Asymptomatic Wolff-Parkinson-White. Should we intervene?

Sudden Cardiac Death: The Most Feared but Potentially Preventable Presentation of Wolff-Parkinson-White Syndrome

Background. Wolff-Parkinson-White syndrome is an uncommon cardiac disorder characterized by the presence of one or more accessory pathways that predispose patients to frequent episodes of arrhythmias. The prognosis is usually good, but there is a lifetime risk of malignant arrhythmias and sudden cardiac death. Case Summary. A 25-year-old male presented a witnessed out-of-hospital cardiac arrest with ventricular fibrillation rhythm. Due to rapid initiation of prehospital advanced life support, return of spontaneous circulation was observed. During the transport to the hospital, an irregular wide complex tachycardia suggestive of preexcited atrial fibrillation with haemodynamic instability was also observed and a synchronized shock was applied. Baseline 12-lead electrocardiogram was compatible with sinus rhythm and ventricular preexcitation pattern. After clinical stabilization, an electrophysiological study was performed confirming the presence of a left anterolateral accessory pathway with a short antegrade effective refractory period. Successful radiofrequency catheter ablation was achieved. Discussion. The reported clinical case recalls fundamental features of the Wolff-Parkinson-White syndrome and outlines the increasing evidence and importance of the invasive risk stratification and even catheter ablation in asymptomatic patients who suffer from this uncommon disease that may have a dramatic and fatal initial clinical manifestation.

Endocavitary electrophysiological study by percutaneous antecubital vein and without X-ray for risk stratification of asymptomatic ventricular pre-excitation in young athletes

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Evaluation of AP is usually performed by transesophageal and intracardiac studies.

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In young athletes with AVP, our standard of care is to perform ESnoXR.

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ESnoXR may considered a less invasive alternative for risk stratification of AP.

Athletes with asymptomatic ventricular pre-excitation (VP) should undergo electrophysiological study for risk stratification. We aimed to evaluate the feasibility, efficacy, safety and tolerability of an electrophysiological study using a percutaneous antecubital vein access and without the use of X-ray (ESnoXr). Methods: We collected data from all young athletes < 18 year-old with AVP, who underwent ESnoXr from January 2000 to September 2020 for evaluation of accessory pathway refractoriness and arrhythmia inducibility using an antecubital percutaneous venous access. Endocavitary signals were used to advance the catheter in the right atrium and ventricle. Results: We included 63 consecutive young athletes (mean age 14.6 ± 1.9 years, 46% male). Feasibility of the ESnoXr technique was 87% while in 13% fluoroscopy and/or a femoral approach were needed. Specifically, fluoroscopy was used in 7 cases to position the catheter inside the heart cavities with an average exposure of 43 ± 38 s while in 2 femoral venous access was needed. The mean procedural time was 35 ± 11 min. The exam was diagnostic in all patients, there were no procedural complications and tolerability was excellent. 53% of the patients had an accessory pathway with high refractoriness and no inducible atrio-ventricular reentry tachycardia: this subgroup was considered eligible to competitive sports and no event was observed during long-term follow-up (13.6 ± 5.2 years) without drug use. The others underwent catheter ablation. Conclusion. ESnoXr has been shown to be a feasible, effective, safe and well-tolerated procedure for the assessment of arrhythmic risk in a population of young athletes with asymptomatic VP.

Sudden Death in the Young: Information for the Primary Care Provider

There are multiple conditions that can make children prone to having a sudden cardiac arrest (SCA) or sudden cardiac death (SCD). Efforts have been made by multiple organizations to screen children for cardiac conditions, but the emphasis has been on screening before athletic competition. This article is an update of the previous American Academy of Pediatrics policy statement of 2012 that addresses prevention of SCA and SCD. This update includes a comprehensive review of conditions that should prompt more attention and cardiology evaluation. The role of the primary care provider is of paramount importance in the evaluation of children, particularly as they enter middle school or junior high. There is discussion about whether screening should find any cardiac condition or just those that are associated with SCA and SCD. This update reviews the 4 main screening questions that are recommended, not just for athletes, but for all children. There is also discussion about how to handle post-SCA and SCD situations as well as discussion about genetic testing. It is the goal of this policy statement update to provide the primary care provider more assistance in how to screen for life-threatening conditions, regardless of athletic status.

