Cavotricuspid Isthmus-dependent Atrial Flutter Research Articles

Atrial fibrillation inducibility during cavotricuspid isthmus-dependent atrial flutter ablation as a predictor of clinical atrial fibrillation. A meta-analysis.

Atrial fibrillation (AF) and cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) are two separate entities that coexist in a significant percentage of patients. We sought to investigate whether AF inducibility during CTI AFL ablation predicted the occurrence of AF at follow-up after successful AFL ablation. A systemic review of Medline, Cochrane, and Embase was done for all the clinical studies in which assessment of AF inducibility in patients undergoing ablation for CTI AFL was performed. Given the low heterogeneity (i.e., I 2 <25), we used a fixed effect model for our analysis. A total of 10 studies (4 prospective and 6 retrospective) with a total of 1299 patients (male, 73%; mean age 59 ± 11years) fulfilled the inclusion criteria. During a mean follow-up period of 23 ± 7.6months, 407 patients (31%) developed AF during AFL ablation. The overall incidence for new-onset AF during follow-up was 29% (47% in the group with inducible AF vs. 21% in the non-inducible group). The odds ratio (OR) for developing AF after AFL ablation in patients with AF inducibility for all studies combined was 3.72, 95% CI 2.83-4.89 [prospective studies (OR 5.52, 95% CI 3.23-9.41) vs. retrospective studies (OR 3.23, 95% CI 2.35-4.45)]. Although ablation for CTI AFL is highly effective, AF continues to be a long-term risk for individuals undergoing this procedure. AF induced by pacing protocols in patients undergoing CTI AFL predicts for future AF. Inducible AF is a clinically relevant finding that may help guide decisions for long-term anticoagulation after successful typical AFL ablation especially in patients with elevated CHADS-VASc scores (≥2) and in considering prophylactic PVI during CTI AFL ablation.

Routine use of intracardiac echocardiography for atrial flutter ablation is associated with reduced fluoroscopy time, but not with a reduction of radiofrequency energy delivery time.

The ablation of cavotricuspid-isthmus (CTI) atrial flutter (AFL) dependent atrial flutter could be difficult in patients with complex anatomy of the CTI.The aim of the study was to assess whether the use of intracardiac echocardiography (ICE) was associated with less fluoroscopy time and faster ablations of cavotricuspid isthmus dependent atrial flutter (CTI-AFL). Patients with an indication for an ablation of a CTI-AFL were enrolled. Patients in which ablation of a CTI-AFLas part of an atrial fibrillation ablation were not included. Randomization was done using the envelope method. Standard techniques (i.e., coronary sinus, 20-polar halo catheter, and an ablation catheter), and criteria of success (bidirectional block through the CTI) were used. In patients randomized to the ablation with ICE, a 10F AcuNav ICE probe (Siemens, Germany)was used. Seventy-nine patients were enrolled; 40 were randomized to ablation with ICE and 39 without ICE. The X-ray exposure was shorter (3.29±2.6 vs. 5.94±3.43 min, p<0.001) and total X-ray dose was reduced (3.30±1.98 vs. 6.68±5.25 Gy.cm2, p<0.001) in the ICE group. However, the total RF energy ablation time was not different between groups (ICE group: 604.56±380.46sec vs. 585.82±373.39 sec, p=0.8). The procedure duration was slightly longer in the ICE group (82.0±20.8 vs. 72.1±19.0 min, p=0.03). Procedural success was 100% (40/40) in the ICE group and 95% (37/39) in the control group. Two control patients required crossover to ICE at a prespecified point to achieve bidirectional block. There were two femoral hematomas in the ICE group and one in the control group. The use of ICE for atrial flutter ablation is associated with less fluoroscopy time and improved ability to achieve bidirectional block compared to traditional conventional flutter ablation methods. However, it is not asoociated with reduced ablation time or overall procedure duration.

Right Ventricular Pacing for Assessment of Cavo-Tricuspid Isthmus Block.

