Search

Background: It remains unknown whether P wave duration (PWD) ≥ 150 ms measured after extensive radiofrequency catheter ablation (RFCA) can identify non-paroxysmal atrial fibrillation (non-PAF) patients at increased risk of atrial tachyarrhythmia recurrence. We investigated the predicting power of PWD and its association with left atrial (LA) reverse remodeling in patients with non-PAF undergoing pulmonary vein isolation with LA linear ablation., Methods: We retrospectively evaluated 136 patients who underwent RFCA for drug-refractory non-PAF. Electroanatomic mapping was acquired during AF. Low-voltage area (LVA) was defined as an area with bipolar voltage ≤0.5 mV. Electrocardiography and echocardiography were performed during sinus rhythm 1 day and 3 months after RFCA. PWD was measured using amplified 12‑lead electrocardiography. Prolonged PWD was defined as maximum PWD ≥ 150 ms., Results: Over a mean follow-up duration of 48 ± 35 months, 28 patients experienced atrial tachyarrhythmia recurrence. PWD was positively correlated with LVA (r = 0.527, p < 0.001) and inversely correlated with LA emptying fraction (r = -0.399, p < 0.001). PWD was shortened and LA emptying fraction (LAEF) was increased in patients without atrial tachyarrhythmia recurrence during follow-up. Atrial tachyarrhythmia-free survival was significantly more likely in patients without a prolonged PWD (83.5% vs 60.7%, p = 0.002). Multivariate analysis showed that LAEF and PWD were independent predictors of atrial tachyarrhythmia recurrence., Conclusions: PWD ≥ 150 ms measured after RFCA can identify patients with non-PAF at increased risk of atrial tachyarrhythmia recurrence. PWD is correlated with LVA and LAEF and reflects LA reverse remodeling., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Unlabelled: Accessory pathways (APs) that can only be ablated from the coronary sinus are likely to be located subepicardially. The electrocardiographic (ECG) and electrophysiological characteristics as well as the immediate radiofrequency ablation success rate and the recurrence rate were compared in 15 patients (11 posteroseptal and 4 left free-wall) with subepicardial APs and in 31 control patients with posteroseptal (15) and left free-wall (16) APs matched with age, sex, and AP location during the same study period in whom APs were successfully ablated from the endocardial approach. Patients with posteroseptal subepicardial APs had a longer tachycardia cycle length (355 +/- 32 vs 286 +/- 49 milliseconds, P < .05), a lower success rate (9 /11 vs 15/15, P = .09), and a higher recurrence rate (3/9 vs 0/15, P < .05) as compared with control patients. A negative delta wave with QS or QR pattern in lead II was present in all 4 patients with a manifest posteroseptal subepicardial AP located in the middle cardiac vein as compared with none of the 5 control patients with posteroseptal APs located in the proximal coronary sinus and 1 of the 9 control patients (P < .01). A positive delta wave in lead I along with an R/S of less than 1 in lead V 1 , and a negative delta wave in lead II, was noted in 1 of the 2 patients with left free-wall subepicardial APs and none of the 7 controls (P = .047). The local activation time is significantly shorter in the 4 patients with left free-wall subepicardial AP than in the 16 control patients (31 +/- 9 vs 89 +/- milliseconds, P = .044)., Conclusions: Some ECG characteristics are suggestive of APs located in the middle cardiac vein and left free-wall subepicardial site, while a longer local activation time is characteristic of left free-wall APs. The success rate is lower and the recurrence rate higher with radiofrequency ablation in patients with subepicardial AP.

