancer is crucial for accurate staging, provides excellent regional tumor control, and is included in the standard of care for the surgical treatment of breast cancer. However, the extent of ALND varies, and the extent of dissection and the number of lymph nodes that comprise an optimal axillary dissection are under debate. Despite conflicting evidence, several studies have shown that improved survival is correlated with more lymph nodes removed in both node-negative and node-positive patients. The purpose of this study is to determine which patient, tumor, surgeon, and hospital characteristics are associated with the number of nodes excised in early breast cancer patients. METHODS: A random sample of 938 women with node-negative breast cancer was drawn from the Ontario Cancer Registry and the data supplemented with chart reviews. The extent of axillary dissection was studied by examining the number of nodes examined in relation to the patient, tumor, surgeon, and hospital factors. RESULTS: The mean number of lymph nodes excised was 9.8 (SD = 4.8; range, 1-31), and 49% of patients had >/=10 nodes excised. Lower patient age was associated with the excision of more lymph nodes (>/=10 nodes: 63% of patients <40 years vs. 38% of patients >/=80 years). Surgeon academic affiliation and surgery in a teaching hospital were highly correlated with each other and were significantly associated with the excision of >/=10 nodes. The number of nodes excised was not associated with any tumor factors, nor with the breast operation performed. These results were confirmed with multivariable models. CONCLUSIONS: Even though the number of lymph nodes found in the pathologic specimen can be influenced by factors other than surgical technique (e.g., number of nodes present, specimen handling, and pathologic examination), this study shows significant variation of this variable and an association with several patient and surgeon/hospital factors. This variation and the association with survival warrant further study and effort at greater consistency.     

Perceptions of nursing: a study involving nurses,nursing students,patients and non-nursing students

This paper describes a study of perceptions of nursing by nursing students, qualified nurses (United Kingdom and Spain), patients and non-nursing students. A survey method was used with a longitudinal panel element incorporating a 35-item version of the Nursing Dimensions Inventory translated into Spanish. Data were analysed using principal component analysis, congruence analysis, Mokken scaling, correlation, ANOVA, t-test and Cronbach's alpha. Patients may perceive nursing differently from nursing students, nurses (in the UK and Spain) and non-nurses. These findings are discussed in the context of nurse education and patient care.     

The coastal environment and human health: microbial indicators,pathogens, sentinels and reservoirs

Innovative research relating oceans and human health is advancing our understanding of disease-causing organisms in coastal ecosystems. Novel techniques are elucidating the loading, transport and fate of pathogens in coastal ecosystems, and identifying sources of contamination. This research is facilitating improved risk assessments for seafood consumers and those who use the oceans for recreation. A number of challenges still remain and define future directions of research and public policy. Sample processing and molecular detection techniques need to be advanced to allow rapid and specific identification of microbes of public health concern from complex environmental samples. Water quality standards need to be updated to more accurately reflect health risks and to provide managers with improved tools for decision-making. Greater discrimination of virulent versus harmless microbes is needed to identify environmental reservoirs of pathogens and factors leading to human infections. Investigations must include examination of microbial community dynamics that may be important from a human health perspective. Further research is needed to evaluate the ecology of non-enteric water-transmitted diseases. Sentinels should also be established and monitored, providing early warning of dangers to ecosystem health. Taken together, this effort will provide more reliable information about public health risks associated with beaches and seafood consumption, and how human activities can affect their exposure to disease-causing organisms from the oceans.     

Malignant melanoma in a patient with oculocutaneous albinism

BACKGROUND: Sun-induced malignancies (basal cell and squamous cell carcinomas) are common in oculocutaneous albinism, however, the incidence of malignant melanoma is a topic of controversy. OBJECTIVE: We have reviewed the literature and report a case of a woman with oculocutaneous albinism with an amelanotic melanoma of the anterior chest wall. RESULTS: There are only 26 previously reported cases (both case reports and African albino population studies) in 25 patients in the literature. A 27th case with immunohistochemical and ultrastructural evaluation is presented. CONCLUSIONS: It appears that melanoma, a malignancy for which sun exposure and light colouration are felt to be major risk factors, has a low incidence among a population that is both hypopigmented and often exposed to high levels of ultraviolet light. This low incidence is poorly understood and frequently disputed.     

Prevalence of risk factors for cardiovascular disease in Canadians 55 to 74 years of age: results from the Canadian Heart Health Surveys, 1986-1992

BACKGROUND: By 2016, the proportion of Canadians older than 65 years of age will increase to 16%, and there will be an increase in the absolute number of cases of cardiovascular disease in older Canadians. The Canadian Heart Health Surveys database provides information about this population upon which health policy related to cardiovascular disease can be based. This paper presents for the first time population-based data on the risk factors for cardiovascular disease in older Canadians. METHODS: Canadians from all 10 provinces participated in surveys of cardiovascular risk factors; health insurance registries were used as sampling frames. In each province, probability samples of 2200 adults 18 to 74 years old not living in institutions, on reserves or in military camps were asked to participate in interviews and to undergo testing at clinics for major risk factors for cardiovascular disease. RESULTS: A total of 2739 men (response rate 70%) and 2617 women (response rate 66%) aged 55 to 74 years participated in the survey and also provided follow-up clinical measurements at the clinic. Overall, 52% of participants were hypertensive, 26% had isolated systolic hypertension, and 30% had a total blood cholesterol level of 6.2 mmol/L or greater. Rates of current smoking were lower in women than men (17% v. 22%). Overall, 87% of men and 78% of women who were current smokers smoked at least 10 cigarettes per day. Only slightly more than half of participants exercised at least once a week for at least 15 minutes, and almost half had a body mass index of 27 or greater. In only 4% was no major risk factor for cardiovascular disease detected. INTERPRETATION: Significant numbers of older Canadians have one or more major risk factors for cardiovascular disease. Many of these risk factors are amenable to modification.     

Pulmonary lymphangitic spread of carcinoma: appearance on CT scans

Chest computed tomography (CT), including high-resolution CT with thin (1.5-mm) sections was used to evaluate proved (pathologically or clinically) lymphangitic spread (LS) of tumor in 12 patients. These appearances were compared with thin-section scans obtained in 11 healthy subjects. Thin-section CT demonstrated findings consistent with thickening of the normal lung interstitium. In all patients, thin sections showed an increase in the number of peripheral lines (1-2 cm in length) that were diffuse in generalized disease and localized in focal disease. Normal peripheral arcades were not increased in number, but the limbs forming the arcades were thickened in all patients. A diffuse increase in linear and curvilinear structures (reticular pattern) was seen toward the center of the lung. Polygonal structures 1-2 cm in diameter were seen in seven patients with LS but not in healthy subjects. Fissures were thickened in nine patients. Selected 1.5-mm-thick CT sections are recommended through abnormal areas (seen at CT or on chest radiographs) or if these are normal at three levels (midapex, hilus, and 3 cm above the diaphragm) when scanning patients with tumors known to cause LS.