Background: Cavo-tricuspid isthmus (CTI) dependent atrial flutter is typically treated with cardiac ablation. Standard techniques to assess CTI block after ablation can be technically challenging. Right ventricular (RV) pacing may allow for another technique to assess CTI block after ablation. Objective: The purpose of this study was to evaluate RV pacing as a method to assess CTI block after ablation of CTI dependent atrial flutter, and define endpoints of ablation using this technique. Methods: 28 patients undergoing ablation of CTI dependent atrial flutter with intact ventriculoatrial (VA) conduction were prospectively enrolled in this study and underwent the RV pacing protocol, as well as standard coronary sinus (CS) pacing techniques to assess CTI block. Results: The mean trans-isthmus conduction interval during CS pacing (TICICS) at 600 and 400ms after CTI ablation was 168 +/- 9ms and 175 +/- 18ms, respectively. The mean trans-isthmus conduction interval during RV pacing (TICIRV) at 600ms and 400ms after CTI ablation was 109 +/- 5ms and 111 +/- 5ms, respectively. A TICIRV >100ms was associated with a successful outcome after CTI ablation. Conclusions: RV pacing may add incremental value in the assessment of CTI block in patients undergoing ablation of CTI dependent atrial flutter.

Crucial role of pulmonary vein firing as an initiator of typical atrial flutter: Evidence of a close relationship between atrial fibrillation and typical atrial flutter

BackgroundSeveral studies reported that cavotricuspid isthmus-dependent atrial flutter (typical AFL) frequently coexists with atrial fibrillation (AF); however, the underlying mechanisms have not been fully investigated. This study aimed to reveal the mechanisms of the initiation of typical AFL and the association between typical AFL and AF. MethodsAmong 154 consecutive patients undergoing a first catheter ablation of AF, we investigated the appearance and mechanism of spontaneous initiation of typical AFL during catheter ablation. Then, we retrospectively investigated 67 consecutive patients without a previous AF episode who underwent typical AFL ablation. The occurrence and predictors of AF after catheter ablation were evaluated. ResultsDuring AF ablation, spontaneous initiation of typical AFL occurred during sinus rhythm in eight (5.2%) patients. The initiations of typical AFL were pulmonary vein (PV) firings except in one patient, in whom paroxysmal AF following superior vena cava firing initiated reverse typical AFL after PV isolation. After typical AFL ablation, AF occurred in 23 (34.3%) patients (mean follow up, 28.2±20.3 months). Kaplan-Meier analysis showed the occurrence of AF after typical AFL ablation to be significantly higher in the patients with a larger left atrial diameter over 40 mm (log-rank test, P=0.046). ConclusionsPV firing through AF played an important role in initiating typical AFL. The occurrence of AF after typical AFL ablation was high, and a dilated left atrium was associated with increased occurrence of AF. These findings disclosed the close relationship between typical AFL and AF, especially PV firing.

216-30: The new cavo-tricuspid isthmus dependent atrial flutter ablation dedicated 8mm gold-tip catheter performance compared to standard 8 mm platinum-iridium-tip one

Background: The “Aurum 8” study compared the clinical efficacy of standard 8 mm platinum-iridium (Pt–Ir) tip versus 8 mm gold-tip catheters in the ablation of the cavo-tricuspid isthmus dependent atrial flutter (CTI-AFL) but it did not meet the primary endpoint which was cumulative radiofrequency (RF) application duration until achieving bidirectional CTI block. The new CTI-AFL ablation dedicated 8mm gold-tip catheter is shorter compared to the standard one (95 vs 110 cm), with a double layer of stainless steel to improve stability and torqueability. It is also characterized by 270° deflection that offers anatomically optimized flexibility, smooth-move flexible mechanics, auto-lock push-pull steering, and 1:1 torsion direct motion transfer. This pilot study aimed to test whether this new CTI-AFL ablation dedicated 8mm gold-tip catheter could reduce the cumulative RF application duration until achieving bidirectional CTI block. Methods and results. This is a pilot two-centre study. We evaluated the data of 65 consecutive CTI-AFL successfully ablations (mean age 70.5 ± 10.1 years, 86.2% male) comparing 33 standard 8 mm Pt–Ir tip vs 32 new CTI-AFL ablation dedicated 8mm gold-tip catheter groups in terms of cumulative RF application duration until achieving bidirectional CTI block. The two groups did not differ for age, sex and clinical risk factors. The cumulative RF application duration until achieving bidirectional CTI block was significantly shorter in the new CTI-AFL ablation dedicated 8mm gold-tip catheter group compared with the standard 8 mm Pt–Ir tip one (276.0 ± 69.9 vs 468.3 ± 54.8 sec, p = 0.001). The new CTI-AFL ablation dedicated 8mm gold-tip catheter group had also a significantly shorter fluoroscopy time (403.8 ± 78.3 vs 592.8.5 sec, p = 0.004) and total procedure time (52.2 ± 8.6 vs 69.7 min, p < 0.001) compared to the control standard 8 mm Pt–Ir tip catheters group. Conclusions. This pilot study shows that the new CTI-AFL ablation dedicated 8mm gold-tip catheter has a significantly better performance compared to the standard 8 mm Pt–Ir tip one. This issue needs to be better addressed in specifically designed larger population and longer follow-up randomized multicenter trials.