Electrocardiographic interpretation in athletes

Participation in regular exercise of moderate intensity is associated with a plethora of systemic benefits, including a reduction in risk factors for coronary atherosclerosis; however, intensive exercise may paradoxically culminate in sudden cardiac arrest among individuals harboring arrhythmogenic substrates. The precise mechanism for arrhythmogenesis is likely multifactorial, however, surges in catecholamines, electrolyte shifts, acid-base disturbances, increased core temperature and demand myocardial ischemia are potential contributors. Although most deaths occur in middle aged and older males with atherosclerotic coronary artery disease, a significant proportion also affect young athletes with inherited or congenital cardiac abnormalities. The impact of such catastrophes on society, particularly when a young high-profile athlete is affected could be considered a justified reason for identifying individuals who may be at risk. Given the rarity of deaths in young athletes, only the simplest screening test, such as the 12-lead electrocardiography (ECG) may be considered to be cost effective. The ECG is effective for detecting serious electrical diseases in young athletes such as congenital electrical accessory pathways and ion channel diseases but can also identify athletes with potential life-threatening structural diseases such as hypertrophic and arrhythmogenic cardiomyopathy. One of the concerns about ECG screening is that regular intensive exercise results in several physiological alterations in cardiac structure and function that are reflected on the athlete's ECG. Sinus bradycardia, first-degree atrioventricular block, incomplete right bundle branch block, minor J-point elevation and large QRS voltages are common. Conversely, some repolarization anomalies affecting the ST segment, T waves and QT interval may overlap with patterns observed in patients with serious cardiac diseases. The situation is complicated further because age, sex and ethnicity of the athletes also influence the ECG and there is a risk that erroneous interpretation could have serious consequences. This review will describe the normal electrical patterns of the "athlete's heart" and provide insights into differentiation physiological electrical patterns from those observed in serious cardiac disease.

Manifest preexcitation with a prolonged PR interval: What is the mechanism?

A 44-year-old woman with a past history of surgical ablation of an accessory pathway presented to our facility with episodes of palpitations and dizziness. An ECG showed sinus rhythm with a prolonged PR interval and a preexcited QRS complex. An EP study revealed AV conduction through a postero-septal accessory pathway and a prolonged PR interval due to severe intra-atrial conduction delay.

Abnormal ECG Findings in Athletes: Clinical Evaluation and Considerations

PURPOSE OF REVIEW

Pre-participation cardiovascular evaluation with electrocardiography is normal practice for most sporting bodies. Awareness about sudden cardiac death in athletes and recognizing how screening can help identify vulnerable athletes have empowered different sporting disciplines to invest in the wellbeing of their athletes.

RECENT FINDINGS

Discerning physiological electrical alterations due to athletic training from those representing cardiac pathology may be challenging. The mode of investigation of affected athletes is dependent on the electrical anomaly and the disease(s) in question. This review will highlight specific pathological ECG patterns that warrant assessment and surveillance, together with an in-depth review of the recommended algorithm for evaluation.

Comparison of Electrophysiologic Profiles in Pediatric Patients with Incidentally Identified Pre-Excitation Compared with Wolff-Parkinson-White Syndrome

The rising utilization of screening electrocardiograms has resulted in increased incidental identification of ventricular pre-excitation in pediatric patients. We compared accessory pathways of incidentally identified pre-excitation to Wolff-Parkinson-White Syndrome (WPW) with the aim to identify factors important in preprocedural counseling and planning. This single-center, retrospective study of patients ≤18 years without congenital heart disease identified 227 patients diagnosed with pre-excitation and referred for invasive electrophysiology study between 2008 and 2017. WPW Syndrome was diagnosed in 178 patients, while 49 patients had incidental identification of pre-excitation. Anterograde conduction of incidentally identified accessory pathways was not clinically different between the two cohorts at baseline or upon isoproterenol infusion. However, the proportion of accessory pathways meeting high-risk criteria was significantly lower than in patients diagnosed with WPW, 12% versus 28% (p < 0.05). Retrograde conduction at baseline of incidentally diagnosed accessory pathways was slower with a median block cycle length 365 milliseconds (IQR 260 to 450) versus 290 milliseconds (IQR 260 to 330, p < 0.01). In the incidentally identified cohort, right-sided, paraHisian, and fascicular pathways were more common with fewer attempted ablations (71% vs 94%, p < 0.001) and lower success rate (91% vs 97%, p < 0.001). A binomial logistic regression analysis further indicated patients incidentally identified with pre-excitation were associated with having lower rates of inducible supraventricular tachycardia, atrial fibrillation, and ablations performed, in addition, to having right-sided pathways. In conclusion, as patients with incidentally identified pre-excitation present more frequently for consideration of invasive electrophysiology study, these results impact procedural approaches, technical considerations, patient counseling, and outcome expectations.

