A case of Williams syndrome with Wolff-Parkinson-White syndrome.

INTRODUCTION: Williams syndrome (WS) cases have been reported to have with 25-100 times greater increased risk of sudden cardiac death (SCD). SCD has been reported in cases without any evidence of structural cardiovascular anomalies. Wolff-Parkinson-White (WPW) syndrome is characterized by short PR interval and delta wave. Ventricular preexcitations can develop paroxysmal reentrant tachycardia through Kent bundle or less frequent atrial fibrillation and in some cases with accessory pathway effective refractory period (APERP) under 250 ms considered as risky and may lead to SCD. WS associated with WPW has not been reported before. CASE REPORT: An 11-year-old male who had been followed up with WS was referred to pediatric cardiology outpatient clinic with the complaint of palpitation. Electrocardiographic examination showed short PR interval and delta wave in the ECG consistent with WPW. He underwent electrophysiological study (EPS). Basic measurements were performed, and APERP was found at 280 ms cycle atrial pacing. RF energy was delivered using a 4 mm tip nonirrigated radiofrequency (RF) ablation catheter where the best ventriculoatrial (VA) signals were received and the AP was abolished within few seconds. DISCUSSION AND CONCLUSIONS: Although, WPW cases are usually asymptomatic or related to SVT, the risk of SCD should not be ignored. Thus, all patients with WPW deserve an EPS for assessing the AP conduction properties. Due to the increased risk of SCD in patients with WS compared to general population, in the presence of concomitant WPW, these patients should be evaluated with EPS even if they do not have symptoms.

EPM algorithm: A stepwise approach to accessory pathway localization in ventricular pre-excitation.

BACKGROUND: Accurate estimation of accessory pathway (AP) localization in patients with ventricular pre-excitation or Wolff-Parkinson-White (WPW) syndrome remains a diagnostic challenge. Existing algorithms have contributed significantly to this area, but alternative algorithms can offer additional perspectives and approaches to AP localization. OBJECTIVE: This study introduces and evaluates the diagnostic accuracy of the EPM algorithm in AP localization, comparing it with established algorithms Arruda and EASY. METHODS: A retrospective analysis was conducted on 138 patients from Hospital São Paulo who underwent catheter ablation. Three blinded examiners assessed the EPM algorithm's diagnostic accuracy against the Arruda and EASY algorithms. The gold standard for comparison was the radioscopic position of the AP where radiofrequency ablation led to pre-excitation disappearance on the ECG. RESULTS: EPM showed a diagnostic accuracy of 51.45%, closely aligning with Arruda (53.29%) and EASY (44.69%). Adjacency accuracy for EPM was 70.67%, with Arruda at 66.18% and EASY at 72.22%. Sensitivity for EPM in distinguishing left vs. right APs was 95.73%, with a specificity of 74.33%. For identifying septal vs. lateral right APs, EPM sensitivity was 82.79% with a specificity of 46.15%. These measures were comparable to those of Arruda and EASY. Inter-observer variability was excellent for EPM, with Kappa statistics over 0.9. CONCLUSION: The EPM algorithm emerges as a reliable tool for AP localization, offering a systematic approach beneficial for therapeutic decision-making in electrophysiology. Its comparable diagnostic accuracy and excellent inter-observer variability underscore its potential clinical applicability. Future research may further validate its efficacy in a broader clinical setting.

Comparison of the Limb-lead Electrocardiogram to the 12-Lead Electrocardiogram for Identifying Conditions Associated with Sudden Cardiac Death in Youth Athletes.

