Risk Factors of Adverse Presentation as the First Arrhythmia in Wolff‐Parkinson‐White Syndrome

Background: The aim of the study was the evaluation of the predictors of adverse presentation as first arrhythmia in Wolff‐Parkinson‐White syndrome; they usually affect young patients with septal or multiple accessory pathways (AP). Methods: Our population comprised 645 patients with a preexcitation syndrome. Among them, adverse presentation (sudden death, hemodynamically not tolerated atrial fibrillation [AF]) occurred in 60 (9%) (group I). Their clinical and electrophysiological features were compared to group II patients, which consisted of 75 patients with syncope (IIa), 287 with reentrant tachycardia (RT) (IIb), 211 asymptomatic patients (IIc), and 12 with well‐tolerated AF. Results: Sixteen group I patients had triggering factors. Group I patients were older (40 ± 18.5) than group II (34 ± 16) (P = 0.02). Male gender was as frequent in both groups (63%, 59%). Free wall left AP was more frequent in group I (65%) than in group II (37%) (P < 0.001), septal AP less frequent (27% vs 47%) (P = 0.004), multiple APs exceptional. RT was more frequent in group I (57%) than in group IIc (12%) (P < 0.001), less frequent than in group IIb (90.5%) (P < 0.001). AF was more frequent in group I (85%) than in group IIc (22%), or IIb (19%) (P < 0.001). Maximal rate through AP was higher in group I than in group II (P < 0.001). Conclusions: Adverse presentation in WPW may affect patients older than 35 years of both sexes, with a single free wall lateral AP. All could have been identified by an electrophysiological study. (PACE 2010; 33:1074–1081)     

Risk Stratification in Wolff‐Parkinson‐White Syndrome: The Correlation Between Noninvasive and Invasive Testing in Pediatric Patients

Background: In Wolff‐Parkinson‐White (WPW) syndrome, rapid antegrade conduction of atrial tachyarrhythmias can result in ventricular fibrillation and sudden death. Antegrade conduction can be assessed through noninvasive testing or invasive electrophysiology study (EPS). We aimed to determine the correlation between noninvasive testing and EPS in a pediatric WPW population. Methods: All WPW patients <21 years who underwent EPS over a 10‐year period were identified. Noninvasive testing reviewed included electrocardiogram, Holter, and exercise stress test (EST). Patients were classified as low‐risk if preexcitation was lost during any test. EPS data reviewed included antegrade conduction during atrial pacing and atrial fibrillation. Conduction through the accessory pathway (AP) to a cycle length ≤250 ms was considered rapid, otherwise patients were nonrapid. Sensitivity, specificity, positive (PPV), and negative predictive value (NPV) of noninvasive testing to correctly identify nonrapid conduction was calculated. Results: There were 135 EPS. Twenty‐four patients (18%) were classified low‐risk noninvasively. Two of the 24 (8%) had rapid conduction at baseline EPS. The sensitivity, specificity, PPV, and NPV of low‐risk noninvasive testing to predict nonrapid conduction was 22%, 94%, 92%, and 31%, respectively. Sixteen of the 24 had low‐risk EST and none had rapid conduction at baseline EPS. The specificity and PPV of low‐risk EST were 100%. Conclusion: Loss of preexcitation during noninvasive testing had high specificity and PPV for nonrapid antegrade conduction during baseline EPS. Abrupt loss of preexcitation during EST was a highly reliable noninvasive marker of nonrapid AP conduction at baseline in our pediatric WPW patients. (PACE 2012;35:1451–1457)     

The Appearance of Ventricular Preexcitation during Exercise Testing Reproduced by Dobutamine Administration

A 33‐year‐old woman presented with exercise‐related palpitations after an apparently successful catheter‐ablation of overt midseptal accessory pathway. Post procedure, the electrocardiogram at rest was normal, while the progressive appearance of delta‐wave during treadmill stress testing was recorded. In addition, the occurrence of ventricular preexcitation was reproduced by controlled administration of dobutamine. Detailed understanding of the unusual pathway electrophysiology resulted in specific planning of the second procedure. In the basal state, pacing maneuvers did not demonstrate any evidence of pathway conduction. However, during infusion of dobutamine bidirectional conduction in the right anterior pathway was restored, enabling definitive cure by radiofrequency. (PACE 2010; 33:766–769)     

Successful ablation of a right atrium−axillary ventricular accessory pathway associated with Wolff‐Parkinson‐White syndrome

We report a case of a patient with right axillary ventricular. Similar congenital anomaly of the right atrium was reported as “right appendage diverticulum or right atrial diverticulum.” However, this independent chamber has its own annulus, synchronizes with the right ventricular, and generates large ventricular potential. Under the guidance of the CARTO mapping system (Biosense Webster, Diamond Bar, CA, USA), a right atrioventricular accessory pathway associated with type B Wolff‐Parkinson‐White syndrome was ablated successfully. This pathway was close to the annulus of the axillary ventricular. The patient remained free of arrhythmia at 1‐year follow‐up.     