Asymptomatic Ventricular Pre-excitation: Between Sudden Cardiac Death and Catheter Ablation

Debate about the best clinical approach to the management of asymptomatic patients with ventricular pre-excitation and advice on whether or not to invasively stratify and ablate is on-going. Weak evidence about the real risk of sudden cardiac death and the potential benefit of catheter ablation has probably prevented the clarification of action in this not infrequent and sometimes conflicting clinical situation. After analysing all available data, real evidence-based medicine could be the alternative strategy for managing this group of patients. According to recent surveys, most electrophysiologists invasively stratify. Based on all accepted risk factors - younger age, male, associated structural heart disease, posteroseptal localisation, ability of the accessory pathway to conduct anterogradely at short intervals of ≤250 milliseconds and inducibility of sustained atrioventricular re-entrant tachycardia and/or atrial fibrillation - a shared decisionmaking process on catheter ablation is proposed.

Transesophageal and invasive electrophysiologic evaluation in children with Wolff-Parkinson-White pattern

BACKGROUND

Risk stratification for Wolff-Parkinson-White (WPW) pattern either by noninvasive or invasive tests is important to determine whether an ablation is necessary or not. The aim was to compare noninvasive tests and invasive studies in a pediatric WPW population.

METHODS

A total of 71 WPW patients (median age 14 years [interquartile range, 11-16 years]; 43 male) underwent Holter monitoring, exercise stress test (EST), and transesophageal electrophysiological study (TEEPS). In the case of a ≤270-ms effective refractory period of accessory pathway or induction of supraventricular tachycardia using TEEPS, patients were classified as high risk and underwent invasive electrophysiological study (EPS).

RESULTS

Nine of 23 patients with low risk by Holter and eight of 26 patients with low risk by EST had high risk in TEEPS. Risky TEEPS results were detected in 42 of 71 patients and those patients underwent EPS. High-risk characteristic in EPS was detected in seven of nine patients with low risk by Holter and in seven of eight with low risk by EST. Both tests yielded moderate specificity (52-69%) and negative predictive value (61-69%) according to TEEPS.

CONCLUSION

Holter and EST have low predictive value in WPW risk stratification. However, TEEPS and EPS are extremely valuable in WPW risk stratification. TEEPS may reveal important and useful results for WPW risk determination, especially in small children not having undergone EPS in order to avoid its complications.

The Wolf-Parkinson-White ECG Pattern - Assessing the Mortality Risk

The presence of a Wolf-Parkinson-White (WPW) pattern is not uncommonly discovered on a life insurance applicant's ECG. How does one determine the appropriate mortality risk in this population? This article will discuss the risk of sudden cardiac death (SCD), the interpretation of electrophysiology testing results, and risk-stratification both for asymptomatic individuals and those who have had ablation treatment.

Evaluation and management of wolff-Parkinson-white in athletes

CONTEXT

Wolff-Parkinson-White (WPW) is a cardiac conduction system disorder characterized by abnormal accessory conduction pathways between the atria and the ventricles. Symptomatic patients classically present with palpitations, presyncope, or syncope that results from supraventricular tachycardia. While rare, sudden cardiac death may be the first manifestation of underlying disease and occurs more frequently in exercising individuals.

EVIDENCE ACQUISITION

Medline and PubMed databases were evaluated through 2012, with the following keywords: WPW, Wolff-Parkinson-White, pre-excitation, sudden cardiac death, risk stratification, and athletes. Selected articles identified through the primary search, along with relevant references from those articles, were reviewed for pertinent clinical information regarding the identification, evaluation, risk stratification, and management of WPW as they pertained to the care of athletes.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 1.

RESULTS

Diagnosis of WPW is confirmed by characteristic electrocardiogram changes, which include a delta wave, short PR interval, and widened QRS complex. Utilization of the electrocardiogram as part of the preparticipation physical evaluation may allow for early identification of asymptomatic individuals with a WPW pattern. Risk stratification techniques identify individuals at risk for malignant arrhythmias who may be candidates for curative therapy through transcatheter ablation.

CONCLUSION

WPW accounts for at least 1% of sudden death in athletes and has a prevalence of at least 1 to 4.5 per 1000 children and adults. The risk of lethal arrhythmia appears to be higher in asymptomatic children than in adults, and sudden cardiac death is often the sentinel event. The athlete with WPW should be evaluated for symptoms and the presence of intermittent or persistent pre-excitation, which dictates further consultation, treatment, and monitoring strategies as well as return to play.