The optimal screening strategy to prevent sudden cardiac death (SCD) in athletes remains unknown. Pre-participation screening with electrocardiogram (ECG) remains controversial. The utility and accuracy of limb-lead (LL) ECG alone in identifying cardiac abnormalities associated with SCD has not been studied. This study was a comparative secondary data analysis, comparing the interpretation accuracy of 4 physicians evaluating publicly available ECGs of the most common cardiac conditions associated with SCD in athletes. Each physician interpreted a total of 100 ECGs: 50 normal ECGs (25 LL and 25 standard 12L) and 50 abnormal ECGs (25 LL and 25 standard 12L). The agreement between LL ECGs and 12L ECGs was assessed by Cohen's kappa coefficient and the accuracy of identifying an abnormal ECG was compared across LL and 12L ECGs using a chi-squared test. Inter-rater reliability was assessed by estimating the Fleiss's kappa coefficient. The sensitivity of LL ECG and 12L ECG was identical at 86%. The specificity of LL ECG was 75% (95% CI = 65% to 83%) and 12L ECG was 82% (95% CI = 73% to 89%). Substantial agreement was seen between LL ECG and 12L ECG interpretation across all readers (k = 0.63; 95% CI = 0.49 to 0.77). Interpretation accuracy was 81% (95% CI = 74% to 86%) and 84% (95% CI 78% to 89%) using LL ECG and 12L ECG, respectively (p = 0.43). In conclusion, the accuracy, sensitivity, and specificity were high and comparable for both LL ECG and 12L ECG in identifying cardiovascular conditions associated with SCD. Agreement between LL ECG and 12L ECG was substantial.

The use of intravenous amiodarone in patients with atrial fibrillation and Wolff-Parkinson-White syndrome.

BACKGROUND: It was reported that intravenous amiodarone might induce ventricular fibrillation for acute treatment in patients with atrial fibrillation (AF) and Wolff-Parkinson-White (WPW) syndrome. No study was done to assess its application comprehensively in this population. METHODS: This study was a retrospective analysis and undertaken by reviewing medical records and electronic databases to search for patients admitted with tachycardia resulting from WPW syndrome and AF, who have intravenously administrated amiodarone at the emergency department from January 2008 to June 2018. RESULTS: Thirty patients were involved in this study, of which 27 were males. The mean age of the patients was 47.8 ± 17.0 years. The mean systolic blood pressure and diastolic blood pressure were 111.9 ± 18.3 mmHg and 76.1 ± 14.6 mmHg, respectively. The mean heart rate was 171 (150-189) beats per minute. Half of the patients (53.3%) had no comorbidities, and only one had prior syncope. Nearly 17 patients (56.7%) started with a loading dose of 150 mg. No ventricular acceleration or VF developed. The incidence of hypotension was 3.3% (1/30). Eighteen patients (60.0%) restored to sinus rhythm by amiodarone with the conversion time of 486.0 (229.0-1278.0) minutes. CONCLUSIONS: Intravenous amiodarone might be an alternative for acute treatment of AF and WPW syndrome in patients characterized by stable hemodynamics, relatively low admission heart rate, few comorbidities, elder age, and no prior syncope. The loading dosage of 150 mg appeared to be preferred, and the maintenance period was better to less than 12 hours. Monitoring and electrolyte correction were also necessary. It is essential to keep a defibrillator nearby during pharmacologic cardioversion.

Change of Paradigm in the Management of Patients with Accessory Pathways over the Last Forty Years: Wolff-Parkinson-White Syndrome as an Electrophysiological Marvel at Risk of Extinction.

Over the last decades, the approach to the Wolff-Parkinson-White syndrome, as well as its treatment, has substantially changed, leading to improvement in the prognosis and quality of life of these patients. From the first diagnostic electrophysiologic studies to the most recent evaluations, important data on pathophysiologic and clinical aspects have been gathered, and this learning journey is still not concluded. This body of knowledge is a fundamental part of any cardiologists' armamentarium despite the fact that this syndrome is rarely observed in adult patients.

Accessory Pathway-Mediated Tachycardias: Precision Electrocardiology Through Standard and Advanced Electrocardiogram Recording Techniques.

An accessory pathway (AP) can be apparent during sinus rhythm if it depolarizes part of the ventricles ahead of the normal wave front from the conduction system. An AP can generate an anatomic circuit able to sustain a macroreentrant atrioventricular reentrant tachycardia. This arrhythmia can engage the normal conducting system in an antegrade direction or retrogradely, generating, respectively, a narrow or a wide complex tachycardia. The combined use of a standard electrocardiogram and an esophageal recording-pacing can be particularly useful in the first approach to patients with Wolff-Parkinson-White syndrome, further stratifying patients requiring electrophysiology study and transcatheter ablation.

Algorithms to Identify Accessory Pathways' Location on the 12-Lead Electrocardiogram.

