Effects of Isoflurane on Electrophysiological Measurements in Children with the Wolff-Parkinson-White Syndrome

This study was designed to assess the effects of isoflurane (ISO) on the electrophysiological properties of the accessory pathway, atrium, ventricle, and AV node in children with the Wolff-Parkinson-White (WPW) syndrome. The results of programmed electrical stimulation were analyzed in 51 patients (4 months to 17 years of age) with WPW. The study population was divided into two groups. Twenty-seven patients received local anesthesia and intramuscular injection of meperidine, promethazine, and chlorpromazine (MPC group). Twenty-four patients received general anesthesia with ISO inhalation (ISO group). We compared the antegrade effective refractory period of the accessory pathway (antegrade APERP), ventricular effective refractory period (VERP), atrial effective refractory period (AERP), AH interval, and cycle length of circus movement tachycardia (CMT-CL) in 12 pairs of age and sex matched patients selected from the MPC and ISO groups. Of the 12 pairs of age and sex matched patients, antegrade APERP in patients who received ISO (299 ± 17 ms, mean ± SEM) was significantly longer as compared with matched patients in the MPC group (262 ± 5 ms, P < 0.025). The VERP and AERP in patients from the ISO group were significantly prolonged compared with the MPC patients (239 ± 7 vs 210 ± 8 ms, P < 0.025, and 228 ± 11 vs 180 ± 6 ms, P < 0.01, respectively). There was no significant difference in the AH interval or CMT-CL between the two subgroups. Thus, ISO prolongs the antegrade APERPs as well as the effective refractory periods of atrial and ventricular muscle in children with WPW, while the AH interval and CMT-CL appear to be unaffected. Care must be taken in interpreting measurements of the antegrade APERP made in patients under general anesthesia for RF ablation of accessory pathways.     

Localization of the Accessory Pathway in the Wolff-Parkinson-White Syndrome from the Ventriculo-Atrial Conduction Time of Right Ventricular Apical Extrasystoles

In 18 consecutive patients with the Wolff-Parkinson-White syndrome undergoing electrophysiologic study, the ventriculo-atrial conduction time of right ventricular apical extrasystoles which advanced atrial activation during circus movement tachycardia was studied in relation to accessory pathway location. Accessory pathway location was determined by delta wave morphology during maximal pre-excitation, mapping of alrial activation during circus movement tachycardia and ventricular pacing, the effect of bundle branch block on ventriculo-atrial conduction time during circus movement tachycardia, and the effect of pacing from different sites in the atria on the stimulus-to-delta wave interval. In 7 patients with septal accessory pathways, ventriculo-atrial conduction time was similar during circus movement tachycardia and following right ventricular apical extrasystoles (mean difference 0 ± 6 ms, range -5 to + 10 ms). In contrast, in 11 patients with a left free wall accessory pathway, ventriculo-atrial conduction time increased by 46 ± 15 ms (range 15 to 65 ms) following right ventricular apical exlrasystoles. Therefore, measurement of the ventriculo-atrial conduction time of right ventricular extrasystoles during circus movement tachycardia provides an easy way to distinguish between septal and left free wall accessory pathways. This finding may be of particular use in determining the location of concealed bypass tracts.     

Electrophysiologic Evaluation of Asymptomatic Patients with the Wolff-Parkinson-White Pattern

In the past 4 years, 34 asymptomatic patients with the Wolff-Parkinson-White (WPW) pattern underwent electrophysiologic study. The effective refractory period (ERP) of antegrade conduction over the accessory pathway was 288 +/- 29 msec. In three asymptomatic patients (9%), the antegrade ERP of the accessory pathway was shorter than 250 msec. The antegrade ERP of the accessory pathway became shorter than 250 msec in an additional 12 of 22 (55%) patients after isoproterenol administration. Nineteen (56%) of the asymptomatic patients showed the absence of retrograde conduction over the accessory pathway even after isoproterenol administration. The rate of induction of orthodromic reciprocating tachycardia in the asymptomatic WPW patients was 15% (5/34), which was significantly lower than that in the symptomatic patients. These data suggest that in the asymptomatic patients, the absence of retrograde conduction over the accessory pathway is the reason they remained asymptomatic, free of reciprocating tachycardia. However, even in the asymptomatic patients, some had the accessory pathway in which antegrade ERP was shorter than 250 msec. They may result in rapid ventricular conduction over the accessory pathway when atrial fibrillation develops.     

