Electrocardiography in the patient with the Wolff-Parkinson-White syndrome: diagnostic and initial therapeutic issues

The Wolff-Parkinson-White syndrome (WPW), estimated to occur in approximately 0.1% to 3% of the general population, is a form of ventricular preexcitation involving an accessory conduction pathway. The definition of WPW relies on the following electrocardiographic features: (1) a PR interval less than 0.12 seconds (2) with a slurring of the initial segment of the QRS complex, known as a delta wave, (3) a QRS complex widening with a total duration greater than 0.12 seconds, and (4) secondary repolarization changes reflected in ST segment-T wave changes that are generally directed opposite (discordant) to the major delta wave and QRS complex changes. The accessory pathway bypasses the atrioventricular (AV) node, creating a direct electrical connection between the atria and ventricles. The majority of patients with preexcitation syndromes remain asymptomatic throughout their lives. When symptoms do occur they are usually secondary to tachyarrhythmias; the importance of recognizing this syndrome is that these patients may be at risk to develop a variety of supraventricular tachyarrhythmias which cause disabling symptoms and, in the extreme, sudden cardiac death. The tachyarrhythmias encountered in the WPW patient include paroxysmal supraventricular tachycardia (both the narrow QRS and wide QRS complex varieties), atrial fibrillation, atrial flutter, and ventricular fibrillation. Diagnostic and urgent, initial therapeutic issues based on initial electrocardiographic information are presented via 5 illustrative cases.     

Paradoxical preexcitation during cryoablation of a concealed parahisian accessory pathway

A 16‐year‐old male presented with an orthodromic atrioventricular reentrant tachycardia over a concealed parahisian accessory pathway (AP). Cryoablation of the AP resulted in transient manifestation of a fully preexcited sinus rhythm of parahisian AP morphology. Potential causes for the paradoxical preexcitation include inadvertent atrioventricular nodal block, sourse‐sink mismatch, as well as the activation of a dormant AP capable of anterograde conduction.     

预激综合征伴房颤的急诊复律

目的探讨预激综合征伴房颤的急诊复律方法与效果。方法总结分析１９例预激综合征伴房颤的急诊治疗措施与疗效。结果用普罗帕酮１０例、普鲁卡因胺６例、利多卡因８例,分别有７例、４例和３例转为窦性心律;２例用维拉帕米、１例用阿拉明治疗均无效;１例静注毛花甙丙后症状加重;１例自行转为窦性心律;３例药物复律无效及１例来诊时伴休克、肺水肿者用１００～１５０Ｊ直流电复律,均一次成功转为窦性心律。结论普罗帕酮、普鲁卡因胺和利多卡因是常规使用的复律药物,而以前者为首选;药物复律无效或伴血流动力学障碍者宜用直流电复律。     

Recognizing and managing patients with irritable bowel syndrome

PURPOSE: To address the diagnosis and clinical management of irritable bowel syndrome (IBS) and provide a discussion of the available serotonergic agents. DATA SOURCES: Recent studies examining the pathophysiology of IBS. CONCLUSIONS: Diagnostic testing may be required in the subset of patients with IBS who present with alarm symptoms, or "red flags," suggestive of underlying organic disease. An important role has been suggested for the neurotransmitter serotonin in both gut motility and visceral pain sensitivity. IMPLICATIONS FOR PRACTICE: A diagnosis of IBS is largely based on symptoms; therefore, effective clinician-patient communication and careful attention to details of patient presentation, history, and physical examination are essential.     

