Intra-Atrial Conduction Block Along the Mitral Valve Annulus During Accessory Pathway Ablation: Evidence for a Left Atrial "Isthmus (original) (raw)
Shortening of ventriculoatrial interval after ablation of an accessory pathway
Indian pacing and electrophysiology journal, 2006
A 21-year old man with history of 8 year palpitation was referred for electrophysiologic study and possible radiofrequency ablation. Physical examination and transthoracic echocardiographic study did not disclose any abnormality. Baseline ECG showed normal sinus rhythm with normal PR and QRS intervals and no evidence of preexcitation. Antiarrhythmic drugs (propranolol and verapamil) were discontinued two days before the procedure. Baseline intervals in sinus rhythm were as follows: sinus cycle length=690 msec, AH=74 msec, HV=37 msec, QRS=90 msec, PR=133 msec. The minimal pacing cycle length maintaining 1:1 antegrade conduction (AVWP) was 320 msec and the minimal pacing cycle length maintaining 1:1 retrograde conduction (VAWP) was 400 msec. Single extrastimulus testing in the right atrium and the right ventricular apex leaded to a sustained narrow complex tachycardia. The arrhythmia was a short PR-long RP tachycardia with following characteristics: cycle length=376 msec, AH=141 msec, HV=42 msec, VA=200 msec, HA (HRA) =236 msec, HA (His) =243 msec and eccentric atrial activation during the arrhythmia . The arrhythmia was easily reproducible with stable hemodynamic.
Pacing and clinical electrophysiology : PACE, 2014
Case Presentation A 15-year-old boy presented to the electrophysiology laboratory with a history of paroxysmal narrow complex tachycardia. A sinus rhythm 12-lead surface electrocardiogram demonstrated ventricular pre-excitation with morphology suggestive of a left lateral accessory pathway. A short RP tachycardia at a cycle length of 220 beats/min was induced. The tachycardia had features of orthodromic atrioventricular (AV) reentrant tachycardia with earliest atrial signal in distal coronary sinus (CS) electrodes. Ventricular pacing showed earliest retrograde atrial signal in distal CS (Fig. 1A). Endocardial ablation lesion at the site of earliest atrial activation with fused ventricular and atrial signal during right ventricular pacing was placed with a 5-mm nonirrigated-tip radiofrequency ablation catheter. This eliminated anterograde accessory pathway conduction and altered the retrograde activation sequence of the atrium with ventricular pacing (Fig. 1B). However, there was evidence of persistent retrograde accessory pathway conduction with administration of adenosine. A single lesion placed in the CS guided by mapping inside the CS near bipoles CS 3,4 led to loss of retrograde atrial activation (Fig. 2). Sharp late signals at the end of the paced ventricular electrograms were still present in two of the distal electrode pairs of the CS (Fig. 2). What does the change in atrial activation sequence in the CS suggest? Are there more than one accessory pathways present? Are these late potentials at the end of the ventricular signals in the lateral CS electrode pairs a part of
Radiofrequency Ablation of Atrial Insertion of Left-Sided Accessory Pathways Guided by the "W Sign
Journal of Cardiovascular Electrophysiology, 1995
AP Ablation and the ^'W Sign." introduction: The aim of this study was to evaluate the efficacy of radiofrequency <RF) ablation of the atrial insertion of left-sided aceessory pathways with guidance hy a specific morphologic characteristic of the local electrogram, which we call the "W sign," This represents the shortest local atrioventricular (AV) interval during sinus rhythm in patients with manifest preexeitation or the shortest local VA interval during AV reciprocating tachycardia and/or ventricular pacing in patients with concealed accessory pathways.
Heart, 1997
Objective-To identify possible factors associated with primary failure of radiofrequency ablation of accessory pathways or recurrence of accessory pathway conduction. Patients and methods-Radiofrequency ablation of accessory pathways failed in 25 of 243 patients, and recurrence of accessory pathway conduction occurred in an additional 13 patients. Factors possibly related to primary failure and recurrence were analysed. Results-Primary failure and recurrence were less frequent in patients with left sided pathways (7% v 19%; 4% v 24%; P = 0.04). The factors that might relate to primary failure included an unstable catheter position (seven patients), a possible epicardial pathway (six patients), or misdiagnosis of accessory pathway location (two patients). The major factors for recurrence included the stability of the local atrial electrogram < 0 5 together with the stability of the local ventricular electrogram < 0.8, and prolonged time to pathway conduction block > 12 seconds). Thirty one patients underwent repeat ablation which was successful in 28. Conclusions-Primary failure and recurrence were more frequent in patients with right sided pathways. An unstable catheter position and a possible epicardial pathway location are the main contributing factors for primary failure, while unstable local electrograms and prolonged time to block are independent predictors for recurrence.
