[Historical developments in the diagnosis and treatment of pre-excitation syndromes (WPW)]

In 1930, Wolff, Parkinson and White described the syndrome that bears their names. The mechanisms of supraventricular tachycardias were analyzed by brilliant electrocardiography interpretation by Pick and Langendorf. Wellens and Durrer using electrophysiologic studies analyzed the tachycardia mechanism invasively. In Germany the group by Seipel and Breithardt as well as Neuss and Schlepper studied the tachycardia mechanisms and response to antiarrhythmic drugs invasively by electrophysiological studies. Following the first successful interruption of an accessory pathway by Sealy in 1967, surgeons and electrophysiologists cooperated in Germany. Two centers, Hannover and Düsseldorf were established. Direct current (DC) ablation of accessory pathways was introduced by Morady and Scheinman. Because of side effects induced by barotrauma of DC, alternative strategies were studied. In 1987, radiofrequency ablation was introduced and thereafter established as curative therapy of accessory pathways in all locations.

Intermittent Wolff-Parkinson-White Syndrome Mimicking a Ventricular Tachycardia

This case report describes a patient in their 50s with a history of pneumoconiosis and chronic obstructive pulmonary disease who presented to the emergency department with sudden onset shortness of breath.

Risk assessment in patients with symptomatic and asymptomatic pre-excitation

AIMS

Controversy remains as to whether the exercise stress test (EST) is sufficient for risk evaluation in patients with pre-excitation. This study aims to clarify the usefulness of EST in risk stratification in both asymptomatic and symptomatic patients presenting with pre-excitation.

METHODS AND RESULTS

This prospective study includes consecutive asymptomatic and symptomatic patients with pre-excitation referred for risk assessment. All participants performed an incremental EST (bicycle) prior to an electrophysiology study (EPS). Primary data from the EST included loss of pre-excitation during exercise, and primary data from the EPS included the measurement of accessory pathway effective refractory period (APERP), shortest pre-excited RR interval (SPERRI), and inducible arrhythmia with the use of a beta-adrenergic receptor agonist if deemed necessary. One hundred and sixty-four patients (59 asymptomatic, 105 symptomatic) completed an EST and EPS. Forty-five patients (27%) demonstrated low-risk findings on EST, of which 19 were asymptomatic and 26 were symptomatic. Six patients with low-risk EST findings had SPERRI/APERP ≤ 250 ms at EPS, and two of them were asymptomatic. The sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of low-risk EST for excluding patients with SPERRI/APERP ≤ 250 ms were 40, 91, 87, 51, and 60%, respectively. The number of patients with inducible arrhythmia at EPS was similar in the asymptomatic (36, 69%) and symptomatic (73, 61%) groups.

CONCLUSION

Sudden loss of pre-excitation during EST has a low NPV in excluding high-risk APs. The EPS with the use of isoproterenol should be considered to accurately assess the risk of patients with pre-excitation regardless of symptoms (ClinicalTrials.gov Identifier: NCT03301935).

Asymptomatic children with ventricular pre-excitation/WPW pattern

Paediatric patients with ventricular pre-excitation/asymptomatic WPW syndrome have a higher risk of atrial fibrillation degenerating into ventricular fibrillation and sudden cardiac death (SCD). In more than half of these patients this can be the first symptom presenting. Hence, it is important to conduct a risk stratification for SCD in asymptomatic patients with pre-excitation/delta wave in the ECGs. In this review, invasive risk stratification by electrophysiologic testing and ablation is recommended when possible. Catheter ablation is reported to have a high rate of success and low risk of complications.

Cardiovascular Screening before Sports Participation: Results of 11487 Children

AIM

In this study, it is aimed to analyze the data of children who were referred to our clinic for pre-participation sports screening.

METHODS

Data, between September 2017 and December 2021, had been analyzed. All these subjects had been questioned for their personal and family medical stories and examined for cardiovascular system findings. Electrocardiography (ECG) and echocardiography were applied to all of them.

RESULTS

11487 children were consulted to the cardiology clinic for pre-sports participation screening. The mean age was 12.7±4,57 (7-18 years). 34/11487(0,29%) subjects weren't allowed to participate in sports activities at first. In 23 of 34 subjects, cardiac arrhythmias were established. 15 had Wolff-Parkinson-White (WPW) syndrome, 3 subjects had ventricular extrasystole, and also ventricular tachycardia in one of them. Four subjects had long QT syndrome and one had ST elevation with the pre-diagnosis of coronary artery disease. ECG screening alone aided in identifying asymptomatic (0.05%) that could have been potentially at risk for sudden cardiac death.

CONCLUSION

Positive ECG and echocardiography findings involve a very little ratio.But ECG involves an important tool for screening lethal cardiac arrhythmias in asymptomatic patients.If ECG or echocardiography couldn't be taken, further evaluation should be necessary with symptoms and/or family history.

