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Prashanthan Sanders

Publications and source records attributed to Prashanthan Sanders.

At least 37 records · Page 2Linked to original sources
PubMed2006

Fibrillating areas isolated within the left atrium after radiofrequency linear catheter ablation.

INTRODUCTION: Nonpulmonary vein sources have been implicated as potential drivers of atrial fibrillation (AF). This observational study describes regions of fibrillating atrial tissue isolated inadvertently from the left atrium (LA) following linear catheter ablation for AF. METHODS AND RESULTS: We report four patients with persistent/permanent AF who underwent pulmonary vein isolation with additional linear lesions and who presented with recurrent AF (mean AF cycle length [AFCL] 175-270 ms). Further catheter ablation resulted in the inadvertent electrical isolation of significant areas of the LA in which AF persisted at the same AFCL as was measured prior to disconnection, despite the restoration of sinus rhythm (SR) in all other left and right atrial areas, strongly suggesting that these islands were driving the remaining atria into fibrillation. The disconnected areas were located in the lateral LA, including the left atrial appendage (LAA) in three patients (limited to the LAA in one) and in the posterior LA in one patient. These isolated fibrillating regions represented 15-24% of the global LA surface, as estimated by electroanatomic mapping. CONCLUSION: Fibrillation can be maintained within electrically isolated regions of the LA following catheter ablation of AF, demonstrating the importance of atrial drivers in the maintenance of AF. Further mapping of these drivers is needed to characterize their mechanism and thereby allow for a more specific ablation strategy.

Aged↗
PubMed2006

Frequency mapping of the pulmonary veins in paroxysmal versus permanent atrial fibrillation.

INTRODUCTION: The pulmonary veins (PVs) are a dominant source of triggers initiating atrial fibrillation (AF). While recent evidence implicates these structures in the maintenance of paroxysmal AF, their role in permanent AF is not known. The current study aims to compare the contribution of PV activity to the maintenance of paroxysmal and permanent AF. METHODS AND RESULTS: Thirty-four patients with paroxysmal AF (n = 20) or permanent AF (n = 14) undergoing ablation were studied. Prior to ablation, 32 seconds of electrograms were acquired from each PV and the coronary sinus (CS). The frequency of activity of each PV and CS was defined as the highest amplitude frequency on spectral analysis. The effects of ablation on the AF cycle length (AFCL) and frequency and on AF termination were determined. Significant differences were observed between paroxysmal and permanent AF. Paroxysmal AF demonstrates higher frequency PV activity (11.0 +/- 3.1 vs 8.8 +/- 3.0 Hz; P = 0.0003) but lower CS frequency (5.8 +/- 1.2 vs 6.9 +/- 1.4 Hz; P = 0.01) and longer AFCL (182 +/- 17 vs 158 +/- 21 msec; P = 0.002), resulting in greater PV to atrial frequency gradient (7.2 +/- 2.2 vs 4.2 +/- 2.9 Hz; P = 0.006). PV isolation in paroxysmal AF resulted in a greater decrease in atrial frequency (1.0 +/- 0.7 vs -0.05 +/- 0.4 Hz; P < 0.0001), greater prolongation of the AFCL (49 +/- 35 vs 5 +/- 6 msec; P < 0.0001), and more frequent AF termination (11/20 vs 0/14; P = 0.0007) compared to permanent AF. CONCLUSION: Paroxysmal AF is associated with higher frequency PV activity and lesser CS frequency compared to permanent AF. Isolation of the PVs had a greater impact on the fibrillatory process in paroxysmal AF compared to permanent AF, suggesting that while the PVs have a role in maintaining paroxysmal AF, these structures independently contribute less to the maintenance of permanent AF.

Adult↗
PubMed2005

Techniques, evaluation, and consequences of linear block at the left atrial roof in paroxysmal atrial fibrillation: a prospective randomized study.

