Percutaneous ablation of atrial fibrillation: assessment of outcomes at 1-year follow-up.

OBJECTIVE: Current non-pharmacologic treatment strategies for atrial fibrillation (AF) involve discrete ablation of ectopic foci or isolation of the pulmonary vein (PV) ostia, which have been implicated in the genesis of this rhythm disorder. The aim of this study was to determine intermediate and long-term outcomes after percutaneous AF ablation and predictors of successful treatment. POPULATION AND METHODS: We studied 29 consecutive patients (72% male, mean age 52.3 +/- 13 years) who underwent percutaneous ablation of AF refractory to antiarrhythmic drug therapy. AF was idiopathic in 22 patients and the remaining 7 patients were hypertensive. Six patients had permanent AF and the others had recurrent paroxysmal AF (with at least 1 episode a week). Left atrial size was 40.3 +/- 6.1 mm. A total of 35 ablation procedures were performed, 12 using the focal ablation technique and 23 by PV isolation. Six patients underwent a redo procedure. Patients were evaluated at 1-year follow-up (symptoms, medication, ECG and Holter monitoring). Predictors of successful treatment were identified among baseline clinical variables (age, gender, hypertension), LA size, AF sub-type, ablation technique, and number of isolated PV, using multivariable logistic regression. RESULTS: At 1-year follow-up, 20 patients presented sinus rhythm (69%), of whom 7 were taking antiarrhythmic drugs and remained free of AF relapse. Out of the total of 35 procedures, 2 immediate complications occurred: pericardial tamponade in one patient and right phrenic nerve palsy in another. Predictors of long-term success were absence of a prior history of hypertension and isolation of at least three PV (p = 0.01 for both independent predictors). CONCLUSION: Two out of three patients who underwent AF ablation presented sinus rhythm one year after the intervention. Isolation of at least three PV and idiopathic etiology are independent predictors of successful treatment.     

离子色谱法同时测定葡萄糖酸钙及其杂质(Cl-,SO42-)的含量

本文采用Waters ILC-1离子液相色谱仪,IC-PAK A50×4.6mm色谱柱,pH6.61×10^-3mol/L邻苯二甲酸溶液为流动相,430型电导检测器检测,由外标法和外标单点校正法同时测定了葡萄糖酸钙及其杂质(Cl^-,SO₄^2-)的含量。方法简便、快速,测定结果与中国药典法一致。外标法和外标单点校正法测定Cl^-,SO₄^2-的平均回收率为100.8%和100.2%,相关系数分别为0.9951(n=8)和0.9961(n=8)。     

The predictive value of cranial ultrasound and of somatosensory evoked potentials after nerve stimulation for adverse neurological outcome in preterm infants

Thirty-nine preterm infants were studied to compare the predictive value of somatosensory evoked responses (SEPs) following median-nerve and posterior tibial-nerve stimulation with the predictive value of cranial ultrasound. With regard to the SEP, a normal median-nerve response was by no means a guarantee of a normal outcome. A normal posterior tibial-nerve response, however, almost guaranteed a normal outcome, but the test was very time consuming and the number of false positive responses was high (sensitivity. 95.6%, specificity 50%). The presence of parenchymal involvement, either due to a haemorrhage or cystic leukomalacia predicted cerebral palsy with a sensitivity of 95.6% and a specificity of 68.5%. The combination of an abnormal posterior tibial response and the presence of parenchymal brain lesions had the best predictive value with a sensitivity of 91.3% and a specificity of 81.2%. These results show that, although posterior tibial-rferve responses have a better predictive value than median-nerve responses, these values were lower than that of cranial ultrasound. The best prediction was obtained when a combination of posterior-tibial responses and cranial ultrasound was used.     

Enhanced histamine-mediated contraction of rabbit penile dorsal artery in diet-induced hypercholesterolemia

The present study was designed to establish whether penile dorsal arteries isolated from rabbits fed a high cholesterol diet show an enhanced contractile and/or impaired vasodilator response to histamine, and to characterize the histamine receptor subtype involved through in vitro isometric techniques. New Zealand White rabbits were fed a normal diet or a 1% cholesterol diet for 16 weeks. Arteries from cholesterol-fed rabbits retained the ability to relax in response to acetylcholine, whereas histamine and noradrenaline induced a greater contraction response compared to that observed in controls. In both groups, histamine-induced contraction was unaffected by the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME), its precursor L-arginine or the cyclooxygenase inhibitor indomethacin. Treatment of arterial rings in the control and hypercholesterolemia groups with the H1 receptor antagonist, mepyramine, unmasked a vasodilation response to histamine. This was followed by contraction at higher concentrations showing a leftward displacement of the histamine curve compared to controls. The histamine receptor that induced contraction in preparations from the hypercholesterolemic animals was of the H1 subtype, whereas the receptor involved in histamine-induced relaxation was H2. The affinity of histamine receptor agonists was comparable to their effects in control animals, and receptor antagonists showed the same potency in both groups. Our findings indicate a preserved endothelial function and enhanced contraction in response to histamine in penile dorsal arteries, probably due to a change in the sensitivity of the contractile machinery of smooth muscle but not a mechanism mediated by a receptor.