The ability to estimate accessory pathway (AP) position enables pre-procedural planning, reduces mapping times, and improves risk estimates as part of the patient consent process. In this article, the nomenclature and important concepts of AP localization algorithms are outlined. An overview of three prominent algorithms is then provided. Each represents an era of invasive treatment of APs: surgical therapy, endocardial ablation, and contemporary electroanatomic mapping. In this manner, the premises, pitfalls, and evolution of AP localization algorithms are illustrated. In addition, the pertinent features of their work are distilled in a simplified topographic algorithm with the interventional electrophysiologist in mind.

Sudden Cardiac Death in Patients with Ventricular Preexcitation.

Patients with the Wolff-Parkinson-White syndrome may experience benign and malignant arrhythmias, the most common being atrioventricular reentrant tachycardias. This arrhythmia may degenerate into atrial fibrillation, which can be conducted over an accessory pathway capable of exceptionally fast conduction to the ventricles and degenerate into ventricular fibrillation, leading to sudden cardiac death. These life-threatening events generally affect symptomatic patients in their third or fourth decade. Although rare, ventricular fibrillation may be the first clinical manifestation in subjects who are asymptomatic or unaware of their conditions. Electrophysiologic study may be useful to identify subjects at high risk of sudden cardiac death.

Methodology of Typical Accessory Pathway Catheter Ablation.

Accessory pathways are abnormal electrical conductions between the atrial and ventricular myocardium, bypassing the atrioventricular node and as such are an important substrate for arrhythmias. Ablation is a curative treatment and should always be offered to symptomatic patients and asymptomatic patients with high risk professions. Adequate knowledge and understanding of different mapping and ablation techniques is pivotal to achieve successful outcomes.

Effect of pulmonary vein isolation on atrial fibrillation recurrence after accessory pathway ablation in patients with Wolff-Parkinson-White syndrome.

BACKGROUND: Although successful ablation of the accessory pathway (AP) eliminates atrial fibrillation (AF) in some of patients with Wolff-Parkinson-White (WPW) syndrome and paroxysmal AF, in other patients it can recur. HYPOTHESIS: Whether adding pulmonary vein isolation (PVI) after successful AP ablation effectively prevents AF recurrence in patients with WPW syndrome is unknown. METHODS: We retrospectively studied 160 patients (102 men, 58 women; mean age, 46 ± 14 years) with WPW syndrome and paroxysmal AF who underwent AP ablation, namely 103 (64.4%) undergoing only AP ablation (AP group) and 57 (35.6%) undergoing AP ablation plus PVI (AP + PVI group). Advanced interatrial block (IAB) was defined as a P-wave duration of >120 ms and biphasic (±) morphology in the inferior leads, using 12-lead electrocardiography (ECG). RESULTS: During the mean follow-up period of 30.9 ± 9.2 months (range, 3-36 months), 22 patients (13.8%) developed AF recurrence. The recurrence rate did not differ in patients in the AP + PVI group and AP group (15.5% vs 10.5%, respectively; P = .373). Univariable and multivariable Cox regression analyses showed that PVI was not associated with the risk of AF recurrence (hazard ratio, 0.66; 95% confidence interval, 0.26-1.68; P = .380). In WPW patients with advanced IAB, the recurrence rate was lower in patients in the AP + PVI group vs the AP group (90% vs 33.3%, respectively; P = .032). CONCLUSIONS: PVI after successful AP ablation significantly reduced the AF recurrence rate in WPW patients with advanced IAB. Screening of a resting 12-lead ECG immediately after AP ablation helps identify patients in whom PVI is beneficial.

Radiofrequency catheter ablation without radiation exposure in a 13th week pregnant woman with Wolff-Parkinson-White syndrome.

A 36-year-old woman with 12-week gestation visited the emergency department, complaining of palpitations. Her electrocardiography (ECG) demonstrated ventricular pre-excitation combined with atrial fibrillation. The polarity of the delta waves in leads V5, V6, I, and aVL were positive and negative in leads V1, III, and aVF, suggesting that the accessory pathway (AP) was located on the right posterior free wall. She did not want to take any medicine to prevent the tachycardia. Moreover, the shortest pre-excited RR interval during the atrial fibrillation was 200 ms, so we decided to ablate the AP without fluoroscopy. An electrophysiology study was performed with guidance of a 3-dimension (3D) navigation system and intracardiac echocardiography (ICE). We ablated the right free wall AP without fluoroscopy. A follow-up ECG no longer exhibited any delta waves. Even in the early period of pregnancy, catheter ablation might be performed safely using ICE and a 3D navigation system without fluoroscopy. Therefore, it could more often be considered as a therapeutic option in pregnant women without concern for radiation exposure.