Incidence of Atrial Fibrillation AfterAtrialFlutter Ablation.

This study was conceived to perform a comprehensive systematic review and meta-analysis of the available evidence to compute the incidence of atrial fibrillation (AF) after successful atrial flutter (AFL) catheter ablation, defined by targeting for bidirectional block, using different types of follow-up modalities and durations. Cavotricuspid-isthmus dependent AFL is usually initiated by short bursts of AF. The incidence of AF after AFL ablation is variable. We evaluated the variation in the reported incidence of AF depending on the type and duration of follow-up, and AF incidence in patients with prior AF versus no prior AF. A systematic review and meta-analysis of published studies between January 1996 and April 2015 and abstracts in the last 2 years describing patients who underwent AFL ablation and the subsequent incidence of AF was performed. Forty-eight studies were included (n = 8,257, ablation success rate: 96%, 79% male). Incidence of new-onset AF correlated with follow-up duration (29% for a weighted mean follow-up duration of 30 months). New-onset AF incidence with<2 years follow-up was 12.4% among group 1 (electrocardiogram and symptoms-driven evaluation, n=759), 19% for group 2 (outpatient Holter monitoring for 1 day to 7 days/year, n= 315), and 45% for group 3 (>7days/year Holter monitoring or by implanted cardiac devices, n= 178). Mean follow-up duration was 15.3 months, 18.5 months, and 16.3 months, respectively. In patients with and without prior AF, the incidence for AF after AFL ablation was 35.3% during mean follow-up duration of 29.7 months. In studies with<2 years follow-up duration, AF incidence was 54% in patients with prior AF versus 13.9% without prior AF (odds ratio: 7.43, 95% confidence interval: 4.96 to 11.11; p< 0.00001). In studies with >2 years follow-up duration, AF incidence was 51.3% in patients with prior AF versus 26.2% without prior AF (odds ratio: 2.93, 95% confidence interval: 2.42 to 3.56; p< 0.00001). The incidence of AF after AFL ablation is high especially in patients with prior AF when compared to those without prior AF. The detection of AF in patients without prior AF significantly increases with more frequent monitoring and/or longer follow-up duration.

The feasibility of a Box isolation strategy for non-paroxysmal atrial fibrillation in elderly patients

