Search

The benefit of an anterior mitral line (AML) in patients with persistent atrial fibrillation (AF) and anterior atrial scar undergoing ablation has never been investigated. The purpose of this study was to evaluate the outcomes of AML in addition to standard treatment compared to standard treatment alone (no AML) in this subset of patients. Patients with persistent AF and anterior low-voltage zone (LVZ) treated with AML in 3 centers were retrospectively enrolled. The patients were matched in 1:1 fashion with patients having persistent AF and anterior LVZ who underwent conventional ablation in the same centers. Matching parameters were age, LVZ burden, and repeated ablation. Primary endpoint was AF/atrial tachycardia (AT) recurrence. One hundred eight-six patients (age 66 ± 9 years; 34% women) were selected and divided into 2 matched groups. Bidirectional conduction block was achieved in 95% of AML. After median follow-up of 2 years, AF/AT recurrence occurred in 29% of the patients in the AML group vs 48% in the no AML group (log-rank P =.024). On Cox regression multivariate analysis, left atrial volume (hazard ratio [HR] 1.03; P =.006) and AML (HR 0.46; P =.003) were significantly associated with the primary endpoint. On univariate logistic regression, lower body mass index, older age, extensive anterior LVZ, and position of the left atrial activation breakthrough away from the AML were associated with first-pass AML block. In this retrospective matched analysis of patients with persistent AF and anterior scar, AML in addition to standard treatment was associated with improved AF/AT-free survival compared to standard treatment alone. [Display omitted] [ABSTRACT FROM AUTHOR]

Background Perimitral flutter (PMF) is a macro-reentrant tachycardia, and mitral isthmus (MI) linear ablation is considered to be the preferable mode of treatment. Additionally, PMF can sometimes develop via epicardial connections, including coronary sinus and vein of Marshall. However, there are no reports of three-dimensional (3D) atrial tachycardia (AT) via the intramural tissue. Case summary A 78-year-old man underwent catheter ablation for paroxysmal atrial fibrillation and AT, including pulmonary vein isolation, left atrial posterior wall isolation, superior vena cava isolation, and MI linear ablation in a total of four procedures. However, AT reoccurred, and he underwent a 5th procedure for AT. Although the MI block line was complete in both the endocardial and epicardial voltage maps, AT indicated PMF. The total activation time did not cover all phases of tachycardia cycle length due to the conduction pathway through the intramural muscle/bundles that could not be mapped with the addition of epicardial mapping. The tachycardia was terminated by ablation at the mitral valve annulus in the 2 o'clock position, where the bundles might have been attached. Discussion Both endocardial and epicardial activation maps indicated 3D-PMF, whose circuit included the intramural muscle and bundles in a tachycardia circuit. It is necessary to recognize AT, which is involved via intramural tissues. [ABSTRACT FROM AUTHOR]

Catheter ablation for persistent atrial fibrillation (PeAF) is particularly challenging, as the clinical outcomes are modest. Pulmonary vein isolation (PVI) plus linear ablation is one of the main strategies for PeAF ablation. Completely durable transmural lesions are difficult to achieve by catheter ablation during mitral isthmus ablation. The ligament of Marshall contains the vein of Marshall (VOM), myocardial tracts and innervation, and serves as arrhythmogenic foci that make it an attractive target in catheter ablation of atrial fibrillation. Additionally, it co-localizes with the mitral isthmus, and may serve as a part of the perimitral isthmus reentrant circuit. Ethanol infusion into the VOM results in rapid ablation of the neighboring myocardium and its innervation. Its incorporation into PVI significantly increases the success rate of mitral isthmus block and the clinical outcome of PeAF ablation.

Mapping and ablation of perimitral flutter, a macro-reentrant tachycardia, can be sometimes challenging. We describe a case of perimitral atrial flutter following the pulmonary vein isolation in which mitral isthmus ablation failed to terminate the arrhythmia due to epicardial-endocardial breakthrough via the muscle fibers of coronary sinus. Ultra-high-definition mapping system was utilized to locate the epicardial bridge, and spot ablation of the lesion subsequently terminated the arrhythmia. [ABSTRACT FROM AUTHOR]