We studied 196 consecutive patients with posterior paraseptal accessory pathway (AP); 124 showed manifest preexcitation and 72 were concealed AP. Successful ablation was obtained from left-sided approach in 134 patients (left posterior pasaseptal [LPS] group) and from right sided approach in 62 patients (right posterior paraseptal [RPS] group). A ventriculo-atrial (VA) interval of <50 ms recorded at LPS region (VA(LPS)) during right ventricular pacing identified 95 of the 134 patients (71%) with LPS AP with 100% specificity and positive predictive value. In the 101 patients with VA(LPS) >/=50 ms, a difference in VA interval of <20 ms recorded at the His bundle region and LPS region, DeltaVA(H-LPS), during right ventricular pacing predicted RPS AP with a sensitivity of 97%, a specificity of 85% and a positive predictive value of 91%. When these 2 parameters were used together for prediction of LPS or RPS AP, the sensitivity, specificity, and positive predictive value were 96%, 97%, and 98% for LPS AP, and 97%, 96%, and 91% for RPS AP, respectively. This simple new algorithm using VA(LPS) and DeltaVA (H-LPS) during right ventricular pacing successfully discriminates LPS and RPS AP with high sensitivity, specificity, and positive predictive value and could facilitate radiofrequency ablation in patients with posterior paraseptal AP.

This study reports new electrocardiographic (ECG) predictors of radiofrequency catheter ablation failure and recurrence in idiopathic right ventricular outflow tract (RVOT) ventricular tachycardia (VT) or ectopy based on 91 consecutive patients. Procedural success and failure rates were 85% (77/91) and 15% (14/91), respectively. Twenty three percent (18/77) had recurrence during the follow-up period of 1 to 120 months (mean 56 +/- 31 months). Baseline RVOT VT/ectopy on 12-lead ECG taken prior to ablation from 91 patients were retrospectively analyzed. Ablation performed with RVOT ectopy (isolated ectopies, bigeminy, trigeminy, or couplets) as template arrhythmia was more likely to fail (30% vs. 8%, P =.02) as opposed to RVOT VT (sustained or nonsustained). VT/ectopy-QRS morphology variation was more observed in failed ablations (36% vs. 7%, P =.001). Significantly wider mean VT/ectopy QRS in leads I, II, AVR, V2, V3, V5, and V6 were noted in failed ablation group. Mean R wave amplitude reached statistical significance only in lead II (22.0 +/- 5.1 mV for failed vs. 17.8 +/- 5.2 mV for successful outcomes; P =.009). QRS morphologic variation (47% vs. 16%; P =.009) was the only statistically significant ECG to be more common in patients with arrhythmia recurrence. In conclusion, ablation with ectopy over VT as template arrhythmia, presence of QRS morphologic variation, wider mean QRS width, and taller mean R-wave amplitude in lead II were identified ECG predictors of failed RVOT VT/Ectopy ablation. The only ECG predictor of recurrence was the presence of RVOT VT or ectopy QRS morphologic variation.

A low frequency slow potential preceding the Purkinje spike was recorded at the midseptum during tachycardia in a 69-year-old man with verapamil-sensitive left ventricular tachycardia. This potential was characteristically absent during sinus rhythm before radiofrequency ablation, but became evident following the QRS complex after successful ablation at the tachycardia exit site. Induction of tachycardia with programmed stimulation was dependent on emergence of this slow potential. Decremental conduction was noted between the QRS complex and the slow potential. Further energy application at a site proximal to where the slow potential was initially recorded totally eliminated the slow potential.

A 38-year-old man with no significant structural heart disease suffered from one episode of wide QRS tachycardia. The electrocardiogram showed a PR interval of 0.20 second and a QRS duration of 0.10 second. His bundle recording revealed an HV interval of 90-100 ms. The tachycardia was inducible with programmed stimulation and displayed a QRS morphology of complete left bundle branch block. It was characterized by an atrioventricular dissociation, a cycle length of 280 ms, and an H deflection preceding each QRS complex. Pacing from the right ventricular apex at a cycle length of 270 ms entrained the tachycardia, while at a cycle length of 260 ms, the tachycardia was terminated. Four years later, the patient presented with complete atrioventricular block with a wide QRS escape rhythm. An electrophysiologic study conducted while he was in 1:1 atrioventricular conduction showed an HV interval of 100 ms. Second-degree infrahisian block developed at an atrial paced cycle length of 700 ms. There was no induction of tachycardia with programmed stimulation before or after isoproterenol. The patient was treated with an implantation of a permanent pacemaker.