A Subtle ECG Change Leading to Wolff-Parkinson-White Diagnosis Under General Anesthesia: A Case Report

Wolff-Parkinson-White (WPW) syndrome is a congenital cardiac preexcitation syndrome that presents with an uninhibited electrical conduction between the atria and ventricles via an accessory pathway that has the potential for life-threatening arrhythmias. This is a case report of an asymptomatic/undiagnosed 43-year-old female with an incidental finding of WPW pattern during hardware removal surgery of the right hip while under general anesthesia. The identification of asymptomatic patients can be difficult because there may be only subtle changes on the electrocardiogram but could still pose as life-threatening in the presence of supraventricular tachycardia. Because of the potential risks, recommendations were given to follow up with the cardiology department to establish an accurate diagnosis. After recognition, the perioperative anesthetic goal was to prepare for any potential arrhythmia, minimize triggers, and provide proper follow-up so that appropriate testing could be conducted to properly diagnose and manage WPW.

Antidromic and orthodromic reciprocating tachycardias over a novel left-sided accessory pathway involving the vein of Marshall and coronary sinus musculature

INTRODUCTION

Herein, we present a rare case of the successful ablation of an accessory pathway (AP) involving the Marshall Bundle (MB) and coronary sinus musculature (CSM) in a 40-year-old man with Wolff-Parkinson-White syndrome.

METHODS AND RESULTS

An orthodromic reciprocating tachycardia (ORT) was inducible with the earliest atrial activation site located at the posterolateral mitral annulus. The local conduction and the cycle length of ORT was prolonged by peri-mitral ablation; however, it failed to block the AP. The atrial insertion of the AP was identified by remapping during ORT at the left atrial ridge, which was away from the mitral annulus, where ablation was successful. Together with the electrophysiological findings in CSM potentials, we conclude that the epicardial MB-CSM connection functioned as the AP in this patient.

CONCLUSION

The novel variant form of AP comprised of MB and CSM should be noted. The atrial insertion of the MB may be the target of catheter ablation.

Hypertrophic Cardiomyopathy and Ventricular Preexcitation in the Young: Cause and Accessory Pathway Characteristics

BACKGROUND

The cause of hypertrophic cardiomyopathy (HCM) in the young is highly varied. Ventricular preexcitation (preexcitation) is well recognized, yet little is known about the specificity for any cause and the characteristics of the responsible accessory pathways (AP).

METHODS

Retrospective cohort study of patients <21 years of age with HCM/preexcitation from 2000 to 2022. The cause of HCM was defined as isolated HCM, storage disorder, metabolic disease, or genetic syndrome. Atrioventricular AP (true AP) were distinguished from fasciculoventricular fibers (FVF) using standard invasive electrophysiology study criteria. AP were defined as high risk if any of the following were <250 ms: shortest preexcited RR interval in atrial fibrillation, shortest paced preexcited cycle length, or anterograde AP effective refractory period.

RESULTS

We identified 345 patients with HCM and 28 (8%) had preexcitation (isolated HCM, 10/220; storage disorder, 8/17; metabolic disease, 5/19; and genetic syndrome, 5/89). Six (21%) patients had clinical atrial fibrillation (1 with shortest preexcited RR interval <250 ms). Twenty-two patients underwent electrophysiology study which identified 23 true AP and 16 FVF. Preexcitation was exclusively FVF mediated in 8 (36%) patients. Five (23%) patients had AP with high-risk conduction properties (including ≥1 patient in each etiologic group). Multiple AP were seen in 8 (36%) and AP plus FVF in 10 (45%) patients. Ablation was acutely successful in 13 of 14 patients with recurrence in 3. One procedure was complicated by complete heart block after ablation of a high-risk midseptal AP. There were significant differences in QRS amplitude and delta wave amplitude between groups. There were no surface ECG features that differentiated AP from FVF.

CONCLUSIONS

Young patients with HCM and preexcitation have a high likelihood of underlying storage disease or metabolic disease. Nonisolated HCM should be suspected in young patients with large QRS and delta wave amplitudes. Surface ECG is not adequate to discriminate preexcitation from a benign FVF from that secondary to potentially life-threatening AP.

Diagnosis and treatment of fetal and pediatric age patients (0-12 years) with Wolff-Parkinson-White syndrome and atrioventricular accessory pathways

Overt or concealed accessory pathways are the anatomic substrates of ventricular preexcitation (VP), Wolff-Parkinson-White syndrome (WPW) and paroxysmal supraventricular tachycardia (PSVT). These arrhythmias are commonly observed in pediatric age. PSVT may occur at any age, from fetus to adulthood, and its symptoms range from none to syncope or heart failure. VP too can range from no symptoms to sudden cardiac death. Therefore, these arrhythmias frequently need risk stratification, electrophysiologic study, drug or ablation treatment. In this review of the literature, recommendations are given for diagnosis and treatment of fetal and pediatric age (≤12 years) WPW, VP, PSVT, and criteria for sport participation.