New algorithm for accessory pathway localization focused on screening septal pathways in pediatric patients with Wolff-Parkinson-White syndrome.

BACKGROUND: Published algorithms for accessory pathway localization in Wolff-Parkinson-White (WPW) syndrome are inaccurate in pediatric patients, especially for septal pathways. OBJECTIVE: We aimed to develop a new algorithm that is sensitive for septal pathways and more applicable in pediatric patients. METHODS: In 120 patients (mean age: 11.7 ± 3.9 years) who underwent catheter ablation for WPW syndrome, the candidate criteria for new algorithm were searched by comparing electrocardiography parameters and accessory pathway locations. A new algorithm was designed to increase the sensitivity for septal pathways. For validation, 142 patients (mean age: 15.8 ± 3.7 years) were additionally evaluated. New and published algorithms were applied to electrocardiography of 262 patients and the results were compared. RESULTS: The new algorithm achieved its best discrimination by combining several parameters together in each step: (1) QRS polarity in V1 and QRS shape in lead I for left/right discrimination, and (2) delta wave polarity in V1, QRS transition in precordial leads, and delta wave polarity in lead III for septal pathway screening. The new algorithm showed higher sensitivity for septal pathways (95.7%) than 7 published algorithms (average: 62.1%), with satisfactory positive predictive value (77.9%). Delta wave polarity in V1 among septal pathways and QRS axis among right anteroseptal pathway showed age-related trend; this could be the reason for the lower accuracy in localizing septal pathways in children. CONCLUSION: The inaccuracy of published algorithms in pediatric patients is due to the age-related trend in the electrocardiography of septal pathways. The new algorithm was superior for localizing septal pathways in pediatric patients.

Novel Assessment of Accessory Pathway Function in Patients with Wolff-Parkinson-White Syndrome.

Surrogates for the shortest pre-excited R-R interval in atrial fibrillation (SPERRI) such as the accessory pathway effective refractory period (APERP) and shortest pre-excited paced cycle length (SPPCL) are flawed assessments of accessory pathway function in patients with WPW. Multi-extrastimulus pacing may have the theoretical advantage of more accurately mimicking the clinical reality of atrial fibrillation and thus may serve to better assess accessory pathway function. This cross-sectional study included 25 consecutive patients, aged ≤ 18 years, undergoing electrophysiology study for WPW. The longest S1S2, S2S3, S3S4 coupling intervals at which the antegrade AP refractoriness occurred, SPERRI, and SPPCL were recorded. Induction of atrial fibrillation was attempted in all patients and induced in 8 (32%, 4 SPERRIbaseline (265 ms ± 61 ms), 4 SPERRIIsuprel (258 ms ± 41 ms)). At baseline, the lower value of the S3ERP or S4ERP (274 ms ± 52 ms) was lower than the SPPCL (296 ms ± 54 ms, p < 0.0001) and APERP (296 ms ± 41 ms, p < 0.0001). More patients had S3ERP or S4ERP ≤ 250 ms (12/25, 48%) compared to those with APERP ≤ 250 ms (2/25 8%), p = 0.0016), SPPCL 5/24, 20%), p = 0.008 or either (6/25, 24%), p = 0.0143). With Isuprel, the lower value of the S3ERP or S4ERP (221 ms ± 36 ms) trended to be lower than the APERP (252 ms ± 36 ms, p = 0.0001) and the SPPCL (266 ms ± 57 ms, p = 0.001). With Isuprel, there was no statistical difference in the proportion of patients with S3ERP or S4ERP < 250 ms (12/16, 75%) compared to those with APERP ≤ 250 ms ((9/16, 56%), p = 0.08), SPPCL ≤ 250 ms ((9/16, 56%), p = 0.08), or either ((10/16, 63%), p = 0.16). Multi-extrastimulus pacing protocols demonstrate that accessory pathways are less refractory than as defined by single extrastimulus pacing and straight decremental pacing.

Review paper on WPW and athletes: Let sleeping dogs lie?