Electrophysiologic characteristics and radiofrequency catheter ablation in children with Wolff-Parkinson-White syndrome

BACKGROUND: The majority of cardiac arrhythmias in children are supraventricular tachycardia, which is mainly related to an accessory pathway (AP)-mediated reentry mechanism. The investigation for Wolff-Parkinson-White (WPW) syndrome in adults is numerous, but there is only limited information for children. This study was designed to evaluate the specific electrophysiologic characteristics and the outcome of radiofrequency (RF) catheter ablation in children with WPW syndrome. METHODS: From December 1989 to August 2005, a total of 142 children and 1,219 adults with atrioventricular reentrant tachycardia (AVRT) who underwent ablation at our institution were included. We compared the clinical and electrophysiologic characteristics between children and adults with WPW syndrome. RESULTS: The incidence of intermittent WPW syndrome was higher in children (7% vs 3%, P=0.025). There was a higher occurrence of rapid atrial pacing needed to induce tachycardia in children (67% vs 53%, P=0.02). However, atrial fibrillation (AF) occurred more commonly in adult patients (28% vs 16%, P=0.003). The pediatric patients had a higher incidence of multiple pathways (5% vs 1%, P<0.001).Both the onset and duration of symptoms were significantly shorter in the pediatric patients. The antegrade 1:1 AP conduction pacing cycle length (CL) and antegrade AP effective refractory period (ERP) in children were much shorter than those in adults with manifest WPW syndrome. Furthermore, the retrograde 1:1 AP conduction pacing CL and retrograde AP ERP in children were also shorter than those in adults. The antegrade 1:1 atrioventricular (AV) node conduction pacing CL, AV nodal ERP, and the CL of the tachycardia were all shorter in the pediatric patients. CONCLUSION: This study demonstrated the difference in the electrophysiologic characteristics of APs and the AV node between pediatric and adult patients. RF catheter ablation was a safe and effective method to manage children with WPW syndrome.     

Nonclinical Ventricular Tachycardia in the WolflF-Parkinson-White Syndrome

Between September 1980 and June 1984 we assessed the specificity of induction of ventricular tachycardia (VT) with one or two ventricular extrastimuli in a consecutive series of 148 patients undergoing electrophysiological assessment for the Wolff-Parkinson-White (WPW) syndrome by standard electrophysiological techniques. Fifteen patients (10%) had six or more beats of VT induced by one ventricular extrastimulus after a ventricular drive (9 patients), two ventricular extrastimuli during reciprocating tachycardia (6 patients), and during a single atrial extrastimulus (1 patient). None of the six men and nine women, aged 16-61 years, had apparent heart disease. VT lasted for 20 +/- 14 (mean +/- standard deviation) cycles with a cycle length of 235 ms +/- 27 and was generally polymorphic. One patient had ventricular fibrillation. These patients were compared to 15 age- and sex-matched patients studied in the same time period. There was no difference in anterograde effective refractory period of the accessory pathway (316 +/- 92 vs 319 +/- 68 ms), ventricular effective refractory period (218 +/- 12 vs 227 +/- 23), shortest pacing cycle length maintaining 1:1 anterograde conduction over the accessory pathway (306 +/- 132 vs 320 +/- 67) or minimum R-R interval between preexcited beats during atrial fibrillation (280 +/- 68 vs 294 +/- 105). All patients are alive and well over a follow-up interval of 20 +/- 11 months on no antiarrhythmic therapy (13 patients) or on propranolol (2 patients).(ABSTRACT TRUNCATED AT 250 WORDS)     