Using 2D speckle-tracking echocardiography to localize the accessory pathway and evaluate cardiac function and dyssynchrony in pediatric patients with Wolf-Parkinson-White syndrome

Wolf-Parkinson-White (WPW) accessory pathway (AP) may be associated with reentry supraventricular tachycardia (SVT) in addition to ventricular dyssynchrony and cardiac dysfunction. Electrophysiological studies (EPS) are the gold standard for the localization of the AP; however, 2D speckle-tracking echocardiography (2D-STE) may help in the localization of the AP noninvasively. Our study aims to evaluate the capability of 2D-STE for AP localization and the identification of AP-related contractile abnormalities and dyssynchrony in pediatric patients with WPW syndrome. This prospective multicenter cohort study involved 18 pediatric patients with ventricular preexcitation from January 2021 to January 2023. Tissue Doppler imaging (TDI), conventional echocardiography, and 2D-STE were done. Myocardial velocities, myocardial performance index (MPI), the global and segmental longitudinal strain of the left ventricle (LV), and time-to-peak longitudinal strain (TPLS) were measured before and after ablation. The longitudinal strain of the LV segments supplied by the AP, or the nearby segments close to the AP, was significantly impaired and improved after ablation (P = 0.0001). The abnormal strain pattern in the affected segments could predict the location of the AP. The TPLS of the affected segments significantly increased after ablation (P = 0.0001), denoting improved dyssynchrony. The ejection time and the LV MPI measured at the basal septum improved significantly after ablation.

CONCLUSIONS

2D STE may be used for noninvasive localization of the AP and to evaluate cardiac function and dyssynchrony in patients with WPW. Further research on more patients is necessary to validate this method for AP localization.

WHAT IS KNOWN

• Accessory pathways (AP) associated with the Wolf-Parkinson-White (WPW) syndrome have been linked to supraventricular tachycardia (SVT). Even without SVT, WPW can cause left ventricular dyssynchrony, contractile dysfunction, and cardiomyopathy. • Electrophysiology study is the gold standard for the localization of the AP in WPW syndrome.

WHAT IS NEW

• The combination of 2D-speckle-tracking echocardiography (2D-STE) and the modified Arruda algorithm can precisely localize the AP associated with WPW syndrome. • 2D-STE can potentially assess cardiac function and dyssynchrony related to WPW syndrome. Additionally, 2D-STE can be utilized to evaluate the effectiveness of ablation in restoring cardiac function and dyssynchrony.

The Wolff-Parkinson-White pattern in neonates: results from a large population-based cohort study

AIMS

Wolff-Parkinson-White (WPW) syndrome is a conduction disorder characterized by an accessory electrical pathway between the atria and ventricles, which may predispose to supraventricular tachycardia (SVT) and sudden cardiac death. It can be seen as an isolated finding or associated with structural heart disease. Our aims were to determine the prevalence of a WPW pattern in a large and unselected cohort of neonates and to describe the electro- and echocardiographic characteristics as well as the natural history during early childhood.

METHODS AND RESULTS

Electrocardiograms and echocardiograms of neonates (aged 0-30 days) from a large, prospective, population-based cohort study were included. Neonates with a WPW pattern were identified and matched 1:4 to controls. Localization of the accessory pathway was assessed by different algorithms. Among 17 489 neonates, we identified 17 (76% boys) with a WPW pattern consistent with a prevalence of 0.1%. One neonate had moderate mitral regurgitation while other echocardiographic parameters were similar between cases and controls (all P > 0.05). The accessory pathways were primarily predicted to be left-sided. At follow-up (available in 14/17 children; mean age 3.2 years) the pre-excitation pattern persisted in only four of the children and none of the children had experienced any episodes of SVT.

CONCLUSION

The prevalence of a WPW pattern in our cohort of unselected neonates was 0.1%. The WPW pattern was more frequent in boys and generally not associated with structural heart disease, and the accessory pathways were primarily left-sided. At follow-up, the WPW pattern had disappeared in most of the children suggesting either an intermittent nature or that normalization occurs.

CLINICAL TRIAL REGISTRATION

Copenhagen Baby Heart, NCT02753348.

A Rare Case of Wolff-Parkinson-White Syndrome Associated with Right Atrial Aneurysm

Wolff-Parkinson-White syndrome is rarely associated with a right atrial aneurysm. However, when such a condition occurs, it will be hard to manage since pre-excitation will be induced as long as the aneurysm persists. A 14-year-old female patient received emergency treatment for irregular wide QRS complex tachycardia in our center, and a pre-excitation pattern was then observed on the surface electrocardiogram. An initial electrophysiological study revealed a high-risk right posterior accessory pathway that was resistant to both radiofrequency and irrigated radiofrequency ablations. Subsequently, fluoroscopy showed that this was due to a right atrial aneurysm. Although successful ablation with irrigated radiofrequency was performed in the second procedure, the procedure was considered suboptimal due to the association of aneurysm. Accordingly, we initiated anti-thrombotic and anti-arrhythmic drug therapy. We decided to omit surgery and followed the case under medical treatment for 2 years without complications. Here, we report this rare coexistence and our treatment approach in detail.