Background: Epicardiac conduction via the vein of Marshall (VOM) can bypass the mitral isthmus (MI) line, making MI ablation difficult. This study aimed to assess the contribution of the VOM in achieving MI conduction block. Methods: This study included 143 consecutive patients with nonparoxysmal atrial fibrillation who underwent initial MI ablation. They were retrospectively classified into two groups, a VOM‐guided group (n = 28) and a conventional group (n = 115), according to the use of a 2‐Fr electrode catheter inserted in the VOM. The acute success rate of achieving MI block and the ablation data were assessed. When the bidirectional block was verified exclusively in the VOM or coronary sinus (CS) electrodes, we defined it as a pseudo MI block. In the VOM‐guided group, we ascertained the complete MI block, verified both in the VOM and CS electrodes. Results: In the VOM‐guided group, the pseudoblock was observed in 33.3% of the patients during MI ablation. With significantly less radiofrequency energy (19 322.6 ± 11 352.8 vs 25 389.3 ± 19 951.9, P = 0.04), we achieved a similar level of success rate in MI ablation in the VOM‐guided group (96.4% vs 91.3%, P = 0.36). Notably, after achieving complete MI block, atrial burst pacing induced two perimitral flutters in the VOM‐guided group, which were successfully terminated by the additional radiofrequency application. Conclusions: Assessment of electrical conduction through the VOM could clarify the existence of a pseudo MI conduction block. However, the existence of a slow conduction through the MI could be detected only after induction of perimitral atrial tachycardia with atrial programmed stimulation. [ABSTRACT FROM AUTHOR]

Background: Left atrial flutter following atrial fibrillation (AF) ablation is increasingly common and difficult to treat. We evaluated the safety and efficacy of ablation of the anteroseptal line connecting the right superior pulmonary vein (RSPV) to the anteroseptal mitral annulus (MA) for the treatment of perimitral flutter (PMF). Methods: We systematically studied patients who were previously treated with AF ablation and who presented to the electrophysiology laboratory with atrial tachyarrhythmias between January 2000 and July 2010. The diagnosis of PMF was confirmed by activation mapping and/or entrainment. After re-isolation of any recovered pulmonary vein, a linear radiofrequency (RF) ablation was performed on the line that connected the RSPV to the anteroseptal MA. In this analysis, we included only patients who were treated with an anteroseptal line for their PMF. Results: Ablation was performed at the anteroseptal line in 27 PMF patients (63±13 years; 9 women) who had undergone prior ablation for paroxysmal (n=3) or persistent (n=24) AF, using electroanatomic activation mapping (70% CARTO, 30% NavX). The anteroseptal ablation line was effective in 22/27 (81.5%) patients in the acute-care setting. Termination of AF to sinus rhythm occurred in 15/22 (68.2%) patients, and 7/22 (31.8%) patients׳ AF converted to another right or left atrial flutter. At the 6-month follow-up, 20% of patients demonstrated recurrent left atrial tachyarrhythmia. Only one patient required repeat ablation, and the remaining patients׳ condition was controlled with antiarrhythmic medications. No major procedural complications or heart block occurred. Conclusion: Ablation at the left atrial anteroseptal line is safe and efficacious for the treatment of PMF. Unlike ablation at the traditional mitral isthmus line, ablation at the left atrial anteroseptal line does not require ablation in the coronary sinus.

Background: Differential pacing technique to confirm mitral isthmus (MI) block is sometimes challenging due to destroyed tissues after extensive ablation. The purpose of this study is to set an endpoint of MI ablation using conduction time around the mitral annulus (MA). Methods: Forty‐five consecutive patients with persistent atrial fibrillation who received MI linear ablation were included. The geometry and activation times of the left atrium around the MA were collected using a multipolar catheter before ablation. During coronary sinus (CS) pacing, the time between the stimulus and the wave‐front collision at the opposite side of the MA (defined as T/2) was calculated, and the doubled value was defined as the estimated perimitral conduction time (E‐PMCT). The endpoint for complete MI block was when the stimulus (at distal CS) minus the maximal delayed potential (St−MDP) on the MI interval reached the E‐PMCT. Results:St−MDP reached E‐PMCT during MI ablation in 44/45 patients. Among these 44 patients, differential pacing revealed bidirectional block in 39/44 (88.6%), whereas in 5/44 (11.4%), the differential pacing was not possible because of the loss of capture of local potentials due to extensive applications around the linear line. In one patient, the St−MDP did not reach E‐PMCT (E‐PMCT: 148 ms, St−MDP :130 ms) and differential pacing revealed no MI block. E‐PMCT values (median 176 ms) correlated strongly with St−MDP (median 185 ms, P < 0.0001, R = 0.98). Conclusions: Although E‐PMCT differs between individuals, the value is significantly correlated with the St−MDP. This technique may be useful in providing an individual endpoint of MI ablation as an alternative to differential pacing. [ABSTRACT FROM AUTHOR]

The ligament of Marshall is an embryological remnant of the left superior vena cava that contains neural tissues shown to be an arrhythmogenic source of atrial fibrillation (AF). Vein of Marshall (VOM) ethanol ablation is an ablation technique that can potentially treat AF by targeting the ligament of Marshall. We report a case of a patient who developed a pro-arrhythmic effect related to VOM ethanol ablation, which manifested as a perimitral flutter., Competing Interests: The authors report no conflicts of interest for the published content. No funding information was provided., (Copyright: © 2023 Innovations in Cardiac Rhythm Management.)

