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41.
Mechanisms of Undersensing by a Noise Detection Algorithm That Utilizes Far‐Field Electrograms With Near‐Field Bandpass Filtering 下载免费PDF全文
JAYANTHI N. KONERU M.B.B.S. CHARLES D. SWERDLOW M.D. F.H.R.S. SYLVAIN PLOUX M.D. Ph.D. PARIKSHIT S. SHARMA M.D. M.P.H. KAROLY KASZALA M.D. Ph.D. ALEX Y. TAN M.D. JOSE F. HUIZAR M.D. PUGAZHENDI VIJAYARAMAN M.D. F.H.R.S. DAVID KENIGSBERG M.D. F.H.R.S. KENNETH A. ELLENBOGEN M.D. F.H.R.S. 《Journal of cardiovascular electrophysiology》2017,28(2):224-232
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FERNANDO E.S. CRUZ MARCIO FAGUNDES SILVIA BOGHOSSIAN JOSE CARLOS RIBEIRO LUTGARDE VANHEUSDEN IVAN G. MAIA 《Pacing and clinical electrophysiology : PACE》1996,19(6):993-998
The coexistence of a pamsystolic focus, tachycardia dependent right bundle branch aberrancy, and an AV accessory pathway is reported here. This condition was present in a 40-year-old man, which led to an incessant AV reciprocating tachycardia. Further electrophysiological study revealed that the parasystolic focus was located somewhere in the His bundle; endocardial mapping disclosed a right posterior accessory pathway. Radiofrequency current was delivered at the atrial level of the right posterolateral AV groove and successfully ablated the accessory pathway, leading to a dramatic improvement in cardiac function. In conclusion, the recognition of the electrophysiological mechanism of incessant Supraventricular tachycardia was of crucial importance for the therapy decision. A definitive intervention using radiofrequency catheter ablation should be considered early and not postponed in patients with tachycardia-induced cardiomyopathy. 相似文献
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The prevalence of early and severe atherosclerotic coronary disease is much higher in diabetic patients than in their nondiabetic counterparts. The incidence of acute coronary syndrome is also disproportionately higher in this population. This difference has generally been attributed to a much higher prevalence of traditional risk factors such as hypertension and dyslipidemias in diabetic patients; however, a clear explanation is yet to be found. Vascular injury and growth factors are increased in these individuals. Metabolic and biochemical abnormalities such as glycosylation and oxidation of low density lipoprotein (LDL) and the formation of "large" very low density lipoprotein (VLDL) promote the accumulation of monocytes and macrophages, leading to the formation of foam cells. Glycosylation of high density lipoprotein (HDL) impairs its antiatherogenic action. These abnormalities may enhance the extracellular (core) lipid content of the atherosclerotic plaque, rendering it softer. An augmented inflammatory response also appears to take place in the atherosclerotic plaque of diabetic patients. There is a strong chemotaxis for monocytes and macrophages mediated by glycoxidation. These cells induce the secretion of interleukin-1 and cachectin/tumor necrosis factor, which in turn inhibit nitric oxide activity, leading to detrimental action of mast cells. Diabetic patients also have an enhanced vasoconstrictive response. Significant platelet, coagulation, and fibrinolytic abnormalities are also present in these individuals, which favor a relatively hypercoagulable state. Plaque stress due to enhanced tensile and compression forces appears to be increased in diabetic patients. 相似文献
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FLÁVIO QUEIROZ-TELLES M.D. KHATIA S. PURIM M.D. JOSE N. FILLUS M.D. GISELE F. BORDIGNON B.S. ROSÁNGELA P. LAMEIRA B.S. JAN VAN CUTSEM GERT CAUWENBERGH PH.D. 《International journal of dermatology》1992,31(11):805-812
The efficacy and tolerability of itraconazole in chromoblastomycosis due to Fonsecaea pedrosoi were evaluated in a non-comparative open clinical trial in 19 Brazilian patients with histopathologically and mycologically proven active chromoblastomycosis. Patients were classified in terms of severity and received itraconazole at the dosage of 200 to 400 mg per day until previously described criteria of cure have been reached. Clinical, mycologic, histopathologic, and laboratory evaluations were performed before, during, and after therapy. The plasma levels of itraconazole and the in vitro susceptibility of the isolates were determined in 15 cases. Clinical and biologic cure were achieved by eight patients (42%) having mild to moderate disease, after a mean duration of therapy of 7.2 months (3.2-29.6 months). Sterile scarred lesions were observed in a post-therapy follow-up lasting on average 9.6 months that was carried out in this subgroup. Clinical cure alone occurred after a mean period of 25.1 months of treatment (16-30.5 months) in seven patients (36%) with moderate to severe disease. Finally, clinical improvement was obtained in four patients (21%) with severe lesions after a mean treatment time of 17.6 months (10.7-22.5 months). All patients responded favorably to itraconazole therapy. No significant side effects nor biochemical alteration during this trial were important enough to interrupt the treatment. Our results support those of previous trials, suggesting that itraconazole is an effective compound against chromoblastomycosis due to Fonsecaea pedrosoi. 相似文献
48.