[Not Available]

In this case report, a previously asymptomatic 11-year-old boy presented with sudden palpitations and syncope. He eventually went into cardiac arrest and was successfully resuscitated. The ECG showed pre-excited atrial fibrillation degenerating into pulseless ventricular tachycardia. The patient was found to have Wolff-Parkinson-White syndrome (WPW) with an accessory pathway between right atrium and ventricle which was successfully ablated. Sudden cardiac death (SCD) is rare in WPW, however, early diagnosis is essential for eliminating the risk of SCD.

Successful catheter ablation of a left posterolateral accessory bypass tract and periinterventional management in a patient with MELAS syndrome

MELAS syndrome is defined as a combination of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes resulting from mutations in mitochondrial DNA. All medical interventions in these patients appear challenging due to a high risk of lactate acidosis or anesthesiological complications. Of note, previous reports suggest that these patients have a higher incidence of Wolff-Parkinson-White (WPW) syndrome. Here, a case of successful catheter ablation of a posteroseptal bypass tract using analgosedation in a patient with MELAS syndrome combined with WPW syndrome is presented.

Electrocardiographic abnormalities in a patient with pre-excitation and acute myocardial infarction undergoing percutaneous coronary intervention and ablation

Pre-excitation syndrome can either mimic or mask myocardial infarction, making the diagnosis of acute myocardial infarction difficult. Herein, we report the case of a male patient with Wolf-Parkinson-White (WPW) syndrome who presented to our emergency department with severe chest pain. Non-ST-elevation myocardial infarction was suspected because of cardiac enzyme elevation and abnormal ST-T changes identified through electrocardiography. The patient underwent percutaneous coronary intervention; a left anterior descending artery stenotic lesion was dilated, and drug-eluting stents were implanted. One month later, he underwent successful radiofrequency catheter ablation for his accessory pathway and tachycardia. We present the series of electrocardiographic ST-T abnormalities to raise awareness of the value of diagnosing myocardial injury early in patients with WPW syndrome.

Pediatric T-wave memory after accessory pathway ablation in Wolff-Parkinson-White syndrome

BACKGROUND

Altered ventricular depolarization due to manifest accessory pathway conduction (ie, Wolff-Parkinson-White syndrome) leads to repolarization abnormalities that persist after pathway ablation. The term T-wave memory (TWM) has been applied to these changes, as the postablation T-wave vector "remembers" the pre-excited QRS vector. In adults, these abnormalities can be misinterpreted as ischemia leading to unnecessary interventions. To date, no comprehensive studies have evaluated this phenomenon in the pediatric population.

OBJECTIVE

The purpose of this study was to define TWM in the pediatric population, identify preablation risk factors, and delineate the timeline of recovery.

METHODS

Pre- and postablation electrocardiograms (ECGs) in patients ≤25 years were analyzed over a 5-year period. Frontal plane QTc interval, T-wave axis, QRST angle, and T-wave inversions were used to identify patients with TWM. Univariate analysis was performed to determine the association of preablation ECG features with the outcome of TWM.

RESULTS

TWM was present in 42% of pediatric patients, with resolution occurring within 3 months of ablation. Preablation QRS axis <0° was a strong predictor of TWM (odds ratio [OR] 15.2; 95% confidence interval [CI] 5.7-40), followed by posteroseptal pathway location (right posteroseptal-OR 8.9; 95% CI 4.2-18.8; left posteroseptal-OR 6.1; 95% CI 1.7-22.3). The degree of pre-excitation had a modest association with the development of TWM. No adverse events were observed.

CONCLUSION

TWM is less common in children compared to adults, and normalization occurred within 3 months postablation. The most predictive features for the development of TWM include a leftward pre-excited QRS axis and posteroseptal pathway location.

Incidence of life-threatening events in children with Wolff-Parkinson-White syndrome: Analysis of a large claims database

BACKGROUND

Previous estimates of life-threatening event (LTE) risk in Wolff-Parkinson-White (WPW) syndrome are limited by selection bias inherent to tertiary referral-based cohorts.

OBJECTIVE

This analysis sought to measure LTE incidence in children with WPW syndrome in a large contemporary representative population.

METHODS

A retrospective cohort study was conducted using claims data from the IBM MarketScan Research Databases, evaluating patients with WPW syndrome (age 1-18 years) from any encounter between January 1, 2013, and December 31, 2018. Subjects with congenital heart disease and cardiomyopathy were excluded. The primary outcome was diagnosis of ventricular fibrillation (VF); a composite outcome, LTE, was defined as occurrence of VF and/or cardiac arrest. VF and LTE rates were compared to matched representative controls without WPW syndrome (3:1 ratio).

RESULTS

The prevalence of WPW syndrome was 0.03% (8733/26,684,581) over a median follow-up of 1.6 years (interquartile range 0.7-2.9 years). Excluding congenital heart disease/cardiomyopathy, 6946 subjects were analyzed. LTE occurred in 49 subjects, including VF in 20. The incidence of VF was 0.8 events per 1000 person-years, and the incidence of LTE was 1.9 events per 1000 person-years. There were no occurrences of VF in controls; the rate of LTE was 70 times higher in patients with WPW syndrome (0.7%; 95% confidence interval 0.5%-0.9%) than in controls (0.01%; 95% confidence interval 0%-0.02%).