Competing Interests: There is no conflict of interest declared by all the authors.

Aims: The success of mitral isthmus (MI) ablation has been related to CT scan defined MI anatomy. We sought to correlate electroanatomical MI characteristics with MI ablation success in patients with perimitral flutter (PMF). Methods and Results: In 53 consecutive patients (46 males, 61 ± 10 years) with PMF, MI was ablated with endocardial ± coronary sinus (CS) linear radiofrequency (RF) ablation lesion. Acute (termination of PMF during ablation) and long-term procedural success were studied. Mitral isthmus characteristics (thickness--minimal endocardial to CS distance, length, maximal MI bipolar voltage), as well as MI ablation line length and width, RF duration, and delivered energy were analysed. In 43 of the 53 patients (81%), acute success was observed. This was more frequently achieved in patients with thinner MI (2.4 ± 3.1 vs. 7 ± 3.2 mm; P = 0.0009). Mitral isthmus thickness predicted ablation failure with a ROC area of 0.84. The best threshold to predict MI ablation failure was 8.3 mm with a sensitivity of 67% and a specificity of 97%. Left atrial size was of greater importance in failed cases (2D echo surface: 24.1 ± 2.5 vs. 32.5 ± 6.9 cm2, P = 0.005; electroanatomic volume: 124 ± 32 vs. 165 ± 23 mL, P = 0.02). None of the other electroanatomical characteristics were associated with outcome. After a mean follow-up of 28 ± 15 months, 21 patients (39%) had atrial fibrillation (AF) or atypical flutter (PMF recurrence in four). Conclusion: Smaller MI thickness is associated with acute success in PMF ablation. Mitral isthmus electroanatomical characteristics might be used for decision-making on strategy during persistent AF ablation and for selecting the best location for interrupting PMF. [ABSTRACT FROM AUTHOR]

Background Left atrial flutter following atrial fibrillation (AF) ablation is increasingly common and difficult to treat. We evaluated the safety and efficacy of ablation of the anteroseptal line connecting the right superior pulmonary vein (RSPV) to the anteroseptal mitral annulus (MA) for the treatment of perimitral flutter (PMF). Methods We systematically studied patients who were previously treated with AF ablation and who presented to the electrophysiology laboratory with atrial tachyarrhythmias between January 2000 and July 2010. The diagnosis of PMF was confirmed by activation mapping and/or entrainment. After re-isolation of any recovered pulmonary vein, a linear radiofrequency (RF) ablation was performed on the line that connected the RSPV to the anteroseptal MA. In this analysis, we included only patients who were treated with an anteroseptal line for their PMF. Results Ablation was performed at the anteroseptal line in 27 PMF patients (63±13 years; 9 women) who had undergone prior ablation for paroxysmal ( n =3) or persistent ( n =24) AF, using electroanatomic activation mapping (70% CARTO, 30% NavX). The anteroseptal ablation line was effective in 22/27 (81.5%) patients in the acute-care setting. Termination of AF to sinus rhythm occurred in 15/22 (68.2%) patients, and 7/22 (31.8%) patients׳ AF converted to another right or left atrial flutter. At the 6-month follow-up, 20% of patients demonstrated recurrent left atrial tachyarrhythmia. Only one patient required repeat ablation, and the remaining patients׳ condition was controlled with antiarrhythmic medications. No major procedural complications or heart block occurred. Conclusion Ablation at the left atrial anteroseptal line is safe and efficacious for the treatment of PMF. Unlike ablation at the traditional mitral isthmus line, ablation at the left atrial anteroseptal line does not require ablation in the coronary sinus. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation of left atrial linear lesions is an effective treatment option for perimitral flutter and is often used as a substrate modification approach for persistent atrial fibrillation. The two most popular mitral isthmus lines are those of the anterior or the posterior mitral isthmus. A comparison of these two mitral isthmus ablation approaches is still pending.Methods: Patients undergoing catheter ablation either at the anterior or the posterior mitral isthmus were included. Procedural success, conduction block, procedure durations, complications, and the necessity of a coronary sinus ablation were analyzed.Results: We investigated 80 consecutive patients, 40 (50%) with an anterior and 40 (50%) with a posterior mitral isthmus line. Twenty (25.0%) patients had perimitral annulus flutter; the remainder of the patients had persistent atrial fibrillation. Bidirectional conduction block was achieved in the same proportion in the anterior group (36; 90.0%) as it was in the posterior group (30; 75.0%) (statistically insignificant). Duration of procedure (18 ± 12 vs. 34 ± 24 min, p = 0.001), radiofrequency application (11 ± 7 vs. 18 ± 11 min, p = 0.004), and fluoroscopy (2 ± 2 vs. 8 ± 8 min, p < 0.001) values were all significantly lower in the anterior group. Only patients in the posterior line group had to be ablated via the coronary sinus 24 (60.0 %).Conclusions: Ablation at the anterior mitral isthmus shows the same success rate as the posterior mitral isthmus does. Catheter ablation at the anterior mitral isthmus is associated with significantly shorter procedure durations without the need of a coronary sinus ablation. [ABSTRACT FROM AUTHOR]

