Outcomes of cavotricuspid isthmus-dependent flutter ablation: randomized study comparing single vs. multiple catheter procedures-the SIMPLE study.

BACKGROUND: Catheter ablation is recommended as first-line therapy for patients with symptomatic typical AFl. Although the conventional multi-catheter approach is the standard of care for cavotricuspid isthmus (CTI) ablation, a single-catheter approach was recently described as a feasible alternative. The present study sought to compare safety, efficacy, and efficiency of single vs. multi-catheter approach for atrial flutter (AFl) ablation. METHODS: In this randomized multi-center study, consecutive patients referred for AFl ablation (n = 253) were enrolled and randomized to multiple vs. single-catheter approach for CTI ablation. In the single-catheter arm, PR interval (PRI) on the surface ECG was used to prove CTI block. Procedural and follow-up data were collected and compared between the two arms. RESULTS: 128 and 125 patients were assigned to the single-catheter and to the multi-catheter arms, respectively. In the single-catheter arm, procedure time was significantly shorter (37 ± 25 vs. 48 ± 27 minutes, p = 0.002) and required less fluoroscopy time (430 ± 461 vs. 712 ± 628 seconds, p < 0.001) and less radiofrequency time (428 ± 316 vs. 643 ± 519 seconds, p < 0.001), achieving a higher first-pass CTI block rate (55 (45%) vs. 37 (31%), p = 0.044), compared with the multi-catheter arm. After a median follow-up of 12 months, 11 (4%) patients experienced AFl recurrences (5 (4%) in the single-catheter arm and 6 (5%) in the multi-catheter arm, p = 0.99). No differences were found in arrhythmia-free survival between arms (log-rank = 0.71). CONCLUSIONS: The single-catheter approach for typical AFl ablation is not inferior to the conventional multiple-catheter approach, reducing procedure, fluoroscopy, and radiofrequency time.

Safety and Outcomes of Ventricular Tachycardia Substrate Ablation During Sinus Rhythm: A Prospective Multicenter Registry.

OBJECTIVES: This study sought to analyze safety and outcomes of ventricular tachycardia (VT) substrate ablation during sinus rhythm (SR), without baseline VT induction. BACKGROUND: Safety and outcomes after scar-related VT ablation during SR are not well known. Hemodynamic instability and need for electrical cardioversion can compromise safety of VT ablation procedures. METHODS: Four hundred twelve consecutive patients with structural heart disease undergoing VT ablation were included in a prospective multicenter registry. Substrate ablation during SR, without baseline VT induction, was the first step of the ablation procedure and the standard protocol. Scar dechanneling was the substrate ablation technique used. VT inducibility was tested after substrate ablation. RESULTS: VT induction protocol was negative after substrate ablation in 289 patients (70.1%), completing the procedure in SR. Procedure-related complication rate was 6.5%, including 1 death (0.2%). Thirty-day mortality after first VT ablation procedure was 1.7%. Overall survival was 95.8% and 88.6% at 1 and 3 years of follow-up, respectively. In a multivariable proportional hazards regression model, age ≥70 years (hazard ratio [HR]: 4.95 [2.59 to 9.47]; p < 0.001), chronic obstructive pulmonary disease (HR: 2.37 [1.24 to 4.52]; p = 0.008), left ventricular ejection fraction <30% (HR: 2.43 [1.37 to 4.33]; p = 0.002), and incomplete substrate ablation (HR: 2.37 [1.24 to 4.52]; p = 0.026) were independent predictors of overall mortality. At 12 months' follow-up, VT-free survival was 82.5% after 1 procedure and 87.8% after n procedures CONCLUSIONS: Substrate ablation during SR avoiding multiple VT induction has low procedure-related complications and low early mortality. Age, chronic obstructive pulmonary disease, and reduced left ventricular ejection fraction, but also incomplete substrate elimination, are predictors of mortality.

