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目的对儿童血管迷走性晕厥(VVS)的传统诊断程序与新诊断程序进行卫生经济学评价。方法采用回顾分析方法,根据不同的诊断程序(即传统诊断程序和新诊断程序),将1995年1月至2005年5月北京大学第一医院儿科确诊的81例VVS患儿分为2组,分别计算其就诊费用、检查费用、住院日、确诊日等,运用经济学最小成本分析法进行评价。结果新诊断程序的平均就诊费用比传统诊断程序少耗费1668.80元;新诊断程序的平均就诊检查费用比传统诊断程序少耗费1413.30元。结论新诊断程序对确诊儿童血管迷走性晕厥具有良好的经济学效益,值得临床推广。     

Syncope in children with Tourette's syndrome treated with guanfacine.

We report on 4 children who experienced a syncopal episode while being treated with guanfacine without any other evident cause. Syncope appears to be an uncommon side effect of guanfacine and is probably due to drug-induced hypotension or bradycardia.     

A case of nocturnal fainting: supine vasovagal syncope.

Supine loss of consciousness is a relatively rare occurrence prompting investigations for underlying causes as diverse as cardiac arrhythmia, hypoglycaemia and nocturnal epilepsy. Neurally mediated syncope is rarely implicated as the cause of symptoms in supine loss of consciousness because of the absence of orthostatic stress and gravitational relative preservation of cerebral perfusion, but we report here on a case of recurrent, atypical and troublesome vasovagal syncope occurring at night while supine. Diagnosis aided by head-up tilt table testing and conservative management brought about complete resolution of symptoms.     

Cerebellar tumour presenting with pathological laughter and gelastic syncope

There is no report of patients in whom pathological laughter, a rare condition characterized by uncontrollable episodes of laughter usually triggered by unrelated stimuli, was ever closely associated with a loss of consciousness overtly linked with the onset of such uncontrollable laughter, also referred to as a gelastic syncope. A 53-year-old man presented with a 4-month history of syncope following intense and uncoordinated laughter. Physical and neurological examination was normal and the patient had no other typical cerebellar signs. We found a mass in the cerebellar vermis abutting the floor of the fourth ventricle, which upon histological examination after surgery proved to be an ependymoma. We emphasize that pathological laughter and gelastic syncope could represent unique and sole features of a cerebellar disorder.     

CLINICAL IMPLICATIONS OF ELECTROPHYSIOLOGY STUDY FINDINGS IN PATIENTS WITH CHRONIC BIFASCICULAR BLOCK AND SYNCOPE

Electrophysiology study was performed in 93 patients with bifascicular block and unexplained syncope. Clinical evidence of organic heart disease was present in 33 (35%). Electrophysiological abnormalities were detected in 45 patients (48%). Of these, 36 had distal conduction disease, including 28 with an HV interval > 55 ms (mean 76.4 ms), and eight who developed infraHisian block following either intravenous procainamide (four) or atrial pacing (four). Sick sinus syndrome was evident in six patients and a further two had carotid sinus hypersensitivity. Sustained monomorphic ventricular tachycardia (VT) was induced in only three patients, two of whom also had prolonged HV interval. Among the 93 patients, 45 had therapy which was guided by positive findings at electrophysiology study (Group 1). Of these, 42 received permanent pacemakers, two were treated with combined permanent pacing and antiarrhythmic drug therapy, and one was treated with antiarrhythmic drug alone. In addition, eight patients without electrophysiologic abnormalities were treated empirically by pacing (Group 2). Finally, 40 patients without electrophysiologic abnormalities received no specific therapy (group 3). At a mean follow-up of 39 months (range two-125 months), recurrence of syncope had occurred in 4% of Group 1 patients, and 25% of Group 3 patients (p < 0.05). No patient in Group 2 had had recurrence. Total mortality was 40%, including 47% of patients in Group 1, 25% of Group 2, and 35% of Group 3. Death was sudden in seven patients. We concluded that among patients with bifascicular block and syncope, therapy directed by findings at electrophysiology study was associated with symptomatic improvement, but mortality was not significantly influenced. Patients with no electrophysiological abnormality have a high recurrence of syncope which may relate either to undetected bradyarrhythmia or ventricular tachycardia. These results highlight some limitations in current assessment, including, for programmed ventricular stimulation, significant differences in both stimulation protocols and the definition of ventricular tachycardia.     

Superior vena cava syndrome and syncope in an implantable cardioverter defibrillator recipient.

We describe the case of a recipient of an implantable cardioverter defibrillator with multiple syncopal episodes due both to superior vena cava obstruction and electrical instability. These complications occurred in the presence of two transvenous implantable cardioverter defibrillator leads. The patient has been managed conservatively with anticoagulants and new antiarrhythmic drugs with improvement in both his clinical problems.     

Near-infrared spectrophotometry determined brain oxygenation during fainting

During orthostatic hypotension we evaluated whether presyncopal symptoms relate to a reduced brain oxygenation. Nine subjects performed 50° head-up tilt for 1 h and eight subjects were followed during 2 h of supine rest and during 1 h of 10° head-down tilt. Cerebral perfusion was assessed by transcranial Doppler determined middle cerebral artery blood velocity (MCA v_mean), while brain blood oxygenation was assessed by near-infrared spectrophotometry determined concentration changes for oxygenated (ΔHbO₂) and deoxygenated haemoglobin and brain cell oxygenation by the oxidized cytochrome c concentration (ΔCytO₂). During head-up tilt, six volunteers developed presyncopal symptoms and mean arterial pressure (88 (78–103) to 68 (57–79) mmHg; median and range), heart rate (96 (72–111) to 65 (50–107) beats min^?1), MCA v_mean (59 (51–82) to 41 (29–56) cm s^?1), ΔHbO₂ (by ?5.3 (?3.0 to ?14.8) μmol l^?1) and ΔCytO₂ were reduced (by ?0.2 (?0.1 to ?0.4) μmol l^?1; P < 0.05). During tilt down the cardiovascular variables recovered immediately and ΔHbO₂ increased to 2.2 (?0.9–12.0) mmol L^?1 above the resting value and also ΔCytO₂ recovered. In the nonsyncopal head-up tilted subjects as in the controls, blood pressure, heart rate, MCA v_mean and brain oxygenation indices remained stable. The results suggest that during orthostasis, presyncopal symptoms relate not only to cerebral hypoperfusion but also to reduced brain oxygenation.     

An approach to some dilemmas and complications of office oral surgery*

This article reviews an eclectic collection of problems. There is no particular reason why any one of them was chosen other than that they are more likely to occur in the course of practice than some other complications such as an oro-antral fistula or trauma to the lingual nerve or tissue emphysema. These latter and some other predicaments were discussed in the course of the talks given by the author at the 28th Australian Dental Congress in March 1995. The problems discussed in this paper are:

• 1 1. Dentoalveolar abscess anaesthesia.
• 2 2. Inability to obtain effective anaesthesia.

The complications:

• 2 1. Post-extraction haemorrhage.
• 2 2. Syncope.
• 3 3. Postoperative infection.