The Architecture of the Atrial Musculature Between the Orifice of the Inferior Caval Vein and the Tricuspid Valve: The Anatomy of the Isthmus 总被引:1,自引:0,他引:1
JOSE ANGEL CABRERA M.D. DAMIAN SANCHEZ-QUINTANA M.D. † SIEW YEN HO PH.D. ‡ ALEONSO MEDINA M.D. ROBERT H. ANDERSON M.D. ‡ 《Journal of cardiovascular electrophysiology》1998,9(11):1186-1195
Anatomy of Electrophysiologic Isthmus. Introduction : Electrophysiologists recognize a so-called "isthmus" in the right atrium through which passes the reentrant circuit of common atrial flutter. Ablative lesions placed in this narrow channel have proved effective in breaking the circuit. To the best of our knowledge, however, no study has been performed to establish the arrangement and orientation of the atrial myocardial fibers in this crucial area.
Methods and Results : We examined 28 normal heart specimens, identifying a quadrilateral area composed of three morphologic sectors between the inferior caval vein and the tricuspid valve confluent superiorly with the triangle of Koch. Within this quadrilateral, there are constant recesses, or sinuses, inferior and lateral to the orifice of the coronary sinus. The inferior isthmus measured an average of 31 ± 4 mm (range 19 to 40). Gross examination identified marked differences in the atrial wall forming the quadrilateral. A smooth anterior component forming the vestibule of the tricuspid valve was found in all the hearts, but variations in the remaining sectors were seen in ten specimens. The usually membranous posterior sector was noticeably muscular in three specimens, while the middle, trabecular sector was more membranous in five specimens. We demonstrated the orientation of the subendocardial atrial fibers by dissection in 14 specimens, revealing a relatively constant overall pattern in eight specimens and variations in fiber orientation in the remaining specimens.
Conclusion : There are considerable anatomic variations in the atrial wall that comprises the so-called isthmus. The presence of recesses and membranous areas in some hearts and the variations in arrangement of the subendocardial fibers are relevant in improving understanding of conduction in this area. 相似文献
Methods and Results : We examined 28 normal heart specimens, identifying a quadrilateral area composed of three morphologic sectors between the inferior caval vein and the tricuspid valve confluent superiorly with the triangle of Koch. Within this quadrilateral, there are constant recesses, or sinuses, inferior and lateral to the orifice of the coronary sinus. The inferior isthmus measured an average of 31 ± 4 mm (range 19 to 40). Gross examination identified marked differences in the atrial wall forming the quadrilateral. A smooth anterior component forming the vestibule of the tricuspid valve was found in all the hearts, but variations in the remaining sectors were seen in ten specimens. The usually membranous posterior sector was noticeably muscular in three specimens, while the middle, trabecular sector was more membranous in five specimens. We demonstrated the orientation of the subendocardial atrial fibers by dissection in 14 specimens, revealing a relatively constant overall pattern in eight specimens and variations in fiber orientation in the remaining specimens.
Conclusion : There are considerable anatomic variations in the atrial wall that comprises the so-called isthmus. The presence of recesses and membranous areas in some hearts and the variations in arrangement of the subendocardial fibers are relevant in improving understanding of conduction in this area. 相似文献
49.
ELIZABETH TRABKA-JANIK M.D. Ph.D. WANDA COOMBS B.S. LARRY F. LEMANSKI PH.D. MARIO DELMAR M.D. PH.D. JOSE JALIFE M.D. 《Journal of cardiovascular electrophysiology》1994,5(2):125-137
Gap Junction Proteins in the Sinoatrial Node. Introduction: Gap junction proteins are thought to form the low resistance pathways that connect neighboring cells within the sinoatrial node, and to mediate pacemaker synchronization.
