Perimitral Atrial Flutter Research Articles

Predictors for New-onset Atrial Fibrillation in General Population on the Special Health Checkups of National Health Insurance (TAMA MED Project-AF)

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.

Usefulness of ultra-high resolution mapping for detecting epicardial atrial activation during mitral isthmus ablation

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.

Arrhythmia recurrence in patients following cardiac surgery with concomitant therapy of atrial fibrillation – Experience of our cardiac center

IntroductionSurgical treatment of atrial fibrillation (AF) is a common and time-proven treatment method for this type of arrhythmias both as a separate procedure and as a procedure related to cardiac surgery for another indication (concomitant procedure). Patients experience arrhythmia recurrence despite highly efficient surgical treatment. These arrhythmias are often resistant to pharmacological treatment (due to an extensive fibrous substrate); therefore, electroanatomical mapping accompanying catheter ablation is significantly more effective. The arrhythmogenic fibrous substrate is a result of both a primary cardiac disease (an underlying disease causing atrial dilation) and surgical intervention (incision, cannula insertion sites, MAZE lines with a renewed spread of electrical signal in these blocks). Method and patientsElectroanatomical mapping and ablation were performed in 92 patients with arrhythmia recurrence following concomitant surgical treatment for AF between January 2010 and November 2015. The Cox maze procedure was performed using a disposable cryoablation catheter. The heart rhythm in patients following radiofrequency ablation procedure was monitored in half-year intervals (24-h Holter ECG, 7-day loop recorder, in some patients also by means of implanted pacemakers or implantable loop recorders). The average left atrial size (PLAX) was 50mm, 59% of patients underwent mitral valve surgery, 54% of patients had tricuspid valve surgery, 16% were operated for congenital developmental disorders, in 17% of patients, repeated cardiac surgery was performed. The above-mentioned facts show that these are patients with an extensive arrhythmogenic substrate. ResultsThe Cox maze procedure resulted in an extensive fibrous arrhythmogenic substrate in the atrium (arrhythmia recurrence following the maze procedure is more often regular atrial tachycardias while AF is predominant among arrhythmias for which the maze procedure was indicated). All patients had a follow-up visit after 12 months, 80% of patients presented for a follow-up visit after 24 months. Early recurrence after ablation (within 3 months following the procedure) was found in 21% of patients. Early recurrence after ablation was statistically significantly related to arrhythmia recurrence within 12 months (p=0.003) and arrhythmia recurrence within 24 months (p=0.003). 73% of patients had no recurrent AF or atrial tachycardia (AT) after 12 months and 53% after 24 months. A total of 146 arrhythmias were ablated, i.e. 1/3 of patients had more than 1 arrhythmia. These were persistent AF found in 24% of patients, paroxysmal AF seen in 13% of patients and regular AT detected in 53% of patients. More than one half of regular AT originated in LA (as perimitral atrial flutter in most cases). Remaining arrhythmias originated from the right atrium (as typical atrial flutter in half of the cases). 57% of patients had a renewed spread of signal in the mitral isthmus (ablation of the coronary sinus was necessary in 1/3 of patients). No domination in the number of reconnections was found for any of the pulmonary veins. The finding of a significantly reduced signal amplitude in the entire LA was associated with a higher risk of acute ablation failure (p=0.001). Acute ablation failure was associated with a higher risk of arrhythmia recurrence after 12 months (p=0.07). There was a trend of a higher AT incidence originating from the RA in patients who underwent surgery for a congenital heart defect (p=0.06). The diagnosis of arterial hypertension was associated with a higher risk of arrhythmia recurrence (p=0.13). The finding of persistent AF on ECG (compared to other findings, i.e. paroxysmal AF and regular AT) before ablation did not increase the risk of recurrence after ablation. ConclusionIn patients after cardiac surgery, catheterization performed to treat arrhythmia recurrence is a effective method of subsequent treatment, despite an extensive arrhythmogenic substrate. A rather large number of AT cases originate from the right atrium, in particular in patients after surgery for congenital heart defects. Patients with a significantly reduced signal in the larger part of the atrium due to an extensive arrhythmogenic substrate present the most complicated cases.