BACKGROUND: There are no reports describing the technique, electrophysiological evaluation, and clinical consequences of complete linear block at roofline joining the superior pulmonary veins (PVs) in patients with paroxysmal atrial fibrillation (AF). METHODS AND RESULTS: Ninety patients with drug-refractory paroxysmal AF undergoing radiofrequency ablation were prospectively randomized into 2 ablation strategies: (1) PV isolation (n=45) or (2) PV isolation in combination with linear ablation joining the 2 superior PVs (roofline; n=45). In both groups, the cavotricuspid isthmus, fragmented peri-PV-ostial electrograms, and spontaneous non-PV foci were ablated. Roofline ablation was performed at the most cranial part of the left atrium (LA) with complete conduction block demonstrated during LA appendage pacing by the online mapping of continuous double potential and an activation detour propagating around the PVs to activate caudocranially the posterior wall of the LA. The effect of ablation at the LA roof was evaluated by the change in fibrillatory cycle length, termination and noninducibility of AF, and clinical outcome. PV isolation was achieved in all patients with no significant differences in the radiofrequency duration, fluoroscopy, or procedural time between the groups. Roofline ablation required 12+/-6 (median 11, range 3 to 25) minutes of radiofrequency energy delivery with a fluoroscopic duration of 7+/-2 minutes and was performed in 19+/-7 minutes. Complete block was confirmed in 43 patients (96%) and resulted in an activation delay that was shorter circumventing the left than the right PVs during LA appendage pacing (138+/-15 versus 146+/-25 ms, respectively; P=0.01). Roofline ablation resulted in a significant increase in the fibrillatory cycle length (198+/-38 to 217+/-44 ms; P=0.0005), termination of arrhythmia in 47% (8/17), and subsequent noninducibility of AF in 59% (10/17) of the patients inducible after PV isolation. However, LA flutter, predominantly perimitral, could be induced in 10 patients (22%) after roofline ablation. At 15+/-4 months, 87% of the roofline group and 69% with PV isolation alone are arrhythmia free without antiarrhythmics (P=0.04). CONCLUSIONS: This prospective randomized study demonstrates the feasibility of achieving complete linear block at the LA roof. Such ablation resulted in the prolongation of the fibrillatory cycle, termination of AF, and subsequent noninducibility and is associated with an improved clinical outcome compared with PV isolation alone.

Adult↗
PubMed2005

Characterization of focal atrial tachycardia using high-density mapping.

OBJECTIVES: The goal of this study was to characterize the origin of focal atrial tachycardias (AT). BACKGROUND: Focal ATs originate from a small area and spread centrifugally; however, activation at the AT origin has not been characterized. METHODS: Twenty patients with AT having failed prior ablation or occurring after atrial fibrillation ablation were studied. After excluding macro-re-entry, AT was mapped using a 20-pole catheter (five radiating spines; diameter 3.5 cm), performing vector mapping to identify the earliest activity followed by high-density mapping at the AT origin. Localized re-entry was considered if >85% of the tachycardia cycle length (CL) was observed within the mapping field and was confirmed by entrainment. RESULTS: A total of 27 ATs were mapped to the pulmonary vein ostia (n = 5), and left (n = 16) and right atria (n = 6). A localized focus was evidenced at the site of origin in 19 ATs (70%), whereas in 8 (30%), localized re-entry was evidenced by 95.2 +/- 4.5% of the tachycardia CL recorded within the mapping field and entrainment showed a post-pacing interval <20 ms longer than tachycardia CL (6 of 6 tested). Localized re-entry had a shorter CL (p = 0.009), slowed conduction at its origin (fractionated potential 115 +/- 19 ms vs. 64 +/- 22 ms, representing 49 +/- 10% and 20 +/- 10% of tachycardia CL, respectively; p < 0.0001), and were more often contiguous with regions of electrical silence or conduction abnormalities (88% vs. 32%; p = 0.01). In addition, mapping documented varying degrees of intra-atrial conduction block, preferential conduction (n = 5), and rapid bursts of myocardial activity (n = 1). At 11 +/- 7 months, none have had recurrence of AT. CONCLUSIONS: High-density multielectrode mapping can be used to perform vector mapping to localize complex AT. It provides novel insight into the mechanisms of focal AT, distinguishing focal AT from localized re-entry.

Adult↗
PubMed2005

Spectral analysis identifies sites of high-frequency activity maintaining atrial fibrillation in humans.