Aborted sudden cardiac death as first presentation of Wolff-Parkinson-White syndrome

Sudden cardiac death (SCD) can be the first clinical manifestation of Wolff-Parkinson-White (WPW) syndrome. Catheter ablation of accessory pathways is now a safe and effective procedure, and is widely recommended in patients with WPW syndrome. However, management of the asymptomatic WPW patient remains controversial. Recent studies have readdressed the issue of risk stratification and prophylactic catheter ablation. We describe a case of malignant arrhythmia and aborted SCD as first presentation of WPW syndrome in a previously asymptomatic 17-year-old patient.

Asymptomatic Wolff-Parkinson-White Syndrome: Who Should Be Treated?

This article discusses the merits of electrophysiology study (EPS) and/or ablation for asymptomatic preexcitation Wolff-Parkinson-White (WPW) ECG pattern. Sudden deaths in asymptomatic patients are too few to merit broad screening and aggressive intervention. It also discusses the risks of ablation and the low predictive accuracy of EPS. When WPW is an incidental finding, the decision to proceed with investigation and ablation can be made considering patients' situations and preferences. An invasive strategy is targeted at patients concerned about the low risk of life-threatening arrhythmia as a first presentation after a discussion of the risks and benefits.

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.

Adding an electrocardiogram to the pre-participation examination in competitive athletes: a systematic review

No matter how rare, the death of young athletes is a tragedy. Can it be prevented? The European experience suggests that adding the electrocardiogram (ECG) to the standard medical and family history and physical examination can decrease cardiac deaths by 90%. However, there has not been a randomized trial to demonstrate such a reduction. While there are obvious differences between the European and American experiences with athletes including very differing causes of athletic deaths, some would highlight the European emphasis on public welfare vs the protection of personal rights in the USA. Even the authors of this systematic review have differing interpretation of the data: some of us view screening as a hopeless battle against Bayes, while others feel that the ECG can save lives. What we all agree on is that the USA should implement the American Heart Association 12-point screening recommendations and that, before ECG screening is mandated, we need to gather more data and optimize ECG criteria for screening young athletes.

When should we recommend catheter ablation for patients with the Wolff-Parkinson-White syndrome?

PURPOSE OF REVIEW

Catheter ablation has been proven as very effective and safe therapy for patients with symptomatic Wolff-Parkinson-White (WPW) syndrome. Its application in asymptomatic individuals with WPW pattern remains controversial. This review will elaborate on the role of catheter ablation in symptomatic and asymptomatic patients with WPW pattern on ECG.

RECENT FINDINGS

Several recent prospective studies evaluated invasive risk stratification followed by prophylactic catheter ablation in asymptomatic patients with WPW pattern. Inducibility of arrhythmias in these patients during invasive electrophysiological study was shown to predict the development of future symptomatic arrhythmias. Although ablation of accessory pathways performed in 'inducible' patients decreased the incidence of subsequent symptomatic arrhythmias, the studies were not powered to detect a reduction in life-threatening arrhythmias.

SUMMARY

Radiofrequency catheter ablation remains the first-line therapy for patients with symptomatic WPW syndrome. Invasive electrophysiological study and possible ablation of accessory pathway may be offered to well informed asymptomatic individuals with WPW if they are willing to trade the very small risk of subsequent sudden death or incapacity for a small immediate procedural risk of serious complications or death. Asymptomatic patients may require invasive risk stratification and possible catheter ablation for important social or professional reasons.

Electrocardiographic markers of sudden death

The 12-lead ECG has limited utility to predict the risk for sudden cardiac death in common cardiac diseases such as coronary artery disease and idiopathic dilated cardiomyopathy. However, it is quite useful in diagnosing less common cardiac conditions that are associated with an increased risk for sudden death.

The Wolff–Parkinson–White electrocardiogram pattern in athletes: how and when to evaluate the risk for dangerous arrhythmias. The opinion of the paediatric cardiologist

Although diagnostic assessment and treatment have been described in detail in patients with symptomatic Wolff-Parkinson-White (WPW) syndrome, the management of asymptomatic subjects remains controversial. Usually they are assumed to have a benign prognosis, although they do very occasionally present with ventricular fibrillation (VF) as the first manifestation of the syndrome. Discovering a WPW pattern in a previously asymptomatic athlete on a routine electrocardiogram (ECG) identifies the necessity for more accurate screening tests. However, non-invasive methods (Holter monitoring, exercise treadmill testing) seem to be relatively incomplete for risk stratification, especially for athletes. Current guidelines do not always recommend a routine electrophysiological study (EPS) in patients with an asymptomatic WPW ECG pattern, especially in children younger than 12 years. Individuals who engage in high-risk occupations or those patients who have a pre-excitation pattern which precludes them from following their chosen career or activities may be exceptions. The presence of inducible reciprocating tachycardia during EPS, especially when it triggers atrial fibrillation with short RR interval, can represent a specific risk marker of dangerous arrhythmias.