Catheter ablation of organized atrial arrhythmias in orthotopic heart transplantation

Organized atrial arrhythmias (OAAs) are common after orthotopic heart transplantation (OHT). Some controversies remain about their clinical presentation, relationship with atrial anastomosis and electrophysiologic features. The objectives of this retrospective study were to determine the mechanisms of OAAs after OHT and describe the outcomes of radiofrequency catheter ablation (RFCA). Thirty consecutive transplanted patients (mean age 48 ± 17 years, 86.6% male) underwent 3-dimensional electroanatomic mapping and RFCA of their OAA from 2004 to 2012 at our center. Twenty-two patients had biatrial anastomosis and 8 had bicaval anastomosis. Macro-reentry was the arrhythmia mechanism for 96% of patients. The electrophysiologic diagnoses were: cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) in 93% of patients (n = 28); perimitral AFL in 3% (n = 1); and focal atrial tachycardia (FAT) in 3% (n = 1). In 5 patients with biatrial anastomosis, a right FAT was inducible. Primary RFCA success was obtained in 93% of patients. Mean follow-up time was 39 ± 26.8 months. Electrical repermeation between recipient and donor atria, present in 20% of patients (n = 6), did not account for any of the OAAs observed. Survival without OAA relapse at 12, 24 and 60 months was 93%, 89% and 79%, respectively. CTI-dependent AFL accounted for most instances of OAA after OHT, regardless of anastomosis type. Time from transplantation to OAA was shorter with bicaval than with biatrial anastomosis. RFCA was safe and provided good long-term results.

1673Postablative perimitral atrial flutter. Extrapolation of arrhythmia simulation data to ablation clinical results

1673Postablative perimitral atrial flutter. Extrapolation of arrhythmia simulation data to ablation clinical results

Mitral isthmus ablation using a circular mapping catheter positioned in the left atrial appendage as a reference for conduction block.

BackgroundFor perimitral atrial flutter (PMFL) developing after catheter ablation of atrial fibrillation (AF), to create a complete conduction block at the mitral isthmus (MI) is mandatory to terminate it, however, it is still challenging.MethodsThis study consisted of 80 patients (74 male, 61 ± 8.1 years) undergoing MI ablation. After a circular mapping catheter was positioned at the neck of the left atrial appendage (LAA), the MI ablation was performed on the MI line just below the LAA neck targeting the earliest activation recording site of the LAA catheter during pacing from the coronary sinus (CS). When ablation during CS pacing was not successful, an RF delivery during LAA pacing was applied targeting the earliest activation site just below the MI line. If the endocardial approach failed, an RF application inside the CS was attempted.ResultsWith the endocardial approach, acute success was achieved in 51/80 patients (64%). Additional epicardial ablation from the CS was performed in 26/29 (90%) endocardially unsuccessful patients and conduction block at the MI was achieved in 21/26 (81%). Overall, complete conduction block at the MI was achieved in 72/80 patients (90%). At a mean follow-up of 16 ± 6 months, 20 patients (25%) had recurrence of atrial arrhythmias (AT: 12, AF: 8), and 10 (AT: 7, AF : 3) underwent a second procedure in which an LMI block line was completed in 3 (33%). PMFL was diagnosed in 6 out of 7 AT patients. No complications were observed.ConclusionsCreating linear lesions just beneath the neck of the LAA was highly successful under the guidance of a circular mapping catheter in the LAA using a steerable sheath. An RF application from the CS was needed in less than half of the cases.

Peri-mitral atrial flutter: personalized ablation strategy based on arrhythmogenic substrate.