CONCLUSION

The use of a large claims data set allowed for an evaluation of VF and LTE risk in an unselected pediatric population with WPW syndrome. The observed range of 0.8-1.9 events per 1000 person-years is consistent with prior reports from selected populations. A comparison of event rates to matched controls confirms and quantifies the significant elevation in VF and LTE risk in pediatric WPW syndrome.

Assessment of P- to delta-wave interval and its relationship with accessory pathway properties in patients with pre-excitation

BACKGROUND

The first clinical manifestation of the Wolff-Parkinson-White syndrome in previously asymptomatic individuals may be sudden cardiac death. The options for non-invasive risk stratification are limited in the current era beyond ambulatory rhythm monitoring and an exercise stress test. In our study, we sought to investigate whether there was a relationship between the shortest measured P- to delta-wave time interval (PDI) on the conduction properties of surface electrocardiogram and accessory pathways expressed as antegrade effective refractory period (APERP).

METHODS

Demographic data, symptom status, electrocardiograms (ECG) and intra-cardiac recordings of invasive electrophysiology testing of 103 patients who underwent accessory pathway ablation procedures were collected. Exclusion criteria were: (1) intermittently occurring pre-excitation, which was detected in previous ECGs, (2) delta-wave resolution on treadmill test, (3) presence of multiple accessory pathways, and (4) accessory pathway locations other than the septum. The PDI was measured as the time interval from the beginning of the P wave to the earliest upstroke or downstroke of the delta wave on V1 and V2 derivations of the surface ECG, and the shortest measurement was recorded.

RESULTS

Patients were grouped into two groups: group I, if APERP was < 240 ms and group II if APERP was ≥ 240 ms. PDI was significantly shorter in group II. By correlation analysis, a positive and moderate correlation between PDI and APERP (r = 0.598, p < 0.001) and PDI and age (r = 0.800, p < 0.001) was found, and a negative and moderate correlation between PDI and inducible AF (r = -492, p < 0.001). The best cut-off value for PDI to predict APERP ≥ 240 was 90.5 ms with a sensitivity of 80% and a specificity of 83%.

CONCLUSIONS

Our results demonstrate that there was a strong correlation between the P- to delta-wave interval and universally accepted risk factors, such as low age, low APERP and atrial fibrillation inducibility. Further studies with larger patient groups and follow-up data are needed to appraise its predictive value.

Sequential Abolition of Antegrade and Retrograde Conduction in Wolff-Parkinson-White Syndrome: A Case Series

BACKGROUND Radiofrequency ablation in cases of Wolff-Parkinson-White (WPW) syndrome is a relatively safe procedure that yields good results. However, the electrical characteristics of WPW syndrome have not yet been fully elucidated. Herein, we report 2 cases of WPW syndrome, wherein antegrade conduction was abolished first, followed by retrograde conduction. CASE REPORT Case 1: A 15-year-old boy who recently reported experiencing frequent palpitations was diagnosed with type A WPW syndrome by electrocardiography (ECG). Radiofrequency energy was delivered to the earliest activation site using an ablation catheter. This procedure abolished antegrade accessory pathway conduction in 6 seconds, and then the ablation was continued for 60 seconds; however, retrograde accessory pathway conduction remained intact. Hence, radiofrequency ablation was performed to further deliver radiofrequency energy to abolish the retrograde accessory pathway conduction. Case 2: A 19-year-old woman with palpitations since elementary school was diagnosed with type A WPW syndrome by ECG. Radiofrequency energy was delivered to the earliest activation site through an ablation catheter to abolish antegrade accessory pathway conduction in approximately 1 second, and then the ablation was continued for 60 seconds. Retrograde accessory pathway conduction was preserved, and further radiofrequency ablation performed multiple times in the same vicinity abolished retrograde accessory pathway conduction. CONCLUSIONS We managed 2 cases of WPW syndrome wherein antegrade and retrograde accessory pathway conduction were individually abolished. This phenomenon may have been caused by an incomplete lesion that resulted in a functional block.

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.

Anaesthetic challenges in a patient with Wolff-Parkinson-White (WPW) syndrome for orchidectomy

Wolff-Parkinson-White (WPW) syndrome is an extremely rare congenital cardiac conduction disorder. It is due to an aberrant pathway between the atrium and ventricle. This manuscript entails a man with an underlying WPW who was posted for an elective orchidectomy. We discussed the important perioperative precautions to prevent the precipitation of acute cardiac events.