Methods and Results: We have carried out microelectrode mapping experiments of the hamster sinoatrial region to localize the primary pacemaker area for subsequent light, electron, and immunofluorescence microscopic studies aimed at testing the hypothesis that the major cardiac gap junction protein (connexin43) is present in such an area. The site of earliest activation is unifocal and the pattern of activation, obtained In multiple sequential microelectrode recordings of the Sinoatrial region, is qualitatively similar to that previously described for other species. However, quantitatively, the impulse transmission time from the primary pacemaker area to the crista (sulcus) terminal's in the hamster sinoatrial node is about 50% briefer than that of the guinea pig and five times faster than that of the rabbit. Immunolocalization studies in the hamster sinoatrial node using anti-connexin43 antisera demonstrated specific staining at the areas of cell-to-cell apposition and suggested that the apparently high degree of electrical coupling in this tissue is the result of abundant connexin43 expression. The immunofluorescence data were supported by light microscopic studies, which demonstrated the typical morphologic characteristics of sinus nodal cells in the pacemaker area. In addition, an electron microscopic study of the sinoatrial region revealed the presence of gap junctions in the junctional complex at areas of cell-to-cell contact.
Conclusion: Our results demonstrate that cells in the sinoatrial region of the hamster heart are electrically well coupled and strongly suggest that such coupling is mediated by gap junctional channels formed by connexin43. 相似文献
Methods and Results: We have carried out microelectrode mapping experiments of the hamster sinoatrial region to localize the primary pacemaker area for subsequent light, electron, and immunofluorescence microscopic studies aimed at testing the hypothesis that the major cardiac gap junction protein (connexin43) is present in such an area. The site of earliest activation is unifocal and the pattern of activation, obtained In multiple sequential microelectrode recordings of the Sinoatrial region, is qualitatively similar to that previously described for other species. However, quantitatively, the impulse transmission time from the primary pacemaker area to the crista (sulcus) terminal's in the hamster sinoatrial node is about 50% briefer than that of the guinea pig and five times faster than that of the rabbit. Immunolocalization studies in the hamster sinoatrial node using anti-connexin43 antisera demonstrated specific staining at the areas of cell-to-cell apposition and suggested that the apparently high degree of electrical coupling in this tissue is the result of abundant connexin43 expression. The immunofluorescence data were supported by light microscopic studies, which demonstrated the typical morphologic characteristics of sinus nodal cells in the pacemaker area. In addition, an electron microscopic study of the sinoatrial region revealed the presence of gap junctions in the junctional complex at areas of cell-to-cell contact.
Conclusion: Our results demonstrate that cells in the sinoatrial region of the hamster heart are electrically well coupled and strongly suggest that such coupling is mediated by gap junctional channels formed by connexin43. 相似文献
50.
LLOBET JUAN M.; COLOMINA M. TERESA; SIRVENT JUAN J.; DOMINGO JOSE L.; CORBELLA JACINTO 《Toxicological sciences》1995,25(1):45-51
The reproductive toxicology of aluminum was studied in mice.Adult male mice were treated intraperitoneally with aluminumnitrate at doses of 0, 50, 100, and 200 mg/kg/day for 4 weeksbefore mating with untreated females. Decreased body weightwas seen in all aluminum-treated groups. Decreased pregnancyrate was observed in the females mated with males previouslytreated with 100 or 200 mg/kg/day of aluminum nitrate. High-dosemale mice showed significantly decreased testicular and epididymalweights, as well as significant decreases in testicular andspermatid counts and epididymal sperm counts. Spermatid countswere also reduced at 100 mg/kg/day. However, the sperm motilitywas unaffected, and the percentages of morphological normalspermatozoa in all mice exposed to aluminum were comparableto the values in control mice. Histological changes, includingnecrosis of spermatocytes/spermatids, were observed in the testesof male mice treated with 100 and 200 mg/kg/day of aluminumnitrate, whereas the tubu lar diameters were unaffected by aluminumadministration. The current study demonstrates adverse effectsof parenteral aluminum exposure on the mouse male reproductivesystem. The "no observable adverse effect level" (NOAEL) was50 mg/kg/day. 相似文献