M型超声心动图对显性预激综合征旁道的定位

目的： 评价Ｍ 型超声心动图定位显性预激旁道的可行性及准确性。方法： 用Ｍ 超检测了２０例预激患者心室壁的提前收缩部位, 并与射频消融术中心内电生理检查标测的“靶点”比较。结果： 经心内电生理检查证实的左侧显性旁道１５例（共１６ 条）, Ｍ 型超声准确定位１１例（共１２条）, 准确率７５％ （１２／１６）; 右侧显性旁道５例,Ｍ 型超声均未能定位。结论： Ｍ 型超声可对部分左侧显性旁道进行定位。     

ECG Criteria for Accurate Localization of Left Anterolateral and Posterolateral Accessory Pathways

Background : Left lateral accessory pathway (AP) location along the mitral annulus (MA) can influence ablation strategy, including choice of a transseptal or retrograde aortic approach and the use of deflectable sheaths and/or bidirectional catheters. We aimed to develop electrocardiographic (ECG) criteria to accurately localize a left lateral AP, hypothesizing that the relationship of QRS amplitudes in limb leads II and III could be used to differentiate left anterolateral (LAL) from left posterolateral (LPL) AP locations. Methods : The ECGs from patients who underwent ablation of a left‐sided AP between 2001 and 2008 were evaluated for the relationship of QRS amplitudes in limb leads II and III. A LAL‐AP was defined by successful ablation between 12 and 3 o’clock on the MA, as seen in left anterior oblique (LAO) fluoroscopic projection. A LPL‐AP was defined by successful ablation between 3 and 6 o’clock in the LAO projection. Results : In 249 consecutive patients undergoing AP ablation, 23 met the prespecified inclusion criteria: manifest preexcitation due to single AP, ablated successfully in a LAL or LPL location. The ratio of dominant QRS amplitude in lead II to lead III was ≥1 in 10/11 patients with LAL‐AP, compared with 3/12 patients with a LPL‐AP (P = 0.002). Using these criteria, two blinded reviewers predicted a LAL or LPL location with 87% accuracy and 100% interobserver agreement. Conclusions : We report new ECG criteria that can be used to accurately predict the anterior and posterior location of a left lateral AP. Such localization may facilitate procedural planning. (PACE 2012;35:1444–1450)     

Coexistent Brugada Syndrome and Wolff‐Parkinson‐White Syndrome: What Is the First Clinical Presentation?

The coexistence of Brugada syndrome and Wolff-Parkinson-White (WPW) syndrome is a very rare phenomenon. We describe a 31-year-old patient without any previous cardiac disorder admitted to our hospital due to palpitations and concomitantly diagnosed as WPW syndrome and treated with radiofrequency catheter ablation. He was later diagnosed with Brugada syndrome and followed-up 2 years without any symptoms. We discuss other previously reported cases in literature, in which these two conditions exist simultaneously.     

Failure of the Exercise Test to Predict the Anterograde Refractory Period of the Accessory Pathway in Wolff Parkinson White Syndrome

Modifications of the delta wave on the surface ECG during an exercise stress test were compared to electrophysiological variations in accessory pathway (AP) refractoriness and in AV node conduction, during intravenous isoproterenol infusion in ten patients with WPW syndrome. In one patient, the delta wave persisted unchanged at the end of exercise and, with isoproterenol, there was a greater reduction in the AP anterograde effective refractory period (AERP) than in AV node conduction time. In three patients, the delta wave became less and less apparent but without completely disappearing; in these patients, the slight reduction of the AERP in the accessory pathway with isoproterenol was comparable to the reduction in AV node conduction time, explaining the progressive fusion between the two activation fronts. In the six other patients, the delta wave completely disappeared during exercise: in two cases, suddenly from one cycle to the next with strong concordance between the measured (isoproterenol) and the estimated (exercise test) AERP in the AP; in four cases, the disappearance was progressive with a significantly greater reduction in the AV node conduction time than in the measured AERP of AP which was nonetheless very short, 190 to 225 ms, during isoproterenol infusion. These findings confirm the limitations of the exercise test to predict the AERP of the AP. In addition, they demonstrate that modifications in the delta wave during exercise result from a balance between the relative effects of sympathetic stimulation on refractoriness of AP and normal AV conduction.     

Cough Syncope Caused by Sinus Arrest in a Patient with Sick Sinus Syndrome

Cough syncope is a syndrome in which dizziness or syncope occurs after prolonged bouts of cough. This paper presents a case of 63-year-old man with recurrent dizziness and syncope. The 24-hour ambulatory electrocardiogram and intracardiac electrogram showed sinus node dysfunction with sinus arrest, both spontaneous and inducible by voluntary cough. Sinus arrest was sometimes associated with dizziness. A permanent VVI pacemaker was implanted and no further cough syncope has occurred. We suggest that sinus arrest may play a role as a mechanism of cough syncope in a patient with sick sinus syndrome.