[Ablation of a para-Hisian accessory pathway with high-power short-duration]

We report the case of a 30-year-old man who presented to our emergency department with rapid heart beat and a narrow complex tachycardia at a rate of 215 beats per minute. With the working diagnosis of Wolf-Parkinson-White syndrome with paroxysmal orthodromic tachycardias, we performed an electrophysiological study. In this examination, there was a para-Hisian accessory pathway with very fast, prognostically relevant conduction properties. In order to protect the His bundle that is located deeper in the tissue and to avoid a deeper lesion, we decided to use high-power short-duration ablation. This method, which was recently used in three-dimensional-controlled radiofrequency ablation of pulmonary veins, causes more superficial lesions in order to protect the surrounding tissue. In our case, using the high-power short-duration method, we were able to successfully ablate the para-Hisian accessory pathway, while protecting the His bundle near the ablation site.

3D-rendered Electromechanical Wave Imaging for Localization of Accessory Pathways in Wolff-Parkinson-White Minors

Arrhythmia localization prior to catheter ablation is critical for clinical decision making and treatment planning. The current standard lies in 12-lead electrocardiogram (ECG) interpretation, but this method is non-specific and anatomically limited. Accurate localization requires intracardiac catheter mapping prior to ablation. Electromechanical Wave Imaging (EWI) is a high frame-rate ultrasound modality capable of non-invasively mapping the electromechanical activation in all cardiac chambers in vivo. In this study, we evaluate 3D-rendered EWI as a technique for consistently localizing the accessory pathway (AP) in Wolff-Parkinson-White (WPW) pediatric patients. A 2000 Hz EWI diverging sequence was used to transthoracically image 13 patients with evidence of ECG pre-excitation, immediately prior to catheter ablation and after successful ablation whenever possible. 3D-rendered activation maps were generated by co-registering and interpolating the 4 resulting multi-2D isochrones. A blinded electrophysiologist predicted the AP location on 12-lead ECG prior to ablation. Double-blinded EWI isochrones and clinician assessments were compared to the successful ablation site as confirmed by intracardiac mapping using a segmented template of the heart with 19 ventricular regions. 3D-rendered EWI was shown capable of consistently localizing AP in all the WPW cases. Clinical ECG interpretation correctly predicted the origin with an accuracy of 53.8%, respectively 84.6% when considering predictions in immediately adjacent segments correct. Our method was also capable of assessing the difference in activation pattern from before to after successful ablation on the same patient. These findings indicate that EWI could inform current diagnosis and expedite treatment planning of WPW ablation procedures.

Localization Of Accessory Pathways In Wolff Parkinson White Syndrome Using R/S Ratios On Surface Ecgs

BACKGROUND

This study was conducted to establish the accuracy of R/S ratios in localizing accessory pathways in Wolff Parkinson White Syndrome on surface ECGs.

METHODS

This was a retrospective cross-sectional study from January 2002 till December 2016 conducted at National Institute of Cardiovascular diseases in Karachi, Pakistan. The sample included 157 patients with manifesting Wolff Parkinson White (WPW) Syndrome on a 12-lead surface ECG. As per the inclusion criteria, patients who had persistent or intermittent pre-excitation on surface ECG and had undergone electrophysiological study (EP) were included in the sample. Individuals with both successful and unsuccessful ablation procedures were included.

RESULTS

The sample consisted of 62.4% males (n=98) and 37.6% females (n=59) with mean age being 35.36±12.44. Accessory pathways (APs) were identified on the left side in majority of the patients with 54.1% (n=85) while right sided pathways were seen in 42.1% (n=66). Moreover, the most common accessory pathway amongst the males was Left Anterior (LA) and Left Lateral (LL) with a percentage of 48%, followed by Right Posteroseptal (RPS) at 20.4%. As opposed to this, the most common pathways amongst the females turned out to be RPS at 33.9% followed by LL and LA at 32.2%. Furthermore, the test using ratios were most effective in identifying left sided APs with sensitivity 74.1% and was least sensitive in identifying right sided pathways (sensitivity=40.7%). However, it was highly specific in locating right sided pathways with specificity of 94.6% as opposed to 83.3% in the left side. Furthermore, mid-septum regions had a sensitivity and specificity of 66.7% and 69.6% respectively.

CONCLUSIONS

This establishes the effectiveness of R/S ratios in determining the location of accessory pathway based on the surface ECG prior to the ablation procedure. Since the younger population is affected more commonly, prolonged exposure to ionizing radiation can cause long term complications therefore, by this means, the duration of exposure can be reduced.

Cardiac electrophysiologic procedures - A ten years' experience at National Institute of Cardiovascular Diseases, Karachi

OBJECTIVE

To review 10 years of clinical practice of cardiac electrophysiology study and radiofrequency catheter ablation in the treatment of supraventricular tachycardia.

METHODS

The retrospective chart review was conducted at the National Institute of Cardiovascular Diseases, Karachi, and comprised records of all patients who underwent electrophysiological study and / or radiofrequency catheter ablation from January2007 to December 2016. SPSS 21 was used for data analysis.

RESULTS

Of the 627 patients, 335(53.4%) were females. The overall mean age was 40.99}13.59 years. The major indication for procedure was supraventricular tachycardia 376(59.97%). Final electrophysiological study diagnosis was typical slow fast atrioventricular nodal re-entrant tachycardia in 303(48.3%) patients. The overall success rate was 472(75.3%). Procedure-related complications were reported in 25(4%) patients, and there was 1(0.15%) mortality.

