Objective To study the electrophysiologic characteristics of atrial-ventricular reentrant tachycardia(AVRT)characterized by paroxysmal occurrence that slow atrioventricular accessory pathway participatesin.Methods Twenty-one cases were chosen from patients receiring radiofrequency ablation therapy in Peking University People's Hospital from July in 1999 to January of 2005.The patients with slow atrioventricular accessory pathways diagnosed correctly were divided into two groups with paroxysmal tachycardia and permanent tachycardia in terms of the occurrent frequence of AVRT.The electrophysiologic features of AVRT of two groups were contrastively analyzed.Results Compared with the group of permanent AVRT,it was found that antidromic refractory period of slow atrioventricular accessory pathways was longer[(359?46)ms vs (318?31)ms,P

Objective To investigate the protective effect of transfecting bone morphogenetic protein-7 (BMP-7) on cultured neonatal rat cardiomyocytes against hypoxia-reoxygenation injury. Methods Neonatal rat cardiomyocytes were cultured. The pcDNA-rrBMP7 was introduced into cardiomyocytes by Fugene 6.0 transfection method. The cardiomyocytes were divided into three groups: control group (group C), hypoxia-reoxygenation group (group HR) and gene transfecting group (group BT). Trypan blue exclusion test was performed to detect cell viability. The activity of lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) was assayed to evaluate cell injury. For evaluating the cell antioxidant ability, the activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) were determined by colorimetric assay. Fluo-3 labeling method and confocal laser scanning microscopy were used to observe the change in intracellular calcium. Results The results showed that after 120 min of simulated ischemia followed by 240 min of reperfusion, cell pulsation rate was decreased, the activity of LDH, CPK and the trypan blue uptake rate were increased. As compared with the group C, SOD activity decreased and the content of MDA increased in Group HR. Compared with Group HR, the SOD activity increased and the content of MDA decreased in group BT. Treatment with BMP-7 gene transfecting led to a decrease of i content in cardiomyocytes, showing that overloading of i induced by hypoxia-reoxygenation was prevented (P

1.9?V and 95% confidence interval was 1.52-2.41?V.There was significant differences among the groups(P

Objective To investigate the association between syncope and transient suppression of sinoatrial node in patients with preexcitation syndrome and paroxysmal supraventricular tachycardia (PSVT).Methods Twelve patients (male 8,female 4;age range:19-49 years) were enrolled due to WPW(Wolff-Parkinson-White) syndrome and syncope when the tachycardia terminated.The function of sinoatrial node was evaluated with clinical electrophysiologic study,and then radiofrequency catheter ablation (RFCA) or antitachycardia pacemaker were optimized for the patients with a follow-up of 2 to 5 years.Results Electrocardiographic features of the 12 patients were: ventricular preexcitation (type A in 7 and type B in 5) and long pause when tachycardias ended up.Electrophysiologic study revealed the function of sinoatrial node was normal.Four patients received antitachycardia pacing therapy,5 underwent RFCA,and 3 received both.The 2 to 5 years follow-up found no relapse of PSVT associated syncope.Conclusion Transient suppression of sinoatrial node might explain the mechanism of syncope with preexcitation and PSVT.However,the reason why such a small group of patients differ from the majority of preexcited cases in clinical course remains to be unsettled.The first choice of prevention and treatment for these patients should be eliminating PSVT.Conventional pacemaker implantation for preventing syncope seems to be unnecessary.

Objective To study the protective effects of low frequency electric stimulation at bilateral mastoid processes on the focal cerebral lesion induced by ischemia-reperfusion in rats. Methods Focal cerebral ischemia in rats was produced by 2 hours of the middle cerebral artery occlusion (MCAO) and 24 hours reperfusion. The neurological deficits scale was used to evaluate and screen the rats for tests. The cerebral water content was determined by wet/dry weighing method. The infarct volume was measured by 2,3,5-triphenyltetrazolium chloride (TTC) staining technique and image analysis instrument. The activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in ischemic tissue of brain were analyzed. Results Compared with the control group, the severity of cerebral edema in the treatment group, apart from the emergency group,was lessened(P