BACKGROUND: The identification of sites of dominant activation frequency during atrial fibrillation (AF) in humans and the effect of ablation at these sites have not been reported. METHODS AND RESULTS: Thirty-two patients undergoing AF ablation (19 paroxysmal, 13 permanent) during ongoing arrhythmia were studied. Electroanatomic mapping was performed, acquiring 126+/-13 points per patient throughout both atria and coronary sinus. At each point, 5-second electrograms were obtained to determine the highest-amplitude frequency on spectral analysis and to construct 3D dominant frequency (DF) maps. The temporal stability of the recording interval was confirmed in a subset. Ablation was performed with the operator blinded to the DF maps. The effect of ablation at sites with or without high-frequency DF sites (maximal frequencies surrounded by a decreasing frequency gradient > or =20%) was evaluated by determining the change in AF cycle length (AFCL) and the termination and inducibility of AF. The spatial distribution of the DF sites was different in patients with paroxysmal and permanent AF; paroxysmal AF patients were more likely to harbor the DF site within the pulmonary vein, whereas in permanent AF, atrial DF sites were more prevalent. Ablation at a DF site resulted in significant prolongation of the AFCL (180+/-30 to 198+/-40 ms; P<0.0001; kappa=0.77), whereas in the absence of a DF site, there was no change in AFCL (169+/-22 to 170+/-22 ms; P=0.4). AF terminated during ablation in 17 of 19 patients with paroxysmal and 0 of 13 with permanent AF (P<0.0001). When 2 patients with nonsustained AF during mapping were excluded, 13 of 15 (87%) had AF termination at DF sites (54% at the initially ablated DF site): 11 pulmonary veins and 2 atrial. In addition, AF could no longer be induced in 69% with termination of AF at a DF site. There were no significant differences in the number or percentage of DF sites detected (5.4+/-1.6 versus 4.9+/-2.1; P=0.3) and ablated (1.9+/-1.0 versus 2.4+/-1.0; P=0.3) in those with and without AF termination. The duration of radiofrequency ablation to achieve termination was significantly shorter than that delivered in those with persisting AF (34.8+/-24.0 versus 73.5+/-22.9 minutes; P=0.0002). All patients with persisting AF had additional DF sites outside the ablated zones. CONCLUSIONS: Spectral analysis and frequency mapping identify localized sites of high-frequency activity during AF in humans with different distributions in paroxysmal and permanent AF. Ablation at these sites results in prolongation of the AFCL and termination of paroxysmal AF, indicating their role in the maintenance of AF.

Amiodarone↗
PubMed2005

Reduction of fluoroscopy exposure and procedure duration during ablation of atrial fibrillation using a novel anatomical navigation system.

AIMS: Catheter ablation of atrial fibrillation (AF) is centred on pulmonary vein (PV) ablation with or without additional atrial substrate modification. These procedures may be prolonged with significant fluoroscopy exposure. This study evaluates a new non-fluoroscopic navigation system during ablation of AF. METHODS AND RESULTS: Seventy-two patients undergoing catheter ablation of symptomatic drug refractory AF were prospectively randomized to ablation with (n=35; study group) or without (n=37; control group) non-fluoroscopic navigation. PV isolation was performed in all patients. In patients with persistent or inducible sustained AF after PV isolation linear ablation was performed by joining the superior PVs. PV isolation was achieved in all patients; fluoroscopy (15.4+/-3.4 vs. 21.3+/-6.4 min; P<0.001) and procedural (52+/-12 vs. 61+/-17 min; P=0.02) durations were significantly reduced in the study group. Linear block was achieved in 37 of the 39 patients; with a significant reduction in fluoroscopy (5.6+/-2.2 vs. 9.9+/-4.8 min; P=0.003) and procedural (14.7+/-5.5 vs. 26.6+/-16.9 min; P=0.007) durations in the study group. After a follow-up of 6.9+/-2.9 months (range 3-10), 26 (74%) patients in the non-fluoroscopic navigation group and 29 (78%) patients in the control group were arrhythmia-free after the first procedure. CONCLUSION: This prospectively randomized study demonstrates significant reduction of fluoroscopy exposure and procedural duration using supplementary non-fluoroscopic imaging system for AF ablation.

Adult↗
PubMed2005

Prevalence of pulmonary vein disconnection after anatomical ablation for atrial fibrillation: consequences of wide atrial encircling of the pulmonary veins.