BackgroundCatheter ablation of non-paroxysmal atrial fibrillation (non-PAF) is a therapeutic challenge especially in elderly patients. This study describes the feasibility of a posterior left atrium isolation as a substrate modification in addition to pulmonary vein isolation, the so-called Box isolation, for elderly patients with non-PAF. MethodsTwo hundred twenty-nine consecutive patients who underwent Box isolations for drug-refractory non-PAF were divided into two groups according to their age; younger group comprising 175 patients aged <75 years and elderly group comprising 54 patients aged ≥75 years. ResultsDuring 23.7±12.0 months of follow-up, the arrhythmia-free rates after one procedure were 53.1% in younger group versus 48.1% in elderly group (p=0.50). Following the second procedure, all patients had electrical conduction recoveries along the initial Box lesion. However, a complete Box re-isolation was highly established in both age groups (87.1% vs. 92.9%, respectively; p=1.00). Recurrence of macro-reentrant atrial tachycardia was mainly associated with the gaps through the initial Box lesion in both age groups (25.8% vs. 21.4%, p=1.00), but typical cavo-tricuspid isthmus (CTI) dependent atrial flutter was significantly observed in the elderly patients’ group only (all events were observed within 6 months after the initial procedure; 3.2% vs. 28.6%, p=0.009). After two procedures, the arrhythmia-free rates increased to 73.1% in younger group versus 66.7% in elderly group (p=0.38). The occurrence rate of procedural-related complications did not differ between the two age groups, and there were no life-threatening complications even in elderly patients. ConclusionsBox isolation of non-PAF is effective and safe even in elderly patients. A prophylactic CTI ablation combined with Box isolation might be feasible to improve the long-term outcome.

Fluoroless Radiofrequency Ablation of Typical Cavotricuspid Isthmus-dependent Atrial Flutter is a Safe and Practical Procedure

Fluoroless Radiofrequency Ablation of Typical Cavotricuspid Isthmus-dependent Atrial Flutter is a Safe and Practical Procedure

Novel electrophysiological characteristics of atrioventricular nodal continuous conduction curves in atrioventricular nodal re-entrant tachycardia with concomitant cavotricuspid isthmus-dependent atrial flutter.

The detailed electrophysiological characteristics of patients with both atrioventricular nodal re-entrant tachycardia (AVNRT) and atrial flutter (AFL) have not been clarified. This study investigated the related electrophysiological differences in a large series of patients undergoing radiofrequency catheter ablation of AVNRT. A total of 1063 clinically documented AVNRT patients underwent catheter ablation were enrolled. Before the slow pathway (SP) ablation, 61 patients (5.7%) had inducible sustained cavotricuspid isthmus (CTI)-dependent AFL (Group 1), and the others (94.3%) without inducible sustained CTI-dependent AFL were defined as Group 2. The electrophysiological characteristics of these two groups and effect of the SP ablation on the inducibility of AFL were assessed. In Group 1, 36 patients (59%) had inducible/sustained AFL after the ablation of AVNRT and required a CTI ablation. The Group 1 patients had more AVNRT with continuous atrioventricular (AV) node function curves (P < 0.001, odds ratio = 7.55 [3.70-16.7], multivariate regression), and a younger age (P = 0.02, odds ratio = 1.02 [1.003-1.03], multivariate regression) than Group 2. The other characteristics were comparable between the two groups. The long-term follow-up (64.9 ± 34.9 months) revealed that the recurrence of AFL/atrial fibrillation was similar between the two groups (P > 0.05). Atrioventricular nodal re-entrant tachycardia patients with concomitant CTI-dependent AFL had more continuous AV node function curves. Forty-one per cent of these patients had non-inducible AFL after the SP ablation, indicating a slow conduction isthmus in the triangle of Koch area.

Impact of previous cardiac surgery on long-term outcome of cavotricuspid isthmus-dependent atrial flutter ablation.