Intermittent Preexcitation: Marked Enhancement of Anterograde Conduction in the Atrioventricular Accessory Pathway with Isoproterenol

A 29-year-old man presented with intermittent preexcitation and exertional syncope. Electrophysiological evaluation in the control state demonstrated a single, left posterior free-wall atrioventricular accessory pathway. The anterograde and retrograde effective refractory periods and block cycle lengths were long in the control state. No tachycardias were induced during programmed electrical stimulation. After intravenous administration of isoproterenol, anterograde conduction of the accessory pathway was markedly enhanced (block cycle length shortened 45% to less than 240 ms) and rapid antidromic reciprocating tachycardia (CL = 250 ms) associated with syncope was observed. Following successful surgical dissection of the accessory pathway the patient has been without tachycardia or exertional symptoms. We conclude that, under the influence of exercise or emotion, patients with intermittent preexcitation may be at risk for serious arrhythmias.     

Localization of the ventricular preexcitation site in Wolff-Parkinson-White syndrome with Doppler tissue imaging.

PURPOSE: The objective of this study was to evaluate the ability of Doppler tissue imaging (DTI) to localize the ventricular emergence site of accessory atrioventricular pathways (Wolff-Parkinson-White syndrome). METHODS: Thirty-three patients were studied prospectively by Doppler tissue imaging (128XP and Sequoia 256 echocardiographic systems; Acuson, Mountain View, Calif) before investigation of Wolff-Parkinson-White syndrome and after radiofrequency ablation of the accessory pathways. The normal appearance of the ventricular contractions was defined in a group of 10 control subjects. The preexcitation zone was determined as a zone of maximum acceleration in "DTI acceleration mode" or as a coded contraction zone in "DTI velocity mode," at the time of the delta wave or before the onset of the QRS complex. RESULTS: The earliest ventricular activation site was correctly localized for 12 of the 15 left-sided pathways (8 anterior or anterolateral, 2 lateral or posterolateral, 2 inferior). When wall motion abnormalities were detected in the left ventricle by DTI, the left-sided localization was confirmed by electrophysiologic exploration. For the right-sided pathways, the localization was correct in only 4 of 11 cases (3 posteroseptal and 1 anterolateral). After effective ablation in all patients, the abnormalities corresponding to the electrophysiologic data disappeared totally in only 11 of 16 patients. CONCLUSION: In the presence of Wolff-Parkinson-White syndrome, DTI localizes contraction abnormalities associated with early activation of a part of the ventricle. However, the interpretation of the images remains difficult because the normal coding of the contraction of the ventricular walls depends on the incidence for which they are investigated. This noninvasive examination seems to be an effective tool for localizing the left-sided accessory pathways of the left ventricle, in particular in the anterior, anterolateral, or inferior walls.     

Recognition, diagnosis, and treatment of restless legs syndrome

Purpose: To review the symptoms, diagnosis, and treatment of restless legs syndrome (RLS) and its relevance to nurse practitioners (NPs).
Data sources: Comprehensive review of the scientific literature on the diagnosis and treatment of RLS in adults.
Conclusions: RLS is a chronic neurological disorder that, with varying degrees of severity, affects 5%–10% of the general population. Because of the circadian pattern of onset, the symptoms of RLS may be associated with significant sleep disturbance and may have a negative impact on quality of life. RLS is characterized by a compelling urge to move the legs and usually accompanied or caused by uncomfortable sensations in the legs. Symptoms begin or worsen during periods of rest or inactivity and are worse in the evening or at night. Other features supportive of a diagnosis include a family history, the presence of periodic leg movements in sleep, and the relief of symptoms after treatment with a dopaminergic therapy. Although the etiology of RLS is unknown, it is thought that symptoms result from a central dopaminergic dysfunction and dopamine agonists are considered first-line treatment for moderate-to-severe primary RLS. Nondopaminergic therapies and nonpharmacologic interventions may also be appropriate in the management of less severe cases of RLS.
Implications for practice: NPs are often the first healthcare providers to see patients with RLS and therefore need to be able to accurately recognize and diagnose the disorder; this, in turn, will enable them to successfully manage the treatment of RLS.     