Complete left atrial ablation with bipolar radiofrequency☆☆☆
European Journal of Cardio-Thoracic Surgery, 2008
Objective: Despite its efficacy and swiftness, bipolar radiofrequency is generally not used on the left isthmus for concern of injuring a coronary branch. Incomplete lesion sets or use of an additional unipolar device are often considered. We report a technique to perform a full left lesion set involving the mitral line using a standard bipolar radiofrequency device. Methods: An innovative complete left atrial lesion set was performed using only bipolar radiofrequency in 70 consecutive patients (study group). In 67/70 patients (96%) mitral valve disease was the main indication to surgery. Atrial fibrillation was permanent in 42 patients (60%), persistent in 25 (36%) and paroxysmal in three patients (4%). After beating-heart pulmonary vein isolation on-pump, the coronary-free area of the AV groove was marked epicardially by sticking a needle into the left atrial wall, behind the coronary sinus. The projection of the needle marker on the mitral annulus was then identified through the atriotomy and an endo-epicardial ablation was performed with the bipolar device involving the atrial wall, the coronary sinus, up to the annulus. The lesion set was then completed by connecting the encirclings and the left appendage, which was then sutured. Followup was 100% complete. Results were compared with those of a control group of 33 patients receiving bipolar radiofrequency left atrial ablations and a mitral connecting line with a second unipolar device. Results: All patients survived. No major complication occurred. Haematoma of the AV groove was observed during retrograde cardioplegia in one case. No myocardial ischaemia or re-exploration for bleeding (median 325 cc, interquartile range 250-442) occurred. Two out of 70 patients required a permanent pacemaker for AV block. Freedom from atrial fibrillation was 84% (95% CI: 75%, 93%) at 6 months and 81% (95% CI: 70%, 93%) at 1 year. One patient had left flutter. Comparison with the control group did not show any difference in clinical outcomes, but revealed bipolar ablation to the mitral annulus to abate the per patient cost of the ablation devices (1245 AE 50 s vs 2403 AE 17 s; p < 0.0001). Conclusions: Performing the mitral line with bipolar radiofrequency is safe and cost-effective. A complete left atrial ablation with a single bipolar radiofrequency device yields excellent clinical mid-term results. #
Catheter technique for ablation of accessory atrioventricular pathway: long-term results
European heart journal, 1989
Catheter ablation of an accessory atrioventricular pathway was attempted in six patients with recurrent tachyarrhythmias resistant to medication (four to five trials). Localization of the accessory pathway was performed by potential recordings with an electrode catheter from the region of the tricuspid and mitral valve rings during orthodromic supraventricular tachycardia (n = 4), during sinus rhythm (n = 1), and during ventricular pacing (n = 1). Using this mapping technique, the site of earliest atrial or ventricular activation through the accessory pathway was localized in the anterior septal (n = 2), right free wall (n = 2), posterior septal (n = 2), or left free wall (n = 1) region of the atrioventricular valve rings. The shortest ventriculo-atrial (VA) and atrio-ventricular (AV) intervals measured in the local electrograms ranged from VA = 45-70 ms, and AV = 45-65 ms, respectively. The accessory pathway responsible for the arrhythmia demonstrated exclusive retrograde (n = 4) o...
Pacing and Clinical Electrophysiology
Catheter ablation of accessory pathways using radiofrequency current has been shown to be effective in patients with Wolff-Parkinson-White syndrome, by using either the ventricular or atrial approach. However, the unipolar electrogram criteria for identifying a successful ablation at the atrial site are not well established. One hundred patients with Wolff-Parkinson-White were treated by delivering radiofrequency energy at the atrial site. Attempts were considered successful when ablation (disappearance of the delta wave) occurred in < 10 seconds. In eight patients with concealed pathway, the accessory pathway location was obtained by measuring the shortest V-A interval either during ventricular pacing or spontaneous or induced reciprocating tachycardia. In 92 patients both atrioventricular valve annuli were mapped during sinus rhythm, in order to identify the accessory pathway (K) potential before starting the ablation procedure. When a stable filtered (30-250 Hz) "unipolar...