Sudden death in Wolff-Parkinson-White syndrome combined with syncope: a case report

Electrocardiogram showing Wolff-Parkinson-White (WPW) pattern in an asymptomatic patient is common, but it is difficult to assess the potential risk of sudden death in such cases. Although the incidence of sudden death in these patients is extremely low, an interventional approach is suggested for all patients despite its controversial nature. Syncope, despite being induced by various mechanisms, has been considered an alarming sign of sudden death of WPW syndrome. We describe a 16-year-old female patient with an electrocardiogram that demonstrated a WPW pattern combined with unexplained syncope. None of the examinations, including biochemical profiles, brain computed tomography, transthoracic echocardiography, head-up tilt table test and exercise electrocardiogram, clarified her syncope. Consequently, no further electrophysiologic study was performed for this patient. Unfortunately, the patient suffered sudden death while running. The case highlights the need for vigilance when unexplained syncope combined with WPW syndrome. Such cases have high risk of sudden death, and thus, further interventional study and treatment is indicated.

Electrophysiological evaluation of asymptomatic ventricular pre-excitation in children and adolescents

BACKGROUND

Diagnostic assessment and treatment have been described in detail in symptomatic WPW syndrome, but little information exists about significance and prognosis of an incidentally found ventricular pre-excitation (VPE) in asymptomatic children. The aim of the study was to evaluate, retrospectively, the role of electrophysiological study (EPS) in the assessment of the arrhythmic risk in asymptomatic patients with VPE.

MATERIAL AND METHODS

Sixty-two asymptomatic children and adolescents (38 M/24 F, aged 9.8+/-5.1 years) referred to our Division between 1996 and 2002 for an incidentally found VPE underwent an EPS for arrhythmic risk stratification. The following parameters were examined: anterograde effective refractory period of the accessory pathway (AP), the 1-to-1 conduction over the AP, the inducibility of atrio-ventricular re-entrant tachycardia (AVRT) and the inducibility of atrial fibrillation (AF) with measurement of minimal RR between two consecutive preexcitated QRS complexes, the average RR interval of all cycles, and the percentage of preexcitated QRS complexes.

RESULT

During the EPS, 36 patients (58.1%) experienced sustained SVT. The tachycardia was initiated in the basal state in 22 patients and after isoproterenol in the other 14. Orthodromic AVRT (cycle length 305.9+/-48.5 ms) was recorded in 29 patients. In three patients, both orthodromic and antidromic AVRT were recorded, with different cycle length (CL). Antidromic AVRT alone (CL 239.5+/-13.7 ms) was recorded in four patients. AF was recorded in nine patients: in six patients, it was recorded after the induction of orthodromic or antidromic AVRT, in the other three cases AF was the first and only arrhythmic event. The minimal RR between two consecutive pre-excitated QRS ranged between 250-230 ms (mean 237.5+/-9.6 ms). In the 26 patients who presented no induced sustained tachycardia in the EPS, the 1:1 conduction over the AP ranged between 210 and 600 ms (mean 279.6+/-75.2 ms).

CONCLUSIONS

Electrophysiological evaluation remains the gold standard for assessing risk of life-threatening arrhythmias in patients with VPE. However, a high proportion of healthy children and adolescents with VPE can experience sustained AVRT and/or AF during EPS. These results raise questions about the necessity of an aggressive treatment approach to prevent those "rare" cases of sudden death.

Brugada syndrome and "Brugada sign": clinical spectrum with a guide for the clinician

BACKGROUND

Patients with the manifest Brugada syndrome have an inordinate risk of sudden death and are candidates for implantation of a defibrillator. The Brugada type electrocardiogram (ECG) abnormality (the "Brugada sign"), however, is known to be associated with a wide range of conditions, many of which may not pose such a threat. Clinicians need guidance in choosing a rational approach for the evaluation and treatment of patients with a finding of the Brugada sign.

METHODS

A systematic literature search was performed to identify publications on the Brugada syndrome and the Brugada-type ECG abnormality, with special emphasis on analyzing outcomes data. In addition, the ECG database of our institution was reviewed for tracings consistent with the Brugada sign, and, when possible, clinical correlations were made.

