Influence of Age on Linear and Nonlinear Measures of Autonomic Cardiovascular Modulation

Background: Age has been identified as an independent risk factor for cardiovascular diseases. In addition, autonomic imbalance toward sympathetic preponderance has been shown to facilitate the occurrence of heart disease. Here, we aimed to assess autonomic modulation of cardiovascular parameters during normal ageing applying well‐established linear and novel nonlinear parameters. Methods: Linear and nonlinear measures of heart rate variability and complexity as well as measures of QT interval variability and baroreflex sensitivity were obtained from a total of 131 healthy, medication‐free participants from a continuous age range between 20 and 90 years, who were allocated to three different age groups. Results: Heart rate variability and complexity significantly decreased with age, while regularity of heart rate time series increased. In addition, QT interval variability linearly increased with age, while baroreflex sensitivity showed a pronounced decrease. Overall, concerning effects of ageing, linear and nonlinear parameters showed equal differentiation between groups. Conclusion: These data indicate a shift of autonomic balance toward sympathetic predominance in higher age groups, limiting the reactiveness of the cardiovascular system to adjust to different demands and increasing the risk for developing tachyarrhythmias. Ann Noninvasive Electrocardiol 2010;15(2):165–174     

全科医生札记——布朗医生日记

家庭秘密Nick是我的一位病人,有好几年没看见他了。一个星期五的下午,我们正准备离开去度周末,Nick来到了诊所。他说:“医生,能耽误点儿时间给我看一下病吗?”他看上去十分烦躁不安,我说:“当然,进来吧。”他走进我的办公室,我随手把门关上了,Nick哭了。我只见过女士因为这种或     

Comparison of recovery patterns for patients undergoing coronary artery bypass grafting and minimally invasive direct coronary artery bypass in the early discharge period

The purpose of this pilot study was to compare the postoperative problems, evaluation and response of symptoms, and functional status (physiologic and psychosocial functioning) during the early recovery period (2, 4, and 6 weeks after surgery) in 35 individuals who underwent coronary artery bypass grafting (n=24) or minimally invasive direct coronary artery bypass (n=11). The most frequent postoperative problem reported by the coronary artery bypass grafting group was an incisional infection (either sternal or leg); 26% reported infection at 2 and 4 weeks, and 21% at 6 weeks after surgery. Respiratory problems (pleural effusion, pneumonia) were the second most frequently reported problem, reported by 10% of the subjects at 2 and 4 weeks and by 16% at 6 weeks. Other, less frequent problems were severe nervousness, rhythm problems, and pericarditis. Minimally invasive direct coronary artery bypass patients reported fewer postoperative or cardiac-related problems, as only 5% indicated a problem with heart failure at both 2 and 4 weeks, and 36% reported being very nervous or having emotional problems at 4 weeks. Unlike postoperative problems, there were numerous similarities in postprocedural symptoms between these two groups. Fatigue, shortness of breath, and pain were the major symptoms reported postdischarge by both groups in this study. In addition, sleeping problems were also fairly prevalent in the coronary artery bypass grafting group, which is understandable, considering the fatigue ratings. Physiologic and psychosocial functioning varied minimally between the two procedures. While there were many similarities in the recovery patterns of both groups, the occurrence of postprocedural problems and symptoms of these two patient groups should be considered by clinicians to further tailor patient education.     

Primary orbital melanoma masquerading as vascular anomalies

PURPOSE: To review two cases of primary orbital melanoma presenting like orbital vascular anomalies. METHODS: Retrospective review of clinical presentation, treatment, radiology and pathology for two patients under the care of the Orbital Clinic at Moorfields Eye Hospital. RESULTS: Both lesions presented with the appearance and behaviour of vascular anomalies. In one case, a spindle cell melanoma appeared to be a low flow vascular anomaly with a loculated secondary haemorrhage and, in the other case, a melanoma of soft parts was considered to be an arteriovenous malformation and responded partially to embolisation. CONCLUSION: Primary malignant melanoma may present as a secondary vascular lesion of the orbit and this very rare tumour should be considered in the differential diagnosis of any vascular anomaly.     

Encapsulated cell-based delivery of CNTF reduces photoreceptor degeneration in animal models of retinitis pigmentosa

PURPOSE: The objective of the present study was to evaluate the therapeutic efficacy of ciliary neurotrophic factor (CNTF) delivered through encapsulated cells directly into the vitreous of the eye in an rcd1 canine model of retinitis pigmentosa. The dose-range effect of the treatment was also investigated. METHODS: Polymer membrane capsules (1.0 cm in length and 1.0 mm in diameter) were loaded with mammalian cells that were genetically engineered to secrete CNTF. The cell-containing capsules were then surgically implanted into the vitreous of one eye of rcd1 dogs at 7 weeks of age, when retinal degeneration is in progress but not complete. The contralateral eyes were not treated. The capsules remained in the eyes for 7 weeks. At the end of the studies, the capsules were explanted, and CNTF output and cell viability were evaluated. The eyes were processed for histologic evaluation. RESULTS: In each animal, the number of rows of photoreceptor nuclei in the outer nuclear layer (ONL) was significantly higher in the eye that received a CNTF-secreting implant than in the untreated contralateral eye. No adverse effects were observed on the retina in the treated eyes. The explanted capsules produced a low level of CNTF. The cells in the capsules remained viable and densely distributed throughout. CONCLUSIONS: CNTF delivered through encapsulated cells directly into the vitreous of the eye protects photoreceptors in the PDE6B-deficient rcd1 canine model. Furthermore, sparing of photoreceptors appeared dose-dependent with minimum protection observed at CNTF doses of 0.2 to 1.0 ng/d. Incrementally greater protection was achieved at higher doses. The surgically implanted, cell-containing capsules were well tolerated, and the cells within the capsule remained viable for the 7-week implantation interval. These results suggest that encapsulated cell therapy may provide a safe and effective strategy for treating retinal disorders in humans.