Effect of neurotensin and epinephrine on sinus arrhythmia caused by burst stimulation of the vagus nerve

Administration of neurotensin against the background of sinus arrhythmia caused by burst stimulation of the vagus nerve in cats restores synchronization of the cardiac and vagal rhythms or modulates the proportion between them. This either stops the arrhythmia or changes its parameters. The effects of the peptide are similar to those of epinephrine and are abolished by β-adrenoreceptor blockage. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 5, pp. 494–497, May, 1997     

经食道心房调搏测定窦房结功能

对27例病窦综合征患者和42例正常对照组,经食道心房调搏,测定窦房结功能。发现病窦患者,窦房结恢复时间>1450ms;校正窦房结恢复时间≥550ms;窦房结传异时间>191ms;固有心率均明显低于正常对照组(R<0.01)。用阿托品,心得安进行功能性植物阻滞前、后观察,发现阻滞后各次参数在正常对照组中有明显降低,而病窦组则无明显差异。实验证明,经食道心房调搏方法是无创性窦房结功能检查的有效方法。     

蝶塞及毗邻关系的解剖对蝶窦手术重要性探讨

蝶窦居于颅底，毗邻结构复杂，常有变异。本文报告开展各类型蝶窦手术１２５例，并就蝶窦区域应用解剖对蝶窦手术的重要性，进行研究与探讨。     

脑静脉血栓病人的死亡因素分析(附5例分析)

目的分析脑静脉血栓(CVT)病人的死亡原因。方法回顾分析136例CVT病人中5例死亡病例的病因、临床表现、影像学资料、治疗经过及死亡原因。结果病死率为3.7%。2例在急性期死亡,3例在慢性期死亡。直接死亡因素均为脑疝;间接死亡因素为颅内多发性出血和多个部位的脑静脉血栓形成,死亡组(3.20±0.84)支静脉受累,存活组(2.09±1.00)支静脉受累(P=0.016)。而性别、年龄、确诊时间、癫疒间发作、病灶部位及治疗前颅内压等没有显著增加死亡的危险性。某些临床表现,如失语、运动障碍、精神症状及意识障碍与死亡有关,但其系多发性颅内出血及多个部位脑静脉血栓所致。结论CVT病人的直接死亡原因为脑疝,间接原因为多发性脑静脉血栓和颅内多发性出血。死亡不仅可以发生在急性期,也可以出现在慢性期。     

Sinoatrial Node Electrogram Studies in Patients with Sick Sinus Syndrome

Sinoatrial node electrogram (SNE) was recorded successfully in recent years, using transvenous electrode catheter. Via SNE and intratrialelectrogram (IEG), one could measure sinoatrial conduction time(SACT) directly, observe sinoatrial node (SN) potential changes in cadiac cycles, diagnose some sinus arrhythmias which couldn't be confirmed by surface ECG. All these could offer accurate evidence for differential diagnosis of sick sinus syndrome (SSS). The authors recommend a modified method for the location of the electrode catheter, by which one can increase success rate of obtaining stable SNE. Using this method, the authors recorded SNE in 10 cases with SSS successfully.     

三种去神经法对清醒大鼠动脉压力感受性反射功能的影响

目的：测定急、慢性去主动脉神经（ＡＤ）、去颈动脉窦神经（ＳＤ）、同时去主动脉和窦神经（ＳＡＤ）后大鼠动脉压力感受性反射对血压控制（ＡＢＲ－ＢＰ）和心动周期控制（ＡＢＲ－ＨＰ）的影响。方法：测定ＡＢＲ－ＢＰ采用阻断动脉压力感受性反射传出通路前后，比较机体对去氧肾上腺素升压反应面积差异的方法，所得数值与改良的Ｓｍｙｔｈ方法测定的ＡＢＲ－ＨＰ值进行比较。结果：（１）大鼠ＳＡＤ后ＡＢＲ－ＨＰ为零，且代偿不明显；而ＡＢＲ－ＢＰ约为３０％，且代偿明显；（２）ＳＤ后ＡＢＲ－ＢＰ与ＡＢＲ－ＨＰ无显著差异，而ＡＤ和ＳＡＤ后ＡＢＲ－ＢＰ的作用显著大于ＡＢＲ－ＨＰ的作用。结论：（１）大鼠的ＡＢＲ－ＨＰ传入冲动全部来自于主动脉弓和颈动脉窦的压力感受器，而ＡＢＲ－ＢＰ传入冲动大部分来自于这两处的感受器；（２）主动脉神经和窦神经感受传入在ＡＢＲ－ＢＰ中的作用是相当的，并有明显的相互代偿；而在ＡＢＲ－ＨＰ中，主动脉神经的作用比窦神经重要，其代偿能力也比窦神经显著。     