The aim of this study is to characterize the arrhythmogenic substrate for peri-mitral atrial flutter (PMAFL), thereby determining a personalized ablation strategy to treat PMAFL. Thirty-six consecutive PMAFL patients (mean age: 63.8 ± 11.3, 23 males) underwent detailed three-dimensional electroanatomic mapping in left atrium (LA). The LA was divided into septal-anterior wall (SAW), posterior inferior wall (PIW), and mitral isthmus (MI) region, respectively. Ablation strategy was determined based on the endocardial bipolar voltage map. Based on electrophysiological substrates, 10, 17, and 9 cases were classified into iatrogenic, spontaneous, and no-substrate PMAFL, respectively. The mean voltage in SAW was significantly lower in spontaneous PMAFL (iatrogenic: 1.07 ± 0.66 mV; spontaneous: 0.65 ± 0.44 mV; no-substrate: 1.60 ± 0.53 mV, P <0.001), while iatrogenic PMAFL patients had the lowest voltage in MI (0.51 ± 0.23 mV vs. 1.55 ± 0.78 mV, 1.61 ± 0.56 mV, P <0.001). No low-voltage or slow conduction zone was found in the no-substrate PMAFL group. Fifteen spontaneous PMAFLs were successfully terminated by modified septal-anterior (9/10) or conventional anterior ablation line (6/7). Eight iatrogenic PMAFLs (8/10) were terminated by reinforcing the previous ablation areas. Cardioversion without PMAFL ablation was done in no-substrate PMAFL patients. After a median follow-up of 12 (7-39) months, two spontaneous PMAFL patients received redo procedures for recurrence due to "gap" conduction. The ablation strategy for PMAFL patients should be based on the arrhythmogenic substrate, but not the indiscriminate MI ablation. No-substrate PMAFLs during AF ablation could be monitored after cardioversion and might not need further ablation.

Performing the Left Atrial Maze Ablation Pattern Without Atriotomy

The need to perform an additional atriotomy is a major concern that keeps many surgeons from performing anextended left atrial lesion set in patients with atrial fibrillation during procedures such as aortic valve replacement. This does result either in a suboptimal lesion set or even in ignoring the rhythm disorder, leaving the patient exposed to an increased risk of stroke andpossible hemodynamic compromises. This report describes a technique how pulmonary vein isolation, an isolation of the posterior left atrial wall and an anterior mitral annular line, which substitutes for the mitral isthmus line in order to prevent perimitral atrial flutter, can be performed during aortic valve replacement without the need for an atriotomy. This technique allows for an optimal time management by minimizing additional cardiopulmonary bypass-time and cross-clamp-time; however, its equivalent efficacy in successfully treating atrial fibrillation compared to the left atrial Maze IV ablation pattern needs to be revealed in future trials.

Termination of Persistent Perimitral Atrial Flutter by Selective Contrast Injection Into the Vein of Marshall

A 60-year-old male patient with a 15-year history of paroxysmal atrial fibrillation, pacemaker implantation for sinus bradycardia, and cavotricuspid isthmus ablation for typical atrial flutter underwent pulmonary vein isolation. One month after the procedure, he developed perimitral atrial flutter (

高位右房中隔での焼灼により根治し得たperi-mitral atrialflutterの 1例

高位右房中隔での焼灼により根治し得たperi-mitral atrialflutterの 1例

Ablation of perimitral flutter: acute and long-term success of the modified anterior line.

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. 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. 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.

Approximation of mathematical scanning simulation data and clinical results f radiofrequency ablation of perimitral atrial flutter. Condition of existence of perimitral atrial flutter

1) to create Perimitral Atrial Flutter (PMAFL) model and estimate theoretical probability of elimination of perimital reetntry using left atrial geometry two-dimensional mathematical modeling and ablative formatting; 2) to compare clinical results of PMAFL ablation by means of mitral vs inferioseptal isthmus ablation and mathematical modeling data. Clinical phase. Study was conducted on 24 pts (6 women, 57.1 ± 9.3 years) with PMAFL. Initially RF-lesions delivered in LA in the MI (endocardial approach to MI). Distal CS roof ablation (epicardial approach to MI) was a second step. As a third step linear RF-lessions of the inferioseptal isthmus (ISI)- from right pulmonary vein ostium to mitral annulus was performed (endocardial approach to ISI). As a fourth step RF-applications applied inside the proximal CS roof (epicardial approach to ISI). Mathematical phase. As the first step numeric reconstruction of the autowave process in excitable tissues of the left atrium was performed. Fitzhugh-Nagumo equation was used for simulation to enabled us to take into account the electrical inhomogeneity of the atria (pulmonary vein ostia). A special scanning method was used for calculating characteristics of autowave processes in a two-dimensional mathematical model of the atrium. As the second step simulation of linear ablation formatting which linked PV ostia and active medium boundaries (corresponding to mitral and inferioseptal isthmus ablation lines) was performed. Clinical phase. Left MI endocardial RFA terminated PMAFL in 6 cases, increased CL without changes of atrial hierarchy activation in 2 cases, and transformed PMAFL to AFib in 2 cases. Distal CS ablation terminated PMAFL in 2 pts. Endocardial ISI ablation of associated with SR restoration in 2 cases and increasing of PMAFL CL in 5 cases. Proximal CS-roof ablation terminated PMAFL in 12 pts. Follow up was 26.7 ± 12.4 mos. Endocardial and epicardial MI approach terminated PMAFL in 8 pts (36%). RFA of endocardial 39nd epicardial aspects of the ISI restored SR in 12 pts (64%) (p< 0.05). MATHEMATICAL PHASE: There are three definite conditions of PMAFL existing: 1) Initial autowave spreading between superior PV and boundary of medium (corresponding to patent conduction between superior PV ostia and mitral annulus); 2) Non-active medium existing between four PV ostia (corresponding to PV isolation after index ablation); 3) Refractory characteristics of medium (corresponding to posterior wall of LA) and medium between PV ostia and boundaries (corresponding to isthmus zones) have to differ each other. The linear ablation patterns (from PV ostia to boundary of medium) suppress PAMFL in two-dimensional mathematical modeling of the left atrium. There are definite conditions of PAMFL simulation by means autowave processing in a 2-D active medium using scanning algorithm. Those conditions may consistent with certain EP characteristics of LA after index ablation clinical results of PAMFL ablation.