Latent Sinoatrial Conduction Disturbances in Symptomatic Patients with Wolff-Parkinson-White Syndrome

Sinoatrial conduction abnormalities were studied in fourteen patients with Wolff-Parkinson-White (WPW) syndrome and frequent attacks of supraventricular paroxysmal tachycardia. Sinoatrial conduction time (SACT), obtained by the method of constant atrial pacing, was prolonged in all but two patients. The mean value was 277 ± 56 ms (mean ± SD). SACT was measured in the same way in sixteen patients without signs of pre-excitation or Sinoatrial disease; SACT was significantly shorter (p < 0.001) than in the WPW group of patients. The prolongation of SACT in patients with WPW syndrome was confirmed by measuring SACT by the alternative method of programmed atrial stimulation. SACT was found to be prolonged in eight patients (mean ± SD = 239 ± 47 ms). Whether our results should be attributed to WPW syndrome or frequent supraventricular tachycardias—both being a characteristic feature of our patients—remains uncertain. The results of this study, however, indicate that in symptomatic patients with WPW syndrome and frequent episodes of supraventricular tachycardia, Sinoatrial conduction is frequently impaired. Slackening of the sinoatrial conduction is a possible predisposing factor for initiation of tachycardias in the WPW syndrome.     

Wide Complex Tachycardia Due to Automaticity in an Accessory Pathway

Patients with the Wolff-Parkinson-White (WPW) syndrome have preexcited tachycardia as the result of atrial arrhythmias or antidromic reentry. This article describes a patient with persistent wide complex tachycardia due to abnormal automaticity in the accessory pathway. Radiofrequency catheter ablation resulted in simultaneous elimination of accessory pathway conduction and automaticity. Accessory pathway automaticity may be an infrequent cause of preexcited tachycardia in patients with the WPW syndrome.     

起源于冠状静脉窦口的右侧旁路合并房室结双径路的诊断与鉴别

目的探讨复杂多径路心动过速时的应用拖带和程序S2刺激进行诊断和鉴别分析。 方法回顾性分析1例间歇性预激波患者频发室上性心动过速,经心脏电生理检查行右心室拖带刺激和心室程序S2刺激,测量最后一跳刺激信号到自身心房波间期减去心动过速下心室到心房的间期(SA-VA)和起搏后间期(PPI)－心动过速周长(TCC),并行常规射频导管消融术治疗。 结果术中心室分级刺激S1S1：350 ms诱发右侧旁路参与的房室折返性心动过速,TCL为372 ms, PPI为395 ms,继续行心房S1S2：500/310 ms刺激,"跳跃"诱发同前一样的室房波不融合心动过速。再次行心房S1S1：280 ms刺激,可反复诱发慢快型房室结折返性心动过速。在旁路参与的心动过速下给予心室程序S2刺激,测量PPI为385.1 ms, TCL为360.1 ms,PPI－TCL≤20 ms,证实为右侧旁路参与的房室折返性心动过速,同时存在慢快型房室结折返性行心动过速,给予常规射频导管消融成功径路和旁路。术后随访12个月未有心动过速发作。 结论通过右心室心室拖带刺激,以及测量SA-VA间期和PPI-TCL间期可以用来鉴别典型房室结折返性心动过速与间隔房室旁路。     