RESULTS

Patients with the Brugada sign and a family history of sudden death or a personal history of syncope are at a high risk of sudden death and therefore should be strongly considered for implantation of a defibrillator. In patients who are hospitalized and critically ill, the Brugada sign is frequently the result of severe hyperkalemia, drug toxicity, or right ventricular injury. In most individuals with no symptoms and without a family history of sudden death, the Brugada sign is likely a normal variant.

CONCLUSIONS

Most patients with the Brugada sign can be risk-stratified with simple clinical tools. Specific testing for the Brugada syndrome should be reserved for questionable cases and for the research setting. A provisional diagnostic-therapeutic algorithm is offered as a means of assisting the clinician in the evaluation and treatment of patients with the Brugada sign.

The natural history of Wolff-Parkinson-White syndrome in 228 military aviators: a long-term follow-up of 22 years

BACKGROUND

Wolff-Parkinson-White (WPW) syndrome poses a risk for tachyarrhythmias and sudden cardiac death. Most WPW studies have relatively limited numbers of subjects and brief follow-up periods.

METHODS

We reviewed records of 238 consecutive military aviators with WPW syndrome evaluated from 1955 to 1999. Follow-up was by questionnaires, telephone interviews, or death certificates. Events included sudden cardiac death and supraventricular tachycardia (SVT) (by electrocardiographic [ECG] documentation or suggestive symptoms).

RESULTS

The mean age was 34.3 years (range 17-56 years). Forty-two (42/238, 17.6%) had SVT (WPW syndrome) and 196 of 238 (82.4%) had the WPW ECG pattern only. The mean follow-up of 21.8 years (range 2-41 years) was obtained on 228 of 238 (96%) for a total of 4906 patient-years. Sudden cardiac death occurred in 1 of 228, an incidence of 0.0002 per patient-year (95% confidence interval 0.0-0.001). SVT occurred in 47 of 228 (20.6%) or 0.01 per patient-year. One hundred eighty-seven (187/228, 82%) initially had the WPW ECG pattern only; 28 of 187 (15.0%) reported SVT during follow-up. Forty-one (41/228, 18%) initially had WPW syndrome; 19 of 41(46.3%) reported additional SVT during follow-up.

CONCLUSION

Sudden cardiac death risk was low (0.02%/patient-year) in this WPW population. The SVT incidence was 1% per patient-year. Referral bias and some characteristics of the unique military aviator population may partly account for these low event rates. However, these results may be more applicable to unselected populations than are tertiary referral-based studies.

Evaluation and treatment of other arrhythmic causes of syncope in children and adolescents with an apparently normal heart: Wolff-Parkinson-White syndrome and right ventricular cardiomyopathy

Syncope could be a symptom of tachyarrhythmias related to the Wolff-Parkinson-White syndrome, or the consequence of the ventricular tachycardias seen in patients with Arrhythmogenic Right Ventricular Cardiomyopathy. Syncope should be considered the consequence of atrial fibrillation or flutter, with rapid conduction over the accessory atrioventricular connection in Wolff-Parkinson-White syndrome, and these patients are at risk of presenting with ventricular fibrillation and sudden death. Radiofrequency ablation of the anomalous, accessory connection, which can be performed with high success and low complication rates, should be the first line of treatment for symptomatic children and adolescents with Wolff-Parkinson-White. Arrhythmogenic Right Ventricular Cardiomyopathy is a rare disorder of the cardiac muscle affecting predominantly, although not exclusively, the right ventricle. Clinical presentation varies from asymptomatic cases to patients with severe symptoms related to life-threatening arrhythmias, right ventricular failure, or congestive heart failure with involvement of both ventricles. The clinical diagnosis is difficult. A set of major and minor criteria has been proposed to help to identify patients with this disease. Without an identified cause, the treatment of patients with Arrhythmogenic Right Ventricular Cardiomyopathy is symptomatic. Medical management of the associated congestive heart failure, pharmacologic treatment of the arrhythmias, radiofrequency ablation and implantable cardioverter-defibrillator therapy should all be considered.

Should patients with asymptomatic wolff-parkinson-white pattern undergo a catheter ablation?

Many individuals with the Wolff-Parkinson-White electrocardiographic pattern are asymptomatic. Optimal management of these individuals is still a matter of debate. On the one hand, sudden cardiac death from ventricular fibrillation is a rare yet possible outcome in these individuals. On the other hand, there is a low risk of serious complication from electrophysiologic study and ablation. Given that the risk of these competing strategies is comparable, the decision needs to be individualized with considerable patient input.