Aortic radiofrequency application as a last resort for perimitral atrial flutter ablation

Aortic radiofrequency application as a last resort for perimitral atrial flutter ablation

Termination of peri-mitral atrial flutter involving coronary sinus by single extrastimulus with non-global atrial capture

A 62-year-old man with dilated cardiomyopathy was admitted for catheter ablation of recurrent uncommon atrial tachycardia (AT). The baseline tachycardia cycle length was 260 ms. Counter-clockwise peri-mitral atrial flutter (PMAFL) involving the coronary sinus (CS) was diagnosed using entrainment and three-dimensional electroanatomical …

Coronary Sinus Activation Pattern in the Differential Diagnosis of Regular Atrial Tachyarrhythmias During Catheter Ablation of Atrial Fibrillation

Prompt diagnosis and management of atrial tachyarrhythmias (ATAs) during catheter ablation of atrial fibrillation (AF) is still challenging. In 88 patients undergoing catheter ablation of AF, 128 regular ATAs were induced or converted from AF. The coronary sinus activation time (CSAT) around the mitral annulus (MA) was measured as the difference in activation time between the most proximal and distal poles of the coronary sinus (CS) electrodes. Entrainment pacing was performed around the MA, roof area, or cavotricuspid isthmus (CTI) depending on the CSAT result. Mechanisms of tachycardias included macro-reentry around the MA (perimitral atrial flutter [PM-AFL], n=63), roof-dependent AFL (Roof-AFL, n=14), CTI-dependent AFL (CTI-AFL, n=25), and atrial tachycardia (AT, n=26). When the CSAT was ≥ 45 ms, the MA activation sequence was sequential, either proximal to distal or distal to proximal. When the CSAT was <45 ms, the MA activation sequence was mainly non-sequential with converging or diverging patterns. CSAT <45 ms was highly sensitive in ruling out PM-AFL from other left ATAs. When combined with PPI data from the MA, roof area or CTI, PM-, Roof-, CTI-AFL and AT was successfully differentiated with a high predictive accuracy. A diagnostic algorithm combining CSAT and entrainment pacing is helpful to assess the mechanism of ATAs during catheter ablation of AF.

Localized reentrant tachycardia in the aorta contiguity region mimicking perimitral atrial flutter in the context of atrial fibrillation ablation

We describe a case with a focal atrial tachycardia (AT) masquerading as perimitral atrial flutter revealed after circumferential pulmonary vein antral isolation for atrial fibrillation. It was successfully terminated and became noninducible by a point ablation on the left atrial anterior wall (LAAW) near the mitral annulus in contact with the aortic root and on the left superior pulmonary vein-left atrial appendage ridge, without any linear ablation, using electroanatomical mapping and conventional precise mapping with a maximum amplified gain within the low-voltage area. The AT revealed in our case was an LAAW-aorta contiguity area-related AT.

Mitral Isthmus Block in a Case of Persistent Left Superior Vena Cava

Persistent left superior vena cava (LSVC), an uncommon venous anomaly, could be an arrhythmogenic source of atrial fibrillation. Multiple electrical connections were reported between the LSVC and the left atrium, which may negatively impact the achievement of conduction block during linear ablation of left mitral isthmus. We describe a case with perimitral atrial flutter (AFL) in a patient with isolated LSVC. AFL was successfully treated and complete perimitral conduction block was achieved following a lengthy epicardial radiofrequency application.