Objective To investigate the current situation of prediabetic self-efficacy of middle aged and elderly prediabetes and its influencing factors. Method Unified questionnaires were used to investigate the self-efficacy of 234 prediabetes and its influencing factors. Results The total scores of self-efficacy in the middle-aged and elder prediabetes were at moderate level. The score of the older patients was significantly higher than that of the middle aged (P<0.01). Multiple regression analysis showed that marital status and disease knowledge were main factors impacted their self-efficacy of the middle aged and family history of diabetes and the disease knowledge were the main factor affecting the self-efficacy of the elderly prediabetes. Conclusions The self-efficacy of middle-aged and elderly prediabetes is at middle level. Nurses need to enhance the knowledge of the prediabetic patients, attaching more attention to those not in marriage and those without history of diabetes so as to strengthen their self-efficacy.

Objective\ To evaluate the efficacy of atrial lead implantation during atrial fibrillation.Methods\ In 10 patients(group A),the atrial leads were implanted during atrial fibrillation and the sensing and pacing parameters before and after restoring to sinus rhythm were compared with the parameters of patients whose atrial leads were implanted during sinus rhythm (group B).Results\ During follow-up,the sensing and pacing parameters were measured,and there were no significant difference between group A and B.In group A,mean atrial potential amplitude during atrial fibrillation was correlated with the telemetered atrial potential amplitude during sinus rhythm.Conclusion\ Atrial lead implantation during atrial fibrillation is feasible.

Objective Accelerated junctional rhythm (AJR) always occur during slow pathway catheter ablation for atrioventricular nodal reentrant tachycardia (AVNRT), the clinical significance of it has not been gotten in agreement. The aim of this study is to search for an association between AJR and ablation target site or tachycardia recurrence.Methods The data of 247 patients with AVNRT who received radiofrequency ablation procedure during April 1995 to October 1999 was analyzed. All these people were divided into two groups (212 patients in the successful ablation group or group 1, 35 patients in the recurrence group or group 2). The AJR was divided into two distinct pattern:type Ⅰ(continuous AJR that persisted until the end of energy delivery) and type Ⅱ (intermit AJR alternated with sinus rhythm during slow pathway ablation, which was eliminated immediately when stopping energy delivery ). Results\ The results showed that patients in group 1 exhibited better AJR response, most of them were seen with type Ⅱ AJR. However most of the people in group 2 had no AJR response throughout energy delivery , few of them had type Ⅰ AJR response. The AJR response of group 1 started relatively earlier than that of group 2(3 2?1 8 vs 5 7?2 5 ,P

Objective The aim of our study is to differentiate left atrial from right atrial tachycardia on the basis of P wave configuration during focal atrial tachycardia (AT).Methods Thirty-three patients with focal atrial tachycardia who had undergone successful radiofrequency catheter ablation were considered for inclusion in the study . Site of origin was the left atrium in 10 patients, and right atrium in 23 patients . The surface 12-lead ECG recordings during atrial tachycardia were reviewed in all patients. We analyzed the correlativity between P wave configuration and left atrial tachycardia.Results The specificity of negative P wave in lead I and aVL that indentifed a left atrial focus was 100% and 95% respectively, but the sensitivity was only 30% and 50% respectively. The specificity and sensitivity of positive P wave in V 1 that predicted a left atrial focus was 87% and 80%,respectively.Conclusion It is possible to predict the site of origin of focal atrial tachycardia by analyzing its P wave configuration,,and may be helpful for preparation before ablation.

Objective To investigate the method for benefit management of medical equipment. Methods By analyzing the actuality of equipment management, problems were founded and the solutions were discussed. Results The problems are the repeated purchase of medical equipment, less use in some equipments, dis- accordance among equipment, card and account. Conclusions In hospital, medical equipment play a crucial role in medical affairs, teaching and scientific research, and can bring prominent economic benefit. Enhancing the scientific management in medical equipment, emphasizing the details, procedure and scientific investigation in management can promote the using efficiency, ensure the reasonable match in equipment as much as possible in order to make the hospital sustainable development.