Accessory pathways are present in 1 in 300 young individuals. They are often asymptomatic and potentially lethal arrhythmias may be the first presentation. During long-term follow-up, up to 20% of asymptomatic individuals with pre-excitation go on to develop an arrhythmia and the absence of traditional clinical and electrophysiological high-risk markers does not guarantee the "safe" nature of an accessory pathway. The widespread availability of permanent cure for the condition at low risk by catheter ablation, creates an incentive to screen for accessory pathways with a 12-lead ECG, particularly in individuals who are perceived to be at increased risk, such as athletes and high-risk professions. We review the existing literature on the assessment and management of accessory pathways (Wolff-Parkinson-White [WPW] syndrome) and discuss its implications for the young athletic population.

Loss of ventricular preexcitation during noninvasive testing does not exclude high-risk accessory pathways: A multicenter study of WPW in children.

BACKGROUND: Abrupt loss of ventricular preexcitation on noninvasive evaluation, or nonpersistent preexcitation, in Wolff-Parkinson-White syndrome (WPW) is thought to indicate a low risk of life-threatening events. OBJECTIVE: The purpose of this study was to compare accessory pathway (AP) characteristics and occurrences of sudden cardiac arrest (SCA) and rapidly conducted preexcited atrial fibrillation (RC-AF) in patients with nonpersistent and persistent preexcitation. METHODS: Patients 21 years or younger with WPW and invasive electrophysiology study (EPS) data, SCA, or RC-AF were identified from multicenter databases. Nonpersistent preexcitation was defined as absence/sudden loss of preexcitation on electrocardiogram, Holter monitoring, or exercise stress test. RC-AF was defined as clinical preexcited atrial fibrillation with shortest preexcited R-R interval (SPERRI) ≤ 250 ms. AP effective refractory period (APERP), SPERRI at EPS , and shortest preexcited paced cycle length (SPPCL) were collected. High-risk APs were defined as APERP, SPERRI, or SPPCL ≤ 250 ms. RESULTS: Of 1589 patients, 244 (15%) had nonpersistent preexcitation and 1345 (85%) had persistent preexcitation. There were no differences in sex (58% vs 60% male; P=.49) or age (13.3±3.6 years vs 13.1±3.9 years; P=.43) between groups. Although APERP (344±76 ms vs 312±61 ms; P<.001) and SPPCL (394±123 ms vs 317±82 ms; P<.001) were longer in nonpersistent vs persistent preexcitation, there was no difference in SPERRI at EPS (331±71 ms vs 316±73 ms; P=.15). Nonpersistent preexcitation was associated with fewer high-risk APs (13% vs 23%; P<.001) than persistent preexcitation. Of 61 patients with SCA or RC-AF, 6 (10%) had nonpersistent preexcitation (3 SCA, 3 RC-AF). CONCLUSION: Nonpersistent preexcitation was associated with fewer high-risk APs, though it did not exclude the risk of SCA or RC-AF in children with WPW.

Intra-cardiac ultrasound guided approach for catheter ablation of typical right free wall accessory pathways.

BACKGROUND: Right free wall accessory pathways (AP) are difficult to treat with catheter ablation as ablation catheter (AC) instability at the tricuspid annulus often precludes successful procedure. The aim of our study was to test a novel intra-cardiac echocardiography (ICE) guided technique for AC placement. Feasibility and success rates were observed. METHODS: Eight consecutive patients (aged 29 ± 21 years, 4 female) with Wolff-Parkinson-White syndrome and a right free wall AP were included in the study. ICE, three-dimensional (3D) electro-anatomic mapping (EAM) system, and a steerable long sheath were used together with either an irrigated or a non-irrigated tip radio-frequency AC to achieve a "loop" manoeuvre which provided AC tip stability at the ventricular aspect of the tricuspid annulus. X-ray fluoroscopy was not used. RESULTS: Three patients had an anterior and five had a lateral location of the right free wall AP. Procedures were successful in all patients, without recurrences during the mean follow-up of 397 ± 363 days. Average procedural duration was 90 ± 31 min. On average, 6.6 ± 5.7 ablations were needed. Average time to terminate AP conduction after the start of ablation was 4.8 ± 4.2 s. In five patients (62%) AP conduction was successfully terminated with the first ablation. There were no procedural complications. CONCLUSIONS: The novel ICE-guided approach with concomitant use of the steerable sheath and the 3D EAM system for zero-fluoroscopy mapping and ablation of the right free wall APs proved feasible and resulted in excellent acute and long-term outcomes.