Ventricular pre-excitation in the general population: a study on the mode of presentation and clinical course

OBJECTIVE

To describe the mode of presentation and the clinical course of patients with ventricular pre-excitation (Wolff-Parkinson-White (WPW) syndrome), with special emphasis on asymptomatic cases in the general population.

METHODS

Over an eight year period (1990-97) a prospective population based survey of cases with WPW pattern was conducted in a defined population in north west Greece (340 000 inhabitants). ECGs with WPW pattern were obtained from a widespread pool of ECGs within the health system.

RESULTS

During the study period, 157 cases with WPW pattern were identified (49 female, 108 male). Ages ranged from infants to 84 years, mean (SD) 49.1 (21.0) years in female and 39.6 (20.6) years in male subjects (p < 0.01); 78 (49%) had no history of syndrome related symptoms. Asymptomatic subjects (n = 77; 24 female, 53 male) were older than symptomatic subjects (mean age 46.7 (21.0) v 38.5 (20.6) years, p < 0.03). Documented supraventricular tachycardia was recorded in 27 patients (17%) and atrial fibrillation in 12 (8%) (mean age at first episode 31.2 (18.3) and 51.6 (20.7) years, respectively, p < 0.01). During follow up (mean 55 months) no case of sudden death occurred. Three asymptomatic subjects reported episodes of brief palpitation.

CONCLUSIONS

WPW pattern is more common, and diagnosed at a younger age, in men than in women. About half the patients with WPW pattern on ECG are asymptomatic at diagnosis and tend to remain so thereafter. No sudden cardiac death occurred during the study period.

Clinical features of Wolff-Parkinson-White syndrome

Wolff-Parkinson-White syndrome is the most common form of ventricular preexcitation. Understanding this syndrome is fundamental for anyone interested in learning about arrhythmias. This review addresses (1) the historic sequence of events that led to the understanding of this syndrome; (2) the pathologic, embryologic, and electrophysiologic properties of accessory pathways; (3) the epidemiology and genetics of this syndrome; (4) the clinical diagnosis of this syndrome, with special emphasis on the arrhythmias that patients with ventricular preexcitation are predisposed to; and (5) the therapy for patients with Wolff-Parkinson-White syndrome.

Management of the child with Wolff-Parkinson-White syndrome and supraventricular tachycardia: model for cost effectiveness

In the next decade, "better" management will be defined by cost effectiveness including morbidity, mortality, and cost. We used a cost-effectiveness model for children with Wolff-Parkinson-White syndrome (WPW) and supraventricular tachycardia (SVT) comparing medical, surgical, and catheter ablative treatment between age 5 years (estimated average age at first recurrence after infancy) and age 21. Charges were quantitated from actual hospital bills; mortality was estimated from the literature; morbidity was assessed by estimating the number of hours in SVT, hours in clinic, hours in routine hospital bed, and hours in hospital intensive care; and the hours were then multiplied by a severity factor, normalized to 1.0 for 1 hour of SVT (0.5 for 1 hour in clinic, 0.75 for routine hospital, and 2.0 for intensive care). Overall charges (5 to 21 years old) for catheter ablation ($17,236) were 39% of surgical management and 57% of medical management; estimated mortality for catheter ablation (5 to 21 years old including failures that reverted to medical management) was 0.15%, which was 10% of medical management and 28% of surgical management; morbidity for catheter ablation was 27.6 units, which was 32% of medical management and 36% of surgical management. Sensitivity analysis demonstrated that the catheter ablation strategy remained preferable throughout the range of plausible values of cost, mortality, and morbidity (including a repeat procedure for initial failures). Therefore, catheter ablation has lower cost, mortality, and morbidity than either medical management or surgery and is the treatment of choice for the child 5 years of age or older with WPW and SVT. This type of analysis can be used for other forms of chronic disease in children.

Indications for radiofrequency ablation in the pediatric population

Pediatric radiofrequency ablation procedures have become commonplace since their introduction to clinical practice 6 years ago. Excellent success rates coupled with low complication rates have allowed these procedures to be offered as first-line therapy to many children. This review focuses on the current indications for radiofrequency ablation in children. These indications are not the same as for adults. They are based on the natural history of various forms of arrhythmias, the risks of the procedure, and the current success rates of the procedures, all of which are dependent upon the age of the patient.