118例SARS患者胸部X线表现分析

目的：总结严重急性呼吸综合征(SARS)的胸部X线表现特点及变化规律。方法：分析118例经临床确诊的SARS患者胸部X线显示肺部病变出现的时间、部位、范围及影像学特点，以及与临床表现的关系。结果：99．2％的患者在病程中胸部X线显示有肺部病变，79．7％的患者在发病后4d内X线胸片显示肺部病变；52．5％的患者为双肺、多肺叶病变；7例死亡病例的肺部病变出现早，而且累及范围广、病情进展快。结论：肺部病变出现越早、范围越广、进展越快，临床症状越重，预后差。     

Brugada综合征和致心律失常型右室心肌病

Brugada综合征和致心律失常型右室心肌病（ARVC）两者临床表现相似,均可导致恶性心律失常和猝死。该文就Brugada综合征和ARVC在临床表现、心电图特征等方面进行了对比分析,并对两者的诊断、鉴别诊断及治疗进行简单介绍。     

B型预激综合征射频消融后心功能变化

目的：比较射频消融前后B型预激综合征心功能变化,方法：根据QRS波时间将46例B型预激综合征患者分为两组,A组27例,QRS波时间0．11－0．13s;B组19例,QRS波时间0．14－0．16s。射频消融前及术后3－5天测左室的心功能。结果,术后A组的每搏量（SV）、射血分数（EF）、峰射血率（PER）、峰充盈率（PFR）及B组的SV、EF均略高于术前（P＞0．05）。尤其B组的PER、PFR明显高于术前（P＜0．05）。结论射频消融后,随着预激成分的消失,心功能可得到一定程度的改善,且术前预激成分越多,QRS流越宽,术后改善越明显。     

代谢综合征合并脑卒中67例分析

目的 探讨代谢综合征（MS）合并脑卒中的临床特点及预后.方法 对经头颅CT或MRI证实的脑卒中合并MS 67例和同期住院脑卒中非MS 105例的临床资料（包括卒中类型、预后、并发症）进行分析比较.结果 脑梗塞MS组92 53%,非MS组85 71%;近期死亡率MS组25.37%,非MS组8.57%;住院期间并发症,MS组肺部感染、呼吸衰竭、心力衰竭、肾功能衰竭机率较非MS组明显升高,脑疝和消化道出血两组差异无显著性.结论 代谢综合征合并脑卒中以脑梗塞多见,住院期间并发症多,近期死亡率高.     

History of Wolff-Parkinson-White syndrome

While Drs. Wolff, Parkinson, and White fully described the syndrome that bears their names in 1930, prior case reports had already described the essentials. Over the ensuing century this syndrome has captivated the interest of anatomists, clinical cardiologists, and cardiac surgeons. Stanley Kent described lateral muscular connections over the atrioventricular (AV) groove, which he felt were the normal AV connections. The normal AV connections were, however, clearly described by His and Tawara. True right-sided AV connections were initially described by Wood et al., while Ohnell first described left free wall pathways. David Scherf is thought to be the first to describe our current understanding of the pathogenesis of the Wolff-Parkinson-White (WPW) syndrome in terms of a reentrant circuit involving both the AV node--His axis as well as the accessory pathway. This hypothesis was not universally accepted and many theories were applied to explain the clinical findings. The basics of our understandings were established by the brilliant work of Pick, Langendorf, and Katz who by using careful deductive analysis of ECGs were able to define the basic pathophysiological processes. Subsequently, Wellens and Durrer applied invasive electrical stimulation to the heart in order to confirm the pathophysiological processes. Sealy and his colleagues at Duke University Medical Center were the first to successfully surgically divide an accessory pathway and ushered in the modern area for curative therapy for these patients. Morady and Scheinman were the first to successfully ablate an accessory pathway (posteroseptal) using high-energy direct-current shocks. Subsequently, Jackman, Kuck, Morady, and a number of groups proved the remarkable safety and efficiency of catheter ablation for pathways in all locations using radiofrequency energy. More recently, Gallob et al. first described the gene responsible for a familial form of WPW. The current ability to cure patients with WPW is due to the splendid contributions of individuals from diverse disciplines from throughout the world.     