Adenosine Induced Ventricular Fibrillation in Wolff-Parkinson-White Syndrome

GUPTA, A. K., et al. : Adenosine Induced Ventricular Fibrillation in Wolff-Parkinson-White Syndrome. VF was observed in four patients (group A) with preexcited AF presenting to the emergency department who had been given 12 mg of adenosine. These patients were resuscitated and underwent electrophysiological study and catheter ablation of the accessory pathway (AP). In a control (group B) of five patients with manifest AP, sustained AF was induced by rapid atrial pacing during electrophysiological study and 12 mg of adenosine was administered. The ECG and electrophysiologic features in the two groups were compared. All patients had a single manifest AP. In group A, three patients had a left free-wall AP and one patient had a posteroseptal AP, while in the control group all had left free-wall APs. The antegrade AP effective refractory period (ERP) in groups A and B was  227 ± 29 and 289 ± 37 ms  , respectively (  P < 0.05  ). The atrial ERP was  210 ± 17 versus 219 ± 21 ms  , respectively, in groups A and B (  P > 0.05  ). The shortest R-R interval during AF in group A was  246 ± 51 ms and 301 ± 60 ms  in group B (  P value < 0.05  ). After adenosine, no patient in group B developed VF. Adenosine may cause VF when administered during preexcited AF. This phenomenon is seen in patients having APs with short refractory periods.     

Unusual Electrocardiographic Findings Associated with Type A Wolff-Parkinson-White Syndrome

A 50-year-old woman with Wolff-Parkinson-White (WPW) syndrome presented with unusual electrocardiographic (ECG) findings following the termination of paroxysmal supraventricular tachycardia. The ECG showed three different QRS complexes and irregular R-R intervals. These QRS complexes consisted of: (1) narrow QRS; (2) wide QRS with delta wave; and (3) wide QRS with left bundle branch block (LBBB). The mechanisms of these findings, revealed by electrophysiological study, were: (1) intermittent anterograde left-sided accessory pathway conduction; (2) rate-dependent ipsilateral LBBB; and (3) intermittent retrogradely conducted atrial echoes that occurred due to intraventricular conduction delay resulting from LBBR. Cases of WPW syndrome with these unusual ECG findings, which were clearly interpreted by electrophysiological study, are rare.     

Mechanism of Double Ventricular Response to a Single Atrial Extrastimulus in Patients with Wolff-Parkinson-White Syndrome

The purpose of this study is to elucidate electrophysiological determinants of double ventricular response (DVR) to a single atrial extrastimulus in Wolff-Parkinson-White (WPW) syndrome. DVR was observed in 5 (3.4%) out of 146 consecutive patients with WPW syndrome. The site of accessory pathway was located in left lateral free wall in four patients and posterior septum in one. DVR was induced by extrastimulus from coronary sinus in four patients with left-sided accessory pathway, and from both coronary sinus and high right atrium in a patient with septal accessory pathway. However, it was not possible to induce DVR from high right atrium in patients with left-sided accessory pathway, because 50 to 80 ms are needed for intra-atrial conduction from high right atrium to coronary sinus. Critical prolongation of normal AV conduction allowing DVR was seen in the slow pathway of AV node in four patients. In the remaining patients requisite conduction delay occurred in both AV node and His-Purkinje system. Single right ventricular extrastimulus could easily elicit orthodromic AV reciprocating tachycardia or echo beat in four out of five patients and incremental ventricular stimulation induced it in the remaining patient, indicating the presence of retrograde block in the normal AV pathway. As requisites of DVR to a single atrial extrastimulus in WPW syndrome: (1) slow antegrade conduction and retrograde block in the normal AV pathway; and (2) stimulation site in the vicinity of accessory pathway, are needed.     

Linking: A Mechanism of Intermittent Preexcitation in the Wolff-Parkinson-White Syndrome

MIDDLEKAUFF, H.R., ET AL.: Linking: A Mechanism of Intermittent Preexcitation in the Wolff-Parkinson-White Syndrome. Intermittent preexcitation in the Wolff-Parkinson-White syndrome has been equated with a long accessory pathway refractory period and long R-R interval between preexcited beats in atrial fibrillation and therefore a low risk for sudden death. A case of Wolff-Parkinson-White syndrome in which preexcitation became intermittent following procainamide infusion, with only moderate prolongation of the accessory pathway refractory period but marked prolongation of the shortest preexcited R-R interval in atrial fibrillation, is described. Programmed ventricular and atrial stimulation demonstrated that intermittent preexcitation was caused by concealed conduction producing a linking phenomenon, facilitated by the antiarrhythmic drug. Linking due to concealed retrograde penetration of a propagated impulse into the accessory pathway may contribute to the disparity between accessory pathway refractory period and shortest preexcited R-R interval in atrial fibrillation in some patients and may be a confounding factor in the interpretation of noninvasive tests of accessory pathway conduction.     