Background: Mitral isthmus is often targeted as a part of stepwise approach during radiofrequency ablation for persistent atrial ablation. Acute success rate in achieving the mitral isthmus block is only modest, late reconduction rate is relatively high and, consequently, incomplete lesion may be proarrhythmic. We describe the first-in-man experience with successful MI ablation by bipolar RF energy delivery.Case Presentation: A 64-year-old caucasian man after two previous ablation procedures for drug resistant atrial fibrillation in recent four years, which included pulmonary vein isolation and linear left atrial lesions, was referred for the treatment of recurrent perimitral flutter. Despite the third attempt to create bidirectional block at the mitral isthmus region, we were not even able to stop the arrhythmia by aggressive unipolar radiofrequency ablation both from the left atrium and coronary sinus, because of deeply embedded slow conducting channel probably around the vein of Marshall. Arrhythmia was finally terminated and the block was achieved by bipolar radiofrequency ablation between two irrigated-tip catheters positioned at the left atrial endocardium and contralaterally inside the coronary sinus.Conclusion: Bipolar radiofrequency energy delivery can be an option for ablation of perimitral flutter resistant to standard unipolar radiofrequency ablation. This may improve clinical outcome of patients undergoing non-pharmacological treatment for persistent atrial fibrillation. The safety and efficacy of this technique has to be confirmed in future studies. [ABSTRACT FROM AUTHOR]

We describe a patient with perimitral atrial flutter (PMF) following the atrial fibrillation ablation and the linear ablation at the mitral isthmus (MI). From both the activation and the voltage maps using ultra-high resolution mapping, we detected the epicardial connection through the coronary sinus (CS) within the entire reentrant circuit. Point ablation within the CS, not additional linear MI ablation from the endocardium terminates PMF, with a bidirectional block across the low voltage area at the MI. [ABSTRACT FROM AUTHOR]

Aims The modified anterior line (MAL) is an alternative to the mitral isthmus (MI) line for the treatment of perimitral atrial flutter (PMFL). We sought to investigate acute and long-term efficacy of this line if routinely used for PMFL. Methods and results The cohort included 77 consecutive patients who underwent catheter ablation of PMFL. The anterior line was deployed between the anterolateral mitral annulus and the ostium of the left superior pulmonary vein. Perimitral atrial flutter was either the presenting arrhythmia after persistent atrial fibrillation (AF) ablation (Group 1, n = 42, 54.5%), occurring during AF ablation (Group 2, n = 25, 35%) or presenting as primary arrhythmia (Group 3, n = 8, 10%). Acute success was defined as PMFL termination during MAL deployment with demonstration of bidirectional line block. Acute success was achieved in 68 of 77 patients (88%) without difference between the three groups. In five patients an additional MI line was necessary to terminate PMFL and in four patients both lines failed to achieve termination. During follow-up (16 ± 7 months), 38 of 77 (49%) patients underwent a repeat procedure for a recurrent arrhythmia. During reablation, 13 of 38 (34%) patients were identified to have a PMFL recurrence. Persistent MAL block was demonstrated in 22 of 38 (58%) patients during the repeat ablation. Conclusion The MAL is effective for acute and long-term treatment of PMFL. Maintenance of bidirectional MAL block was shown in 58% of patients during a repeat ablation. [ABSTRACT FROM PUBLISHER]