Sweet's syndrome associated with systemic inflammatory response syndrome

Septic shock is characterised by infection causing a systemic inflammatory response, end-organ failure and acute circulatory collapse. Treatment consists of antimicrobial therapy and the supportive management of multi-organ failure. We report a case of what we believed to be septic shock due to pyelonephritis in a patient whose condition continued to deteriorate despite conventional treatment until the diagnosis of Sweet's syndrome was made. Once she was started on high dose steroids, her condition improved and she made a full recovery. We believe this to be the first case of a severe systemic inflammatory response syndrome associated with Sweet's syndrome. Received: 20 January 1998 Accepted: 12 June 1998     

Atypical AV nodal reentry with bystander accessory pathway: an unusual mechanism of preexcited tachycardia

We present an unusual mechanism of preexcited tachycardia--atypical AV nodal reentry with bystander AP. It can be differentiated from other preexcited tachycardias by its variable degree of preexcitation (either spontaneous or in response to atrial pacing), higher degree of preexcitation with pacing near the origin of the AP than during tachycardia, inability to preexcite the tachycardia by either late atrial or ventricular premature beats, the presence of nonpreexcited atypical AV nodal reentry tachycardia following successful AP ablation, and by exclusion of atrial tachycardia.     

机械通气合并下呼吸道感染和多器官功能障碍患者的预后因素分析

目的：探讨影响机械通气合并下呼吸道感染和多器官功能障碍综合征（MODS）患者的预后因素,为提高机械通气抢救危重病成功率寻找途径。方法：收集120例接受机械通气治疗患者的临床资料,分析下呼吸道感染及MODS发生率与病死率之间的关系,比较MODS存活组与非存活组患者的基本特征（年龄、急性生理和慢性健康状况评分（APACHEⅡ评分）、是否合并慢性器官功能不全和其它部位感染、机械通气时间等）。结果：120例中有105例（87．5％）并发医院下呼吸道感染,分离出486株细菌,其中G^-杆菌350株（72．0％）,尤以铜绿假单胞菌居多（212株,43．62％）;79例（65．8％）发生MODS,其中48例（60．8％）死亡;未合并感染者死亡2例,单一细菌感染者死亡15例,混合细菌感染者死亡56例（P＜0．005）,且MODS存活组与非存活组患者在年龄,APACHEⅡ评分及机械通气时间3个方面差异有显著性（P＜0．05或P＜0．001）。结论：虽然机械通气治疗是危重病患者抢救中不可缺少的手段,但合并下呼吸道感染和MODS是这类患者病死率高的主要原因,其中感染病原菌种类、数量、年龄、APACHEⅡ评分及机械通气治疗时间可能是不容忽视的因素。     

河北省213例严重急性呼吸综合征临床分析

目的 总结河北省临床诊断为严重急性呼吸综合征(SARS)病例的病情发展规律，探讨其治疗与预后的关系。方法 采用流行病学调查方法，到各定点医院如实采集确诊SARS病例213例，录入计算机，用Access建立《SARS病历摘要表》数据库，以SPSS11．5版统计软件进行数据整理和分析。结果 ①213例中有明显SARS接触者194例(91．1％)，年龄18～59岁者196例，占92．0％；②213例患者均有发热，伴有干咳190例(89．2％)，乏力71例(33．3％)，气短49例(23．0％)；213例患者中有69例(32．4％)白细胞下降，血小板减少者37例(17．4％)，但未见明显出血倾向；胸片表现早期有异常，一般以点片状影、单侧或双侧肺叶的炎性浸润性阴影为主；③213例SARS患者，单纯西医药治疗84例，中西医结合治疗129例；④213例SARS患者中治愈202例，治愈率94．8％；死亡11例，病死率5．2％。结论 SARS有较强的传染性，传播速度快，人群普遍易感，发病有家庭和医院聚集传播的现象，213例SARS治疗效果理想。