Clinical validation of automatic local activation time annotation during focal premature ventricular complex ablation procedures.

Aims: Current navigation systems incorporate algorithms for automatic identification of local activation time (LAT). However, data about their utility and accuracy in premature ventricular complex (PVC) ablation procedures are scarce. This study analyses the accuracy of an algorithmic method based on automatic annotation of the maximal negative slope of the unipolar electrogram within the window demarcated by the bipolar electrogram compared with conventional manual annotation during PVC ablation procedures. Methods and results: Forty patients with successful ablation of focal PVC in three centres were included. Electroanatomical activation maps obtained with the automatic system (WF-map) were compared with manual annotation maps (M-map). Correlation and concordance of LAT obtained with both methods were assessed at 3536 points. The distance between the earliest activation site (EAS) and the effective radiofrequency application point (e-RFp) were determined in M-map and WF-map. The distance between WF-EAS and M-EAS was assessed. Successful ablation sites included left ventricular outflow tract (LVOT; 55%), right ventricular outflow tract (40%), and tricuspid annulus (5%). Good correlation was observed between the two annotation approaches (r = 0.655; P < 0.0001). Bland-Altman analysis revealed a systematic delayed detection of LAT by WF-map (bias 33.8 ± 30.9 ms), being higher in LVOT than in the right ventricle (42.6 ± 29.2 vs. 27.2 ± 30.5 ms, respectively; P < 0.0001). No difference in EAS-eRFp distance was observed between M-map and WF-map (1.8 ± 2.8 vs. 1.8 ± 3.4 mm, respectively; P = 0.986). The median (interquartile range) distance between WF-EAS and M-EAS was 2.2(0-6) mm. Conclusion: Good correlation was found between M-map and WF-map. Local activation time detection was systematically delayed in WF-map, especially in LVOT. Accurate identification of e-RFp was achieved with both annotation approaches.

Epicardial ablation of syncopal ventricular tachycardia. Utility of the electrocardiogram.

We describe the case of a young man with syncopal ventricular tachycardia, normal left ventricular ejection fraction, normal coronary arteries, and a left ventricular aneurysm. The ECG during tachycardia suggested an epicardial origin. The arrhythmia was successfully treated using a non-surgical transthoracic epicardial approach.

Use of irbesartan to maintain sinus rhythm in patients with long-lasting persistent atrial fibrillation: a prospective and randomized study.

BACKGROUND: Data from studies of angiotensin-converting enzyme inhibitors provide evidence that the renin-angiotensin-aldosterone system plays a role as a mediator of atrial remodeling in atrial fibrillation. The present study has evaluated the effect of treatment with the angiotensin I type 1 receptor blocker irbesartan on maintaining sinus rhythm after conversion from persistent atrial fibrillation. METHODS AND RESULTS: To be included in the present study, patients must have had an episode of persistent atrial fibrillation for >7 days. The patients were then randomized and scheduled for electrical cardioversion. Two groups of patients were compared: Group I was treated with amiodarone, and group II was treated with amiodarone plus irbesartan. The primary end point was the length of time to a first recurrence of atrial fibrillation. From a total of 186 patients assessed in the study, 154 were analyzed with the use of intention-to-treat analysis. Seventy-five patients were randomly allocated to group I and 79 to group II. After 2 months of follow-up in the intention-to-treat analysis, the group treated with irbesartan had fewer patients with recurrent atrial fibrillation (Kaplan-Meier analysis, 84.79% versus 63.16%, P=0.008). The Kaplan-Meier analysis of time to first recurrence during the follow-up period (median time, 254 days [range, 60 to 710]) also showed that patients treated with irbesartan had a greater probability of remaining free of atrial fibrillation (79.52% versus 55.91%, P=0.007). CONCLUSIONS: Patients treated with amiodarone plus irbesartan had a lower rate of recurrence of atrial fibrillation than did patients treated with amiodarone alone.