AIMS: Anatomical and wide atrial encircling of the pulmonary veins (PVs) has been proposed as a cure of atrial fibrillation (AF). We evaluated the acute achievement of electrical PV isolation using this approach. In addition, the consequences of wide encircling of the PVs with isolation were assessed. METHODS AND RESULTS: Twenty patients with paroxysmal AF were studied. Anatomically guided ablation was performed utilizing the CARTO system to deliver coalescent lesions circumferentially around each PV to produce a voltage reduction to <0.1 mV, with the operator blinded to recordings of circumferential PV mapping. After achieving the anatomical endpoint, the incidence of residual conduction and the amplitude and conduction delay of residual PV potentials were determined. Electrical isolation of the PV was then performed and the residual far-field potentials evaluated. Individual PV ablation was performed in all PVs. Anatomically guided PV ablation was performed for 47.3+/-11 min, after which 44 (55%) PVs were electrically isolated. In the remaining 45%, despite abolition of the local potential at the ablation site, PV potentials [amplitude 0.2 mV (range 0.09-0.75) and delay of 50.3+/-12.6 ms] were identified by circumferential mapping. After electrical isolation (12.2+/-11.7 min ablation), 55 (69%) PVs demonstrated far-field potentials; with a greater incidence (P=0.015) and amplitude (P=0.021) on the left compared with the right PVs. At 13.2+/-8.3 months follow-up, 13 patients (65%) remained arrhythmia-free without anti-arrhythmics. In four patients (20%), spontaneous sustained left atrial macrore-entry required re-mapping and ablation. Macrore-entry was observed to utilize regions around or bordering the previous ablation as its substrate. CONCLUSION: Anatomically guided circumferential PV ablation results in apparently coalescent but electrically incomplete lesions with residual conduction in 45% of PVs. Wide encircling of the PVs was associated with left atrial macrore-entry in 20% of patients.

Atrial Fibrillation↗
PubMed2005

Correlation of atrial electrocardiographic amplitude with radiofrequency energy required to ablate cavotricuspid isthmus-dependent atrial flutter.

OBJECTIVES: The purpose of this study was to evaluate a possible correlation between atrial ECG amplitude in common atrial flutter (AFL) and radiofrequency (RF) energy required to achieve cavotricuspid isthmus block. BACKGROUND: The amount of RF delivery required for ablation of typical AFL is variable. This variation has been attributed to the cavotricuspid isthmus anatomy. Atrial ECG amplitude can be a marker of atrial anatomic variations and therefore may correlate with RF duration required to achieve cavotricuspid isthmus block. METHODS: Seventy consecutive patients were prospectively studied. Ablation of the cavotricuspid isthmus was performed by creating a line of block between the inferior tricuspid annulus and the inferior caval vein using 8-mm-tip electrode catheters. If more than 20 minutes of RF time was required to achieve conduction block, the catheter was changed to an irrigated-tip catheter. Atrial ECG amplitude was assessed in leads II, III, aVF, and aVL. RESULTS: A total of 14 +/- 11 minutes of RF energy was delivered to achieve block in all patients; 12 patients (8%) required more than 20 minutes. Atrial ECG amplitude showed highly significant correlations with cumulative RF energy (F and P waves in lead II: r = 0.703 and r = 0.737, P < .001). P-wave amplitude <0.2 mV and/or flutter wave amplitude <0.35 mV in lead II have a high negative predictive value to predict <20 min RF delivery (96% and 89% respectively). CONCLUSIONS: A significant correlation exists between atrial ECG amplitude and amount of RF required to ablate typical AFL. Atrial ECG amplitude may be a surrogate marker of characteristics of isthmus anatomy. These findings may influence the choice of catheter used for cavotricuspid isthmus ablation.

Aged↗
PubMed2005

Left atrial linear ablation to modify the substrate of atrial fibrillation using a new nonfluoroscopic imaging system.