The aim of this study was to determine the acute and long-term outcome of radiofrequency catheter ablation (RFCA) for cavotricuspid isthmus-dependent atrial flutter (CTI-AFL) in adults with and without previous cardiac surgery (PCS), and predictors of these outcomes. Structural alterations of the anatomical substrate of the CTI-AFL are observed in post-operative patients, and these may have an impact on the acute success of the ablation and in the long-term. Clinical records of consecutive adults undergoing RFCA of CTI-AFL were analysed. Two main groups were considered: No PCS and PCS patients, who were further subdivided into acquired heart disease (AHD: ischaemic heart disease and valvular/mixed heart disease) and congenital heart disease [CHD: ostium secundum atrial septal defect (OS-ASD) and complex CHD]. Multivariate analysis identified clinical and procedural factors that predicted acute and long-term outcomes. A total of 666 patients (73% men, age 65 ± 12 years) were included: 307 of them with PCS. Ablation was successful in 647 patients (97%), 96% in the PCS group and 98% in the No PCS group (P = 0.13). Regression analysis showed that surgically corrected complex CHD was related to failure of the procedure [odds ratio 5.6; 95% confidence interval (CI) 1.6-18, P = 0.008]. After a follow-up of 45 ± 15 months, recurrences were observed in 90 patients (14%), more frequently in the PCS group: absolute risk of recurrence 18 vs. 10.5%, relative risk 1.71, 95% CI: 1.2-2.5, P = 0.006. Multivariate analysis indicated that the types of PCS [OS-ASD vs. No PCS: hazard ratio (HR) 2.57; 95% CI: 1.1-6.2, P = 0.03 and complex CHD vs. No PCS: HR 2.75; 95% CI: 1.41-5.48, P = 0.004], female gender (HR 1.55; 95% CI: 1.04-2.4, P = 0.048), and severe LV dysfunction (HR 1.36; 95% CI: 1.06-1.67, P = 0.04) were independent predictors of long-term recurrence. Radiofrequency catheter ablation of CTI-AFL after surgical correction of AHD and CHD is associated with high acute success rates. The severity of the structural alterations of the underlying heart disease and consequently the type of surgical correction correlates with higher risk for recurrence.

Long-Term Outcome After Ablation of Right Atrial Tachyarrhythmias After the Surgical Repair of Congenital and Acquired Heart Disease

Atrial myopathy, atriotomies, and fibrotic scars are the pathophysiological substrate of lines of conduction block, promoting atrial macroreentry. The aim of this study was to determine the acute and long-term outcome of radiofrequency catheter ablation (RFCA) for right atrial tachyarrhythmia (AT) in adults after cardiac surgery for congenital heart disease (CHD) and acquired heart disease (AHD) and predictors of these outcomes. Clinical records of adults after surgery for heart disease undergoing RFCA of right-sided AT were analyzed retrospectively. Multivariate analyses identified clinical and procedural factors predicting acute and long-term outcomes. A total of 372 patients (69% men; age 61 ± 15years) after surgical repair of CHD (n= 111) or AHD (n= 261) were studied. Cavotricuspid isthmus-dependent atrial flutter (CTI-AFL) was observed in 300 patients and non-CTI-AFL in 72 patients. Ablation was successful in 349 cases (94%). During a mean follow-up of 51 ± 30months, recurrences were observed in 24.5% of patients. Multivariate analysis showed that non-CTI-AFL (hazard ratio [HR] 1.78, 95% confidence interval [CI] 1.1 to 2.9) and CHD (HR 1.75, 95% CI 1.07 to 2.9) were independent predictors of long-term recurrences. Multivariate analysis showed that female gender (HR 2.29, 95% CI 1.6 to 3.3), surgery for AHD (HR 95% 2.31, 95% CI 1.5 to 3.7), and left atrial dilatation (HR 2.1, 95% CI 1.3 to 3.2) were independent predictors of long-term atrial fibrillation. In conclusion, RFCA of right-sided AT after cardiac surgery is associated with high acute success rates and significant long-term recurrences. Non-CTI-dependent AFL and surgery for CHD are at higher risk of recurrence. Atrial fibrillation is common during follow-up, particularly in patients with AHD and enlarged left atrium.

Impact of Impaired Renal Function on the Incidence of Atrial Fibrillation following Radiofrequency Ablation of Cavotricuspid Isthmus-Dependent Atrial Flutter.