Radiofrequency Catheter Ablation of an Accessory Pathway in a Young Man with Dextroversion

We report an observation of a radiofrequency catheter ablation of an accessory pathway (AP) in a patient with Wolff-Parkinson-White syndrome (WPW) and dextroversion. Atrioventricular rings were mapped by the ablation catheter to locate the shortest local atrioventricular conduction time in sinus rhythm and ventriculoatrial conduction time during orthodromic tachycardia or ventricular pacing. Successful ablation confirmed a right posteroseptal AP localization. Thus, the electrocardiographic modifications due to an AP in this location in the presence of dextroversion were defined.     

Atrial Fibrillation in Wolff-Parkinson-White Syndrome: Reversal of Isoproterenol Effects by Sotalol

Sotalol has Class II and III antiarrhythmic effects. Its efficacy and safety as a treatment of atrial fibrillation in patients with the Wolff-Parkinson-White (WPW) syndrome is controversial. We evaluated the effects of isoproterenol and IV sotalol (1.5 mg/kg in 10 minutes) given together versus isoproterenol alone on anterograde conduction through the AV node and accessory pathway. Atrial fibrillation was induced in 22 patients with WPW (13 men, 9 women, 36 ± 16 years old). AV node and accessory pathway conduction were both enhanced by isoproterenol, although the effect was greater on the AV node. The minimum interval between preexcited QRS complexes shortened in all patients. Conversely, sotalol caused a significant prolongation of the shortest preexcited QRS interval as well as of the shortest interval between narrow QRS complexes. In addition, sotalol reversed all the effects of isoproterenol during atrial fibrillation. The percent of preexcited QRS complexes was not significantly modified because variations in ventricular preexcitation results from a balance between the relative effects on refractoriness of the accessory pathway versus of the AV node and in the amount of respective anterograde and- retrograde concealed conduction. There were no serious adverse effects.'Reversion to sinus rhythm was documented in 12 patients (60%). These short-term observations suggest that sotalol may be safe and effective in the treatment of patients with WPW and atrial fibrillation.     

Risk factors for atrioventricular tachycardia degenerating to atrial flutter/fibrillation in the young with Wolff-Parkinson-White

Background: Atrioventricular reciprocating tachycardia (AVRT) is common in patients (pts) with Wolff‐Parkinson‐White (WPW) syndrome but atrial flutter/fibrillation (AF) with rapid ventricular response (RVR) is rare. Although AF occurs in 18% of adult WPW pts, its incidence in children is unknown. We sought to determine risk factors for AVRT spontaneously degenerating to AF during electrophysiologic studies (EPS) in children with WPW. Methods: This was a retrospective study of children with WPW referred for accessory pathway (AP) ablation without clinical AF. Standard electrophysiologic protocols were performed to induce AVRT. To determine if AF degeneration was associated with patient characteristics, 2‐sample t‐tests, Chi‐square, and Fisher's exact were used. Results: There were 53 (31 males) WPW pts studied. During EPS, AVRT degenerated to AF in 27/53 (51%). RVR was seen in 18/27 (67%) patients. The ventricular cycle length (CL) during AF was shorter with RVR (211 + 24 ms) than without (313 + 65 ms) (P = 0.01). AF occurred more commonly among patients with right anterior AP (P = 0.05). Patient gender, age, height, weight, body surface area, persistence of preexcitation on exercise testing, baseline CL, AVRT conduction, and AP number were not significant AF determinants. The AVRT CL was significantly shorter in patients with (265.2 + 41.5 ms) versus those without (308 + 59 ms) AF (P = 0.01). Preliminary data suggest that AP location may be related to patient ethnicity. Conclusion: AF with RVR occurred following AVRT induction during EPS in 34% of our WPW patients, typically associated with right‐sided AP locations. Time intervals for RVR to degenerate into ventricular fibrillation and lead to SCD are yet to be determined.     