Linear left atrial ablation is performed in combination with pulmonary vein (PV) isolation to improve the clinical results of atrial fibrillation (AF) ablation. These procedures require long procedures and fluoroscopic exposure. The aim of the present study was to evaluate the performance of a new, nonfluoroscopic, real-time, three-dimensional navigation system for linear ablation at the left atrial roof and mitral isthmus. The study included 44 patients (54 +/- 10 years of age, 5 women) with drug-refractory AF, who underwent roof line or mitral isthmus linear ablation after 4-PV isolation. In 22 patients, ablation was performed with the navigation system (test group), and in the remainders linear ablation was performed with fluoroscopic guidance alone (control group). Conduction block was achieved in 20 patients (91%) in test group, and 21 patients (95%) in the control group (ns). Use of the navigation system was associated with a shorter fluoroscopic exposure for roof line (5.6 +/- 3.0 minutes vs 8.7 +/- 5.0 minutes, P < 0.05), and a trend for mitral isthmus ablation (7.8 +/- 7.8 minutes vs 12.1 +/- 5.9 minutes). It was also associated with a trend toward shorter procedure times for roof line (15.3 +/- 8.6 minutes vs 22.9 +/- 16.8 minutes) and mitral isthmus line (20.2 +/- 15.8 minutes vs 32.0 +/- 7.6 minutes) but no difference in duration of radiofrequency delivery. There was no procedural complication. The use of this new nonfluoroscopic imaging system was associated with a shorter fluoroscopic exposure as well as a trend toward shorter duration of linear ablation procedures for AF.

Atrial Fibrillation↗
PubMed2005

High-density circumferential pulmonary vein mapping with a 20-pole expandable circular mapping catheter.

The differentiation of pulmonary vein (PV) electrograms from atrial far-field signals during PV isolation (PVI) for atrial fibrillation (AF) may be difficult. In addition, owing to highly variable PV ostial sizes, current fixed-diameter circular PV mapping catheters may not yield optimal electrograms. We evaluated an expandable, circular 15-25 mm diameter, 20-pole mapping catheter for PV mapping during sustained AF in 25 patients. After selective PV angiography to define the ostial position and size, the catheter was introduced into each PV and withdrawn to the most stable proximal position, with optimal wall contact ensured by progressive loop expansion. At each PV ostium, electrograms recorded at high resolution (HR) were compared with those recorded at a resolution similar to that of a standard 10-pole Lasso catheter. After PVI performed during ongoing AF, the presence of residual far-field potentials (FFP) under both set-ups was compared. We mapped 97 PV, including 4 pairs with common ostia. In the HR recordings, the PV potentials had greater amplitude (0.5 +/- 0.1 vs 0.3 +/- 0.1 mV, P = 0.001) and fragmentation, whereas left atrial FFP were minimized. After successful isolation of all PV, FFP were observed in 33% of left superior and 28% of left inferior PV on the HR recordings, compared to 66% and 61%, respectively under normal resolution. Catheter stability and optimal wall contact, in combination with HR electrograms can optimize circumferential PV mapping during AF and improve the discrimination of FFP postablation.

Atrial Fibrillation↗
PubMed2005

Incidence and prevention of cardiac tamponade complicating ablation for atrial fibrillation.

Cardiac tamponade complicating catheter ablation of atrial fibrillation (AF) occurs in approximately 1% of pulmonary vein isolation (PVI), and up to 6% of linear ablation procedures. We reviewed 348 consecutive AF ablation (including repeat) procedures over 1 year, which all included PVI, with additional linear lesions at the mitral isthmus in 73%, and cavotricuspid isthmus (CTI) in 76%. An irrigated-tip ablation catheter was used, with power limited to 25-35 W for PVI and 45-60 W for linear lesions. Tamponade occurred in seven men and three women (2.9% of the population) during the creation of linear ablation lesions. Mechanical perforations occurred in two patients, and "popping" during radiofrequency (RF) energy delivery at the mitral isthmus in six, and at the CTI in two patients. Peak RF power was significantly higher in patients with than without tamponade (53 +/- 4 W vs 48 +/- 7 W; P = 0.02), and was greater than 48 W in all cases of "popping." In the following year, RF power for linear ablation was limited to </=42 W. Among 398 procedures, tamponade occurred in four patients (1.0%; P = 0.047 vs first year), three from "popping" and one from mechanical trauma. Procedural success rate remained the same despite reduction of power. Risk of tamponade was highest during linear ablation, mainly associated with high energy delivery and "popping." Reducing the energy limited, though did not eliminate this complication.

Aged↗
PubMed2005

Clinical predictors of noninducibility of sustained atrial fibrillation after pulmonary vein isolation.