CONCLUSIONS

Cardiac electrophysiology studies and radiofrequency catheter ablation were found to be an effective and safe method for diagnosis and treatment of supraventricular tachycardia.

Wolf Parkinson White Syndrome: So Close Yet So Far

Wolf-Parkinson-white (WPW) syndrome is a common heart disorder, however diagnosis is not frequently made. Outcome appears more favourable than in other heart conditions, however could be fatal. In this case series, three young Nigerian females presented with non-specific symptoms and were diagnosed with the classical electrocardiogram. Definitive diagnosis and treatment is still unavailable in the country. One came with a complication that reverted after treatment.

A Case of Multiple Cardiovascular and Tracheal Anomalies Presented with Wolff-Parkinson-White Syndrome in a Middle-aged Adult

Congenital cardiovascular anomalies, such as dextrocardia, persistent left superior vena cava (SVC), and pulmonary artery (PA) sling, are rare disorders. These congenital anomalies can occur alone, or coincide with other congenital malformations. In the majority of cases, congenital anomalies are detected early in life by certain signs and symptoms. A 56-year-old man with no previous medical history was admitted due to recurrent wide QRS complex tachycardia with hemodynamic collapse. A chest radiograph showed dextrocardia. After synchronized cardioversion, an electrocardiogram revealed Wolff-Parkinson-White (WPW) syndrome. Persistent left SVC, PA sling, and right tracheal bronchus were also detected by a chest computed tomography (CT) scan. He was diagnosed with paroxysmal supraventricular tachycardia (PSVT) associated with WPW syndrome, and underwent radiofrequency ablation. We reported the first case of situs solitus dextrocardia coexisting with persistent left SVC, PA sling and right tracheal bronchus presented with WPW and PSVT in a middle-aged adult. In patients with a cardiovascular anomaly, clinicians should consider thorough evaluation of possibly combined cardiovascular and airway malformations and cardiac dysrhythmia.

Successful Catheter Ablation as a Substitute for Cardiac Resynchronization Therapy in Patient with an Accessory Pathway-induced Cardiomyopathy

A 50-year-old man presented with exertional dyspnea and orthopnea. An electrocardiogram showed a delta wave and a wide QRS complex, similar to left bundle branch block. Cardiac echocardiography revealed diffuse severe hypokinesis and dyssynchrony. The patient was diagnosed with congestive heart failure. We considered that the patient's condition was caused by an accessory pathway-induced cardiomyopathy after heart failure compensation with guideline-oriented medical therapy. We therefore performed catheter ablation for right-sided pre-excitation syndrome as cardiac resynchronization therapy. The left ventricular dyssynchrony was resolved immediately after the procedure, and the patient's ventricular contraction improved, with a reduced cardiac volume at 6 months after the procedure-thus suggesting that the accessory pathway had affected the patient's cardiac function.

Comparative Assessment of the Heart's Functioning by Using the Akabane Test and Classical Methods of Instrumental Examination

Acupuncture physicians have studied the application of reflexotherapy to cardiology. However, no one has investigated the connection of ancient Chinese diagnostic methods with modern tools. A total of 102 patients (54 men and 48 women) with heart pathology, namely, sick-sinus syndrome, Wolff-Parkinson-White syndrome, and atrioventricular blockade, were studied using the usual instrumental methods (transesophageal electrophysiological study of the heart, echocardiography), after which they underwent Akabane thermopuncture testing as in traditional Chinese medicine. The results of cardio examination from one side of the Akabane test with that from the other side were compared by means of a multiple stepwise regression analysis. We revealed the effects on the characteristic pattern of acupuncture channel lesions inherent in a definite heart pathology, i.e., the most vulnerable acupuncture channel (AC), of such factors as disturbances of the contractile, conductive, or automatic heart functions, and changes in the chambers' size or circulation volume. Сhanges in the indices of the left and the right branches of these channels usually reflect the opposing natures of the changes in these indicators, which should be considered in reflexotherapy. The main value of the Akabane test along with the use of mathematical analysis lies in early, quick, and inexpensive detection of the above-mentioned heart disturbances.

Ebstein's Anomaly Associated with Atrial Septal Defect and Wolff-Parkinson-White (WPW) Syndrome

Ebstein's anomaly is a rare congenital heart disorder, accounting for <1% of all cases of congenital heart disease. It is a congenital malformation of the heart that is characterized by apical displacement of the septal and posterior tricuspid valve leaflets, leading to atrialization of the right ventricle with a variable degree of malformation and displacement of the anterior leaflet. We report the case of a 25 years old female with Ebstein's anomaly which was associated with Ostium Secundum type of atrial septal defect and WPW syndrome, who presented with dyspnea, palpitations, cyanosis, clubbing and cardiomegaly.