Background and ObjectivesAtrial fibrillation (AF) occurs frequently after successful radiofrequency ablation (RFA) of cavotricuspid isthmus-dependent atrial flutter (CTI-AFL). Renal impairment has been implicated in the development of AF. The purpose of this study is to clarify the impact of impaired renal function on the incidence of AF after RFA of CTI-AFL.Subjects and MethodsBetween January 2001 and December 2013, 240 non-dialysis patients with no prior history of AF {mean age 55.9±15.2 years old; male, 192 (80.0%)} who had undergone successful CTI-AFL ablation were included in the present study. The baseline estimated glomerular filtration rate was calculated, and patients were divided into those with impaired renal function (<60 mL/min/1.73 m2) and those with preserved renal function (≥ 60 mL/min/1.73 m2). The incidence of AF was retrospectively analyzed.Results69 (28.8%) patients experienced new onset AF during a median follow-up duration of 26 months (inter-quartile, 7-53). The incidence of AF was significantly higher in patients with impaired renal function than in those with preserved renal function {13/25 (52.0%) versus 56/215 (26.0%), log rank p=0.019}. Age, CHADS2 score, impaired renal function, and left atrial diameter were significantly associated with the incidence of AF in univariate Cox regression analysis. Multivariate analysis showed that age was the only significant predictor of AF incidence (hazard ratio, 1.024; 95% confidence interval, 1.004-1.044, p=0.020).ConclusionPatients with impaired renal function may require careful attention for the incidence of new onset AF following successful RFA of CTI-AFL.

Catheter Ablation of Sinus Node Reentrant Tachycardia with a Non-Contact Mapping System

We describe a case of 47-year-old man who suffered a sinus node reentrant tachycardia and a typical counterclockwise cavotricuspid isthmus dependent atrial flutter. The dynamic isopotential mapping with non-contact mapping system showed that source and propagation sequence of the sinus node reentrant tachycardia almost identical to that of sinus rhythm, only the foremost was slightly different. The ablation on the source point terminated the tachycardia. The characteristics of the target electrogram in tachycardia were fractional and before onset of surface ECG P wave.

Atypical Electrocardiographic Features of Cavotricuspid Isthmus-Dependent Atrial Flutter Occurring During Left Atrial Ablation for Atrial Fibrillation

Atypical Electrocardiographic Features of Cavotricuspid Isthmus-Dependent Atrial Flutter Occurring During Left Atrial Ablation for Atrial Fibrillation

Atrial tachycardias occurring late after open heart surgery.

Atrial tachycardias are common after open heart surgery. Most commonly these are macro-reentrant including cavotricuspid isthmus dependent atrial flutter, incisional right atrial flutter and left atrial flutter. Focal atrial tachycardias occur less frequently. The specific type of atrial tachycardia highly depends on the type of surgical incision. Catheter ablation can be very effective, however requires a thorough understanding of anatomy and surgical technique.

GW25-e4293 Evaluation of the efficacy of different ablation strategies on cavotricuspid isthmus-dependent atrial flutter

GW25-e4293 Evaluation of the efficacy of different ablation strategies on cavotricuspid isthmus-dependent atrial flutter

Successful ablation of cavo-tricuspid isthmus dependent atrial flutter in a patient with Senning operation

Successful ablation of cavo-tricuspid isthmus dependent atrial flutter in a patient with Senning operation

Clinical characteristics and long-term follow-up after ablation of right atrial macro-reentrant tachyarrhythmias following surgical repair of congenital and acquired heart disease

Introduction: The surgical repair of congenital (CHD) and acquired (AHD) heart disease (both ischemic and valvular heart disease) involves the creation of lines of block that generate a complex pathophysiological substrate, promoting atrial reentry. Radiofrequency catheter ablation (ABL) can treat these atrial tachyarrhythmias. The aim of our study was to describe the long-term follow-up of patients with previous cardiac surgery undergoing right atrial macro-reentrant tachyarrhythmia ablation. Methods: Multicenter study. Clinical characteristics, long-term follow-up and predictors of atrial fibrillation (AFib) development were analyzed. Results: A total of 372 patients were included (69% men), 111 of them had undergone surgical repair of CHD (42% ostium secundum atrial septal defect), while 261 were postoperative of AHD (isolated CABG in 38%, isolated valve disease in 51% and mixed procedures in 11%). Mean age was 61 years (IQ range 52-73y). Cavo-tricuspid isthmus-dependent atrial flutter (CTI-AFL) was observed in 300 patients: 239 (92%) patients with AHD and 61 (55%) patients with CHD; and intra-atrial re-entrant tachycardia (IART) in 72 patients. Ablation was successful in 349 cases (94%) (96% of CTI-AFL and 88% of IART). After a median follow-up of 47 months (IQ 18-73), 119 (32%) patients developed AFib. AFib rates were higher in AHD than CHD patients (35% vs 24%, p=0.04). Hospital admission for heart failure was required in 68 (18%) patients. A total of 55 (15%) patients required pacemaker implantation. At the end of follow-up, 255 (69%) patients were in sinus rhythm and 81 (22%) in AFib. Overall mortality was 15%. Multivariate analysis showed that female gender (HR 2.33, 95% IC 1.59-3.34), surgery for AHD (HR 95% 2.44, 95% IC 1.54-3.87) and left atrial dilation (HR 2.1, 95% IC 1.3-3.2) were independent predictors of long term AFib presentation. Conclusion: Radiofrequency ablation of right atrial macro-reentrant tachyarrhythmias after surgical correction of acquired and congenital heart disease is associated with high rates of acute efficacy. Atrial fibrillation and heart failure were common events during follow-up, especially in patients operated for acquired heart disease and with dilated atrial chambers.