Background: Perimitral flutter (PMF) is a common form of left atrial tachycardia after atrial fibrillation (AF) ablation. The mitral isthmus (MI) is the standard ablation target. However, in some cases bidirectional block cannot be achieved. Objective: The purpose of this study was to describe the first experience using a transthoracic epicardial (TTE) approach to treat recurrent PMF after prior unsuccessful ablation. Methods: This is a case series of four patients with recurrence of highly symptomatic drug-refractory PMF (all male, median age 55 years, 3/4 hypertensive, 2/4 persistent AF, median AF period 24 months). Three patients presented with PMF-related tachymyocardiopathy. TTE ablation of MI was performed after a median of two prior endocardial MI and coronary sinus ablation attempts, using an open-tip 3.5-mm irrigated catheter (40 W, 45ºC). Persistent bidirectional block was assessed by activation mapping and differential pacing and was achieved in all patients. Results: No PMF recurrence was observed after median follow-up of 18 months (range 15–22 months; two patients without antiarrhythmic drugs and two with previously ineffective amiodarone). Left ventricular function normalized in all three patients with tachycardiomyopathy. There were no complications related to TTE approach. Conclusion: The present study is the first to report the feasibility of a TTE approach for highly symptomatic PMF refractory to endocardial and coronary sinus MI ablation. [Copyright &y& Elsevier]

Background: Treatment of perimitral flutter (PMF) requires bidirectional mitral isthmus (MI) block, which can be difficult with radiofrequency ablation (RFA). The vein of Marshall (VOM) is located within the MI. Objective: To test whether VOM ethanol infusion could help achieve MI block. Methods: Perimitral conduction was studied in patients undergoing ablation of atrial fibrillation. Group 1 included 50 patients with a previous atrial fibrillation ablation undergoing repeat ablation, 30 of whom had had MI ablation. Spontaneous (8 of 50) or inducible PMF (21 of 50) was confirmed by activation mapping. Group 2 included 21 patients undergoing de novo VOM ethanol infusion. The VOM was cannulated with a quadripolar catheter for pacing and with an angioplasty balloon to deliver up to four 1-mL infusions of 98% ethanol. Voltage maps were created before and after VOM ethanol infusion. Bidirectional MI block was verified by differential pacing. RFA times required to achieve it were assessed. Results: In group 1, VOM ethanol infusion acutely terminated PMF in 5 of 29 patients. RFA needed to achieve bidirectional MI block was 2.2 ± 1.6 minutes. Presence of PMF or previous MI ablation did not affect RFA times. In group 2, RFA needed to achieve bidirectional MI block was 2.0 ± 1.6 minutes (P = NS). Five patients had bidirectional MI block achieved solely by VOM ethanol infusion without RFA. In both groups, ablation after VOM ethanol infusion was required in the annular aspect of the MI. There were no acute complications. Conclusion: VOM ethanol infusion is useful in the treatment of PMF and assists in reliably achieving bidirectional MI block. [Copyright &y& Elsevier]

Vein of Marshall Ethanol in Recurrent AF. Introduction: Atrial fibrillation (AF) or flutter can recur after pulmonary vein (PV) antral isolation (PVAI). The vein of Marshall (VOM) has been linked to the genesis of AF. We hypothesized that the VOM may play a role in AF recurrences and that VOM ethanol infusion may have therapeutic value in this setting. Methods and Results: Sixty-one patients with recurrent AF or flutter after PVAI were studied. The VOM was successfully cannulated in 54; VOM and PV electrograms were recorded, and differential PV-VOM pacing was performed. VOM signals were present in all patients; however, VOM triggers of AF could not be demonstrated. VOM tachycardia was present in 1 patient. Left inferior (LIPV) and left superior (LSPV) reconnection was present in 32 and 30 patients, respectively. Differential pacing in VOM and LIPV showed VOM-mediated LIPV reconnection in 5/32 patients. In others, VOM and PV connected indirectly via left atrial tissues. Up to four 1 cc infusions of 98% ethanol were delivered in the VOM. Regardless of the reconnection pattern, ethanol infusion eliminated LIPV and LSPV reconnection in 23/32 and 13/30 patients, respectively. Ethanol terminated VOM and LIPV tachycardias in 2 patients. There were no acute procedural complications. Conclusions: VOM signals are consistently present in recurrent AF. VOM may rarely play a role in PV reconnection. However, VOM ethanol infusion can be useful in patients with recurrent AF after PVAI, assisting in achieving redisconnection of reconnected left PVs. (J Cardiovasc Electrophysiol, Vol. 23, pp. 583-591, June 2012) [ABSTRACT FROM AUTHOR]

The article presents a case study in which a 63-year-old woman with no history of left atrial surgery or catheter ablation has a persistent, drug-refractory atrial tachyarrhythmia (ATA) and notes the electrocardiogram showed waves inconsistent with atrial flutter (AFL). The article asks for a diagnosis of the ATA and also for the origin of the double coronary sinus (CS) potentials which occurred during ATA.