Wolff-Parkinson-White (WPW) syndrome: the detection of delta wave in an electrocardiogram (ECG)

The delta wave remains an important indicator to diagnose the WPW syndrome. In this paper, a new method of detection of delta wave in an ECG signal is proposed. Firstly, using the continuous wavelet transform, the P wave, the QRS complex and the T wave are detected, then their durations are computed after determination of the boundary location (onsets and offsets of the P, QRS and T waves). Secondly, the PR duration, the QRS duration and the upstroke of the QRS complex are used to determine the presence or absence of the delta wave. This algorithm has been tested on the Physionel database (ptbdb) in order to evaluate its robustness. It has been applied to clinical signals from patients affected by WPW syndrome. This method can provide assistance to practitioners in order to detect the WPW syndrome.

Papillary Muscle Rupture in an Adolescent with No Coronary Lesions

A 21-year-old man with Wolff-Parkinson-White syndrome presented to the authors' hospital with ventricular fibrillation. Coronary angiography failed to demonstrate coronary stenosis, but temporary mechanical circulatory support resolved the ventricular fibrillation and the patient was extubated eight days later. On the next day, however, he had to be re-intubated with symptoms of congestive heart failure. Echocardiography revealed new severe mitral regurgitation and a mobile mass, while emergency surgery revealed a posteromedial papillary muscle rupture (PMR). The mitral regurgitation was repaired with ruptured papillary muscle relocation, artificial chordae implantation, and ring annuloplasty. Postoperative examinations suggested that an arrhythmia-induced coronary circulation hypoperfusion and septic embolization had caused the PMR.

[AV-reentrant tachycardia and Wolff-Parkinson-White syndrome : Diagnosis and treatment]

The AV-reentrant tachycardia (AVRT) is a supraventricular tachycardia with an incidence of 1-3/1000. The pathophysiological basis is an accessory atrioventricular pathway (AP). Patients with AVRT typically present with palpitations, an on-off characteristic, anxiety, dyspnea, and polyuria. This type of tachycardia may often be terminated by vagal maneuvers. Although the clinical presentation of AVRT is quite similar to AV-nodal reentrant tachycardias, the correct diagnosis is often facilitated by analyzing a standard 12-lead ECG at normal heart rate showing ventricular preexcitation. Curative catheter ablation of the AP represents the therapy of choice in symptomatic patients. This article is the fourth part of a series written to improve the professional education of young electrophysiologists. It explains pathophysiology, symptoms, and electrophysiological findings of an invasive EP study. It focusses on mapping and ablation of accessory pathways.

Irregular Wide Complex Tachycardia in a Young Man

Wolf Parkinson White syndrome is a pre-excitation syndrome due to an accessory conduction pathway. Electrocardiography demonstrates a short PR interval, long QRS interval and delta waves in normal sinus rhythm. Atrial fibrillation with underlying Wolf Parkinson White syndrome presents with irregular wide complex tachycardia, and can cause sudden cardiac death by precipitating ventricular fibrillation. Irregular wide complex tachycardia may be the first presentation of this underlying conduction abnormality in young patients. Emergency management for irregular wide complex tachycardia in hemodynamically unstable patients involves synchronized cardioversion, while intra-venous Procainamide can be used in hemodynamically stable patients. AV nodal blocking agents should be avoided. Treatment of choice for WPW syndrome is radiofrequency ablation.

Thyroid storm in a patient with Wolff-Parkinson-White syndrome

A 44-year-old woman with no medical history presented to the emergency department with a 2 h history of sudden onset chest pressure, palpitations, diaphoresis and shortness of breath. She reported a 90-pound unintentional weight loss, increased appetite, irritability, night sweats and palpitations for 2 months. Physical examination revealed a heart rate (HR) of 269 bpm and a blood pressure of 116/94 mm Hg. Her ECG revealed a wide-complex tachycardia with right bundle branch morphology and an HR of 265 bpm. Intravenous adenosine was administered with resolution of the arrhythmia and symptoms. Her subsequent ECG revealed sinus tachycardia with δ waves, which was consistent with Wolff-Parkinson-White (WPW) syndrome. Laboratory findings confirmed thyroid storm and treatment began with intravenous hydrocortisone, methimazole, metoprolol, amiodarone and iodine drops. Graves' disease was confirmed based on the presence of serum thyroid-stimulating hormone receptor antibody. The patient underwent successful WPW accessory tract ablation 6 weeks after initial presentation.

Sports-Related Sudden Cardiac Injury or Death

Symptoms such as syncope and chest pain, especially if they are accompanied by palpitations or occur with exercise in any combination, require cardiac evaluation before adolescent athletes are allowed to return to the sports field. Some life-threatening conditions will likely be associated with a family history of HCM or LQTS, but the family history may not be discovered at the first medical visit. A family history of CPVT, for example, is hard to elicit unless this diagnosis has already been established in an affected family member. The keys will be the timing of symptoms and the documentation of arrhythmia with exercise. The ECG at baseline in CPVT may be deceptively normal. Hypertrophic cardiomyopathy is progressive, so evaluation during early childhood may be negative. Long QT syndrome may not always result in an abnormal ECG, even in genetically positive individuals. A high index of suspicion is needed to make these diagnoses, especially if the family history is not available.