Electrograms for Identification of the Atrial Ablation Site During Catheter Ablation of Accessory Pathways

Background: Catheter ablation of accessory pathways using radiofrequency current has been shown to be effective in patients with Wolff-Parkinson-White syndrome, by using either the ventricular or atrial approach. However, the unipolar electrogram criteria for identifying a successful ablation at the atrial site are not well established. Methods and Results: One hundred patients with Wolff-Parkinson-White were treated by delivering radiofrequency energy at the atrial site. Attempts were considered successful when ablation (disappearance of the delta wave) occurred in < 10 seconds. In eight patients with concealed pathway, the accessory pathway location was obtained by measuring the shortest V-A interval either during ventricular pacing or spontaneous or induced reciprocating tachycardia. In 92 patients both atrioventricular valve annuli were mapped during sinus rhythm, in order to identify the accessory pathway (K) potential before starting the ablation procedure. When a stable filtered (30–250 Hz) “unipolar” electrogram was recorded, the following time intervals were measured: (1) from the onset of the atrial to the onset of the K potential (A-K); (2) from the onset of the delta wave to the onset of the K potential (delta-K); and (3) from the onset of the K potential to the onset of the ventricular deflection (K- V). During unsuccessful versus successful attempts, A-K (51 ± 11 ms vs 28 ± 8 ms, P < 0.0001 for left pathways [LPs]; and 44 ± 8 ms vs 31 ± 8 ms, P < 0.02 for right pathways [RPs]) and delta-K intervals (2 ± 9 ms vs -18 ± 10 ms, P < 0.0001 for LPs; and 13 ± 7 ms vs 5 ± 8 ms, P < 0.02 ms for RPs) were significantly longer. Conclusions: Short A-K interval (< 40 ms), and a negative delta-K interval recorded from the catheter positioned in the atrium are strong predictors of successful ablation of LPs and RPs. Therefore, the identification of the K potential appears to be of paramount importance for positioning of the ablation catheter, followed by analysis of A-K and delta-K unipolar electrogram intervals. However, it appears that the mere recording of K potential is not, per se, predictive of successful outcome, but rather the A-K and delta-K interval.     

Electrophysiological Demonstration of Anterograde Concealed Conduction in Accessory Atrioventricular Pathways Capable Only of Retrograde Conduction

Anterograde concealed conduction into the concealed accessory atrioventricular (AV) pathway has been postulated to be one of the factors preventing the reciprocating process via the accessory pathway in patients with the concealed Wolff-Parkinson-White(WPW) syndrome but its presence has not been documented. To demonstrate the occurrence of anterograde concealment, 12 patients with the concealed WPW syndrome were selected for study. A pacing protocol was designed in which the retrograde conduction of the ventricular extrastimulus over the accessory pathway was assessed during ventricular pacing aione (conventional method) and during the AV simultaneous pacing (simultaneous method); the results were then compared. When the high right atrium was simultaneously paced, the effective refractory period of the concealed accessory pathway shortened as compared with the conventional method in five of 12 patients (from 341.7 ± 110.8 to 312.5 ± 108.2 msec, n = 12), whereas, it decreased in all patients studied when the coronary sinus near the accessory pathway was simultaneously paced (from 375.7 ± 135.0 to 287. ± 116.1 msec, n = 7). These results demonstrate that the AV simultaneous pacing frequently shortens the refractoriness of the concealed accessory AV pathway and such facilitation seems to he well explained by the probable anterograde concealment in it and peeling back of the refractory barrier.     