Long‐Term Outcome Following Ablation of Atrial Tachycardias Occurring after Mitral Valve Replacement in Patients with Rheumatic Heart Disease

Atrial tachycardia (AT) is a frequent late sequel of surgical valve replacement procedures in patients with rheumatic heart disease (RHD). The aim of this study was to evaluate the acute and long-term outcome of catheter ablation in such patients. A total of 21 consecutive RHD patients with AT after a valve replacement were enrolled in this study. The mean interval between the occurrence of symptomatic AT and the surgical intervention was 38.2 ± 48.7 months. The initial procedure was performed 8.4 ± 8.9 months after first onset of AT. During the first procedure, an electroanatomic mapping was completed for 25 ATs, 18 of which were cavotricuspid isthmus-dependent atrial flutter, five that were right atrial free wall AT, and two that were left AT. Acute success was obtained in 95% (20/21) patients. Nine patients with recurrent AT had repeat radiofrequency catheter ablation, and newly developed left AT was identified in five patients after the first right AT ablation. After a mean follow-up of 42.7 ± 17.3 months, only 33% of the patients remained free of ATs, while 14% and 53% of the patients had AT recurrence and the development of atrial fibrillation (AF), respectively. Right but not left macroreentry is the most common AT postmitral valve replacement in patients with RHD. The incidence of AF is very high after AT ablation in such patients during the long-term follow-up.

Catheter Ablation of Atrial Arrhythmias After Cardiac Transplantation: Findings at EP Study Utility of 3‐D Mapping and Outcomes

Management of atrial arrhythmias (AA) in orthotopic heart transplant (OHT) patients is challenging. The purpose of this study was to define the mechanisms of these arrhythmias and to evaluate the role of ablation. Patients with OHT referred for ablation of AA from 1999 to 2011 were included (n = 15). Entrainment and anatomic 3-D mapping were utilized to identify AA mechanism and guide ablation. The median time from OHT to ablation was 8 years (range: 1 month-16 years). AA types included 1 (7%) AVNRT, 5 (33%) cavotricuspid isthmus (CTI) dependent donor atrial flutter (AFl), 3 (20%) non-CTI-dependent donor AFL (n = 3), focal atrial tachycardia (AT) (n = 2) and in 4 (27%) recipient to donor atria conduction (RDC) that involved the right atrial anastomosis in 3 and left atrial anastamosis in 1 patient. In RDC tachycardia, ablation was performed at the site of earliest donor atrial activation on the suture line. AA in the recipient atria were not targeted. This resulted in acute success in all cases. In most patients 12/15 (80%) only right atrial ablation was necessary. Regardless of surgical technique (bicaval vs biatrial) right-sided AA was most common. Acute success occurred in 14/15 (93%) patients and 3/15 (20%) required repeat Abl for recurrence. There were no major complications. AA after OHT are most commonly due to atrial macroreentry, but focal arrhythmias and RDC atrial conduction also occur. Ablation of organized AA is usually successful with low risk, warranting early consideration in preference to medical treatment.