Driving issues related to arrhythmic syncope

The safety of driving in patients with cardiac arrhythmias is a common concern. Although the risk of driving in these patients cannot be reduced to zero, available data and expert consensus suggest that most patients with arrhythmias can return to driving with a relatively low risk of harm to themselves and others, that is, a risk within the limits deemed acceptable by society. Specific recommendations for allowing patients with various cardiac rhythm abnormalities to drive are reviewed in detail.

Reproducibility of transesophageal pacing in patients with Wolff-Parkinson-White syndrome

The purpose of this study was to assess, in patients with ventricular preexcitation, the time dependent physiological variation of antegrade conduction properties in the AV node and in accessory pathways (Aps) as a function of autonomic tone variation induced by posture and physical effort, using noninvasive transesophageal atrial pacing. In 74 WPW patients (mean age 21.31 +/- 9.46 yrs), AV node and Kent antegrade effective refractory periods (at pacing cycle lengths 600, 400, and 320 ms), Wenckebach point, shortest preexcited RR intervals during sustained atrial fibrillation (AF) or atrial pacing, as well as the inducibility of AV reentry tachycardia (AVRT) and AF/flutter (AFL) were assessed. All measurements were carried out at rest, in supine and upright positions, and during effort. A second study was carried out approximately 3 months after the first study. The coefficient of variation (CVs) and reproducibility (CRs) were calculated. For each parameter, the differences between the mean of the two studies were not statistically significant. The CVs and CRs ranged between 0.4% and 4% and between 2 and 28 ms, respectively. AF was induced in 40 (54%) of 74 patients at the first study and in 30 (40.5%) of 74 patients at the second study. AVRT was induced in 33 (45%) of 74 patients at the first study and in 38 (51.3%) of 74 patients at the second study. The reproducibility was 45% for AF/AFL and 65% for reentry tachycardia. Transesophageal atrial pacing is a reliable method for noninvasive reproducible evaluation of antegrade electrophysiological properties of both the AV node and APs in WPW patients. However, the effect of autonomic balance variation has to be taken into account and precisely defined because it may significantly affect the inducibility of supraventricular arrhythmias and the estimation of the absolute values of the vulnerable parameters.

Curative Therapy for Supraventricular Arrhythmia with Radiofrequency Catheter Ablation—Comparison with Surgical Therapy

Radiofrequency catheter ablation is a newly introduced technique that does not require open heart surgery and is designed for curing patients with arrhythmia. We present our experience with this technique in 223 patients, with recurrent supraventricular tachycardia due to accessory pathways associated with the Wolff-Parkinson-White syndrome or AV nodal reentrant tachycardia. Of the patients, 119 underwent radiofrequency ablation of accessory pathways, while 101 underwent AV nodal modification. Two patients underwent both AV nodal modification and accessory pathway ablation during the same session. One patient had AV nodal ablation. Mean age was 39.4 ± 14.1 years (13–73 years). There were 108 males and 115 females. Except for 1 patient, all had significant symptoms. Radiofrequency ablation performed during the first session was successful in 215 patients (96.4%). With repeat ablation, 218 (97.8%) of the patients were successfully ablated. When compared with surgery, the efficacy is similar; however, radiofrequency ablation is less costly and results in less morbidity. Radiofrequency catheter ablation is highly efficacious and is the treatment of choice in patients who are at risk for sudden death or have failed drug therapy. It should also be offered as an alternative to lifelong drug therapy.

Should radiofrequency current ablation be performed in asymptomatic patients with the Wolff-Parkinson-White syndrome?

The exiting new method of ablation of accessory pathways using radiofrequency current applied by catheters will dramatically change our therapeutic decisions in these patients in the near future. This brief survey reviews the existing literature about the risk of the disease as well as of the procedure of catheter ablation. From these data, the risk of sudden death appears to be extremely low in asymptomatic Wolff-Parkinson-White (WPW) individuals. Side effects of catheter ablation may result from the invasive procedure as well as from radiation exposure (the latter to the patient as well as to operating physicians). While the complication rate in experienced centers is extremely low, a multicenter registry of the success and complication rate is urgently needed in view of the many centers starting with catheter ablation. Based on a subjective benefit-to-risk analysis, asymptomatic WPW individuals should be offered catheter ablation only under special circumstances (high risk profession, athletes, family history of sudden death). On the other hand, catheter ablation need not be and should not be considered generally in asymptomatic individuals with WPW pattern. Finally, this author cannot imagine that the energy, time, and money spent for mass screening and eventual catheter ablation of asymptomatic WPW individuals with its attending risks can be outweighed by the potential benefits for these asymptomatic individuals.