Ebstein anomaly in an adult presenting with wide QRS tachycardia: diagnostic and therapeutic dilemmas

A 51-year-old man presented to the emergency department with sustained hemodynamically unstable wide QRS tachycardia and was revived successfully by immediate direct current (DC) cardioversion. There was evidence of previous open heart surgery, possibly atrial septal defect closure. Transthoracic echocardiography showed severe Ebstein anomaly with severe tricuspid regurgitation, no residual atrial septal defect, but with severe right ventricular dysfunction. Subsequent electrocardiograms showed transient atrial fibrillation with no manifest Wolff-Parkinson-White (WPW) accessory pathway during sinus rhythm. The cause of wide QRS tachycardia in this patient may be WPW related or ventricular tachycardia. This case illustrates the diagnostic and therapeutic dilemmas in patients with wide QRS tachycardia and suspected WPW syndrome. In addition, this case demonstrates that unoperated Ebstein anomaly can present in late adult life with tachyarrhythmias.     

Transesophageal evaluation of asymptomatic Wolff-Parkinson-White syndrome

Background: Risk stratification for Wolff‐Parkinson‐White (WPW) by intracardiac electrophysiology study (ICEPS) carries risks related to catheterization. We describe an alternative approach by using transesophageal electrophysiology study (TEEPS). Methods: The pediatric electrophysiology database was reviewed for patients with WPW and no documented clinical supraventricular tachycardia (SVT) who underwent risk stratification by TEEPS from October 2005 to November 2010. Of those who underwent subsequent ICEPS, only those with data available to compare accessory pathway (AP) conduction during ICEPS and TEEPS were included. Results: Of 65 patients who underwent TEEPS, 42 were found to have an indication for ablation. The most common indication for ICEPS was inducible SVT, which was induced in 67% of patients. Of 42 patients who underwent subsequent ICEPS, 23 had sufficient data for comparison of AP conduction between ICEPS and TEEPS. There was no difference between the baseline minimum 1:1 antegrade conduction through the accessory pathway found at TEEPS versus ICEPS (312 ± 51 ms vs 316 ± 66 ms, P = 0.5). There was no significant difference between the baseline antegrade AP‐effective refractory period found at TEEPS versus ICEPS (308 ± 34 ms vs 297 ± 37 ms, P = 0.07). There were no complications related to TEEPS or ICEPS. Conclusion: TEEPS is a safe and feasible alternative to ICEPS for risk stratification in patients with asymptomatic WPW and should be considered before ICEPS and ablation. (PACE 2012; 1–5)     

Wolff-Parkinson-White syndrome: essentials for the primary care nurse practitioner

PURPOSE: To provide nurse practitioners with a basic understanding of the pathophysiology, clinical characteristics, diagnostic methods, and management of Wolff-Parkinson-White (WPW) syndrome. DATA SOURCES: Selected research and clinical articles. CONCLUSIONS: WPW syndrome is the most common form of ventricular preexcitation. The ventricular myocardium is activated earlier than expected by an accessory conduction pathway that allows a direct electrical connection between the atria and ventricles. Although many patients remain asymptomatic throughout their lives, approximately half of the patients with WPW syndrome experience symptoms secondary to tachyarrhythmias, such as paroxysmal supraventricular tachycardia, atrial fibrillation, atrial flutter, and, rarely, ventricular fibrillation and sudden death. Symptoms include palpitations, dizziness, syncope, and dyspnea. Diagnosis is usually made by electrocardiogram findings, but further testing may be warranted to confirm the diagnosis. IMPLICATIONS FOR PRACTICE: A thorough patient history and physical examination can aid the practitioner in identifying patients who may have WPW syndrome. With appropriate referral, treatment, and patient education, patients with WPW syndrome can expect to have a normal life expectancy and good quality of life.