Stereotactically-guided craniotomy for cavernous angiomas presenting with epilepsy

Summary With the wider availability of magnetic resonance imaging cavernous malformations are being recognised with increasing frequency in those patients presenting with intractable epilepsy. Surgical resection is the treatment of choice. However, because these lesions are usually small and may be located in eloquent areas stereotactic resection should be considered. Stereotactically-guided resection of pathologically verified cavernous angiograms was performed in 10 patients in this series presenting with epilepsy (8 males, 2 females, mean age 32 years). Eight patients presented with medically intractable epilepsy (5 complex partial seizures, 3 grand mal seizures). Of the remaining patients one experienced multiple episodes of haemorrhage and the other headaches (with a non-diagnostic scan) both in association with epilepsy. Pre-operative localisation of the motor strip was determined in one case by functional MRI. Following resection of these lesions all patients experienced improved seizure control with a mean follow-up period of 22 months. The mean postoperative hospital stay was 5.1 days with no surgical complications recorded. We conclude that stereotactically-guided resection offers significant advantages in the management of cavernous malformations.Surgical indications for operative resection would include medically refractory epilepsy, repeated haemorrhage and those cases where there is diagnostic uncertainty.     

The influence of intravenous magnesium sulphate on the occurrence of atrial fibrillation after coronary artery by-pass operation

To examine the influence of (Mg) on hypomagnesaemia and atrialfibrillation (AF) following coronary artery by-pass surgery,140 consecutive patients were randomized to receive 70 mmolof magnesium sulphate intravenously (n = 69) or placebo (n =71). Serum magnesium concentrations fell to 0.77 ± 0.10mmol. l^–1 in the control group but rose to 1.09 ±0.17 mmol. l^–1 in the Mg group (P <0.001). The incidenceof AF was 29% in the Mg group and 26% in the placebo group (NS).The AF patients were older, more of them had had prior AF episodes,their sinus rates (SR) were slower (78 ± 10 vs 86 ±12 beats. Min^–1; P <0.01) and serum Mg concentrationshigher (0.89 ± 0.21 vs 0.11 mmol. ^l–1; P <0.05)The incidence of AF was 43% in the highest quartile of serumMg and 23% among the rest (P = 0.056). In patients experiencingAF during the first three post-operative days, serum Mg concentrationswere higher and SR slower on each day compared with non-AF patients.SR increased post-operatively less with high Mg levels (P =0.044). In the Mg group, serum Mg and SR were the only independentpredictors of AF. In conclusion, the incidence of post-operativeAF is not decreased with magnesium. High Mg levels are likelyto provoke AF probably by mechanisms that modify SR.     

MR imaging of dural arteriovenous malformations with ocular signs

Summary Four patients with dural arteriovenous malformation (AVMs) draining into the cavernous sinus, who presented ophthalmic manifestations, were studied by magnetic resonance (MR) imaging. In all patients signal decrease in the involved cavernous sinus was demonstrated in coronal spinecho (SE) imaging. It is attributable to rapid venous flow in the sinus, and this high velocity signal loss is a fairly pathognomonic finding in this condition. We stress the validity of MR imaging in the primary diagnosis of dural AVMs with ophthalmic symptoms.     

Reliability of Transesophageal Pacing in the Assessment of Sinus Node Function in Patients with Sick Sinus Syndrome

The purpose of this study was to find out whether transesophageal pacing could be utilized for assessment of sinus node function in patients with sick sinus syndrome (SSS). In 17 patients with SSS (study group) we compared the results of sinus node tests obtained both in the basal state and after pharmacological autonomic blockade by endocavitary stimulation and, 24 hours later, by transesophageal pacing. In another group of 17 patients with SSS (control group), we compared the results obtained by two endocavitary studies. In "study group", sinus cycle length (SCL) and corrected sinus node recovery time (CSRT) did not show significant differences between the two studies both in the basal state and after autonomic blockade, whereas sinoatrial conduction time (SACT) was more prolonged during esophageal pacing (P less than 0.01). In "control group", sinus node measures did not show significant differences between the two studies. In the "study group," the following coefficients of correlation were obtained in the basal state; SCL, r = 0.65, CSRT, r = 0.57, SACT, r = 0.52 and after autonomic blockade: SCL, r = 0.95, CSRT, r = 0.62 and SACT, r = 0.53. In the basal state, the correlation for SCL and CSRT between the two studies was lower in the "study group" than in the "control group" (P less than 0.05), whereas after autonomic blockade the correlation for sinus node measures did not show significant differences between the two groups of patients. These data suggest that transesophageal study influences the autonomic tone regulating the sinus node; however, it is not responsible for important variations in sinus node measures.(ABSTRACT TRUNCATED AT 250 WORDS)