The Necessity of Mitral Valve Isthmus Blockline for Peri-Mitral Atrial Flutter

Peri-mitral atrial flutter (PMFL) is occasionally encountered in patients of ablation. We evaluated the necessity of mitral valve isthmus blockline for peri-mitral atrial flutter. From January 2009 to May 2011, seventeen consecutive patients (12 males, age 56±8.3) with PMFL were included in this study. Of the 17 parents, 12 patients had no other heart disease, 2 patients had angina pectoris (1 post PCI, 1 post CABG), 1 patient had a history of open heart surgery (MVP, TAP and Maze), 2 had the other heart disease. Previously 10 parents underwent ablation for pulmonary vein isolation (PVI), 7 parents had no history of PVI. On the seventeen parents with PMFL, 12 (70%, 12/17) parents were performed ablation for PMFL. The mitral valve isthmus blockline was achieved in 58% (7/12), and required ablation into coronary sinus (CS) was 71% (5/7). All patients achieve termination of tachycardia during the ablation. As us follow-up of 13±8.1 months, there were no recurrence of PMFL at all parents (17/17). We suggested that we can finish ablation for PMFL at the termination of tachycardia as the endpoint of ablation. And we considered ablation into CS when the tachycardia couldn’t terminated by only operating intra left-atrial ablation.

Catheter Ablation for Peri-Mitral Atrial Flutter Post Mitral Valve Replacement

Peri-mitral atrial flutter (PMFL) may occur in patients with prior mitral valve replacement (MVR). Catheter ablation (CA) may be challenging owing to prosthetic valve and the surrounding scar. A 61 year-old man underwent MVR and LA maze procedure in 2005. He was admitted to our hospital in 2011 because of atrial flutter (AFL). CA for AFL was performed. In EPS findings, PV-LA connections were isolated by prior maze procedure. CARTO mapping during tachycardia (CL=290 msec), and revealed PMFL. Radiofrequency application with an irrigated-tip catheter using Agilis sheath at the mitral isthmus successfully eliminated this tachycardia. We confirmed the MI block line by the sequence of CS activation while pacing from the LAA, but the MI block line was incomplete. The activation map on the CARTO system during LAA pacing revealed early activation site with a fractionated potential near the MI (LAA pacing site to ABL distal pole interval was 80 ms). The bidirectional conduction block line was created in the MI by additional RF current application at this conduction gap. The interval from the LAA pacing site to CS distal pole prolonged from 130 msec to 230 msec. This case report highlights the rare case of successful CA for PMFL in a patient with prior MVR.

Atrial Tachyarrhythmias Concomitant with Perimitral Atrial Flutter during Catheter Ablation

Background: We report 3 cases demonstrating transition from perimitral atrial flutter to a different atrial tachycardia/flutter (AT/AFL) during linear ablation between the left pulmonary vein (PV) and the mitral annulus (mitral isthmus ablation). Methods: N/A. Results: A 67-year-old man with prior pulmonary vein isolation (PVI) underwent RFCA for recurrent AFL. Electrophysiological study (EPS) initially revealed clockwise perimitral AFL. During mitral isthmus ablation, the AFL changed into a focal AT from left atrial (LA) inferior wall with change in cycle length (CL) from 230 ms to 310 ms, which was successfully ablated at the earliest atrial activation site. A 70-year-old woman with prior mitral valve replacement and atrial fibrillation (AF) underwent RFCA for persistent AFL. EPS revealed clockwise perimitral AFL (CL=270 ms). During mitral isthmus ablation, the AFL changed into common AFL without change in CL, thus the two AFLs formed a dual-loop reentry circuit over both atria. A 65-year-old woman with prior PVI underwent RFCA for recurrent AFL. EPS revealed counterclockwise perimitral AFL. During mitral isthmus ablation, the AFL changed into a LA roof dependent AFL with change in CL from 205 ms to 250 ms, which was successfully terminated by LA roof linear ablation. Conclusion: Perimitral AFL can occur simultaneously with another AT/AFL, which becomes apparent with termination of perimitral AFL.