BACKGROUND: Noninducibility of sustained atrial fibrillation (AF) after pulmonary vein isolation (PVI) has been shown to be associated with a better clinical outcome. We evaluated the role of clinical variables that could predict noninducibility of sustained AF after PVI. METHODS AND RESULTS: Data were collected prospectively from 181 patients (153 male; age 54 +/- 9 years) referred for ablation of drug-refractory symptomatic paroxysmal AF (duration < or =7 days). Clinical variables were evaluated with regard to their ability of predicting noninducibility of sustained AF (< or =10 minutes) after PVI. Univariate analysis was performed on all collected variables followed by multivariate analysis for variables showing a P value <0.1. After PVI, sustained AF was noninducible in 97 (54%) patients. The following clinical variables showed a significant difference between the groups: body weight, longest AF episode, duration of AF history, presence or absence of structural heart disease, left ventricular (LV) hypertrophy, prior cardioversion, left atrial (LA) parasternal, and longitudinal diameters and LV diameters. On multivariate analysis, three independent predictors of noninducibility were identified: a shorter duration of AF episodes (AF <12 hours: RR 0.01 (0.002-0.06), P < 0.001; AF 12-48 hours: RR 0.07 (0.01-0.37), P = 0.001); LA longitudinal diameter <57 mm (RR 0.33 (0.13-0.82), P = 0.016); and absence of LV hypertrophy (RR 0.15 (0.04-0.63), P = 0.01). CONCLUSIONS: Shorter AF episodes, smaller LA longitudinal diameter, and absence of LV hypertrophy are independent predictors of noninducibility of sustained AF after PVI.

Adult↗
PubMed2005

Catheter ablation of long-lasting persistent atrial fibrillation: critical structures for termination.

BACKGROUND: The relative contributions of different atrial regions to the maintenance of persistent atrial fibrillation (AF) are not known. METHODS: Sixty patients (53 +/- 9 years) undergoing catheter ablation of persistent AF (17 +/- 27 months) were studied. Ablation was performed in a randomized sequence at different left atrial (LA) regions and comprised isolation of the pulmonary veins (PV), isolation of other thoracic veins, and atrial tissue ablation targeting all regions with rapid or heterogeneous activation or guided by activation mapping. Finally, linear ablation at the roof and mitral isthmus was performed if sinus rhythm was not restored after addressing the above-mentioned areas. The impact of ablation was evaluated by the effect on the fibrillatory cycle length in the coronary sinus and appendages at each step. Activation mapping and entrainment maneuvers were used to define the mechanisms and locations of intermediate focal or macroreentrant atrial tachycardias. RESULTS: AF terminated in 52 patients (87%), directly to sinus rhythm in 7 or via the ablation of 1-6 intermediate atrial tachycardias (total 87) in 45 patients. This conversion was preceded by prolongation of fibrillatory cycle length by 39 +/- 9 msec, with the greatest magnitude occurring during ablation at the anterior LA, coronary sinus and PV-LA junction. Thirty-eight atrial tachycardias were focal (originating dominantly from these same sites), while 49 were macroreentrant (involving the mitral or cavotricuspid isthmus or LA roof). Patients without AF termination displayed shorter fibrillatory cycles at baseline: 130 +/- 14 vs 156 +/- 23 msec; P = 0.002. CONCLUSION: Termination of persistent AF can be achieved in 87% of patients by catheter ablation. Ablation of the structures annexed to the left atrium-the left atrial appendage, coronary sinus, and PVs-have the greatest impact on the prolongation of AF cycle length, the conversion of AF to atrial tachycardia, and the termination of focal atrial tachycardias.

Atrial Fibrillation↗
PubMed2005

Catheter ablation of long-lasting persistent atrial fibrillation: clinical outcome and mechanisms of subsequent arrhythmias.

BACKGROUND: Catheter ablation of atrial fibrillation (AF) is challenging in patients with long-standing persistent AF. The clinical outcome and subsequent arrhythmia recurrence after using an ablation method targeting multiple left atrial sites with the aim of achieving acute AF termination has not been characterized. METHODS: Sixty patients (mean age: 53 +/- 9 years) with persistent AF (mean duration: 17 +/- 27 months) were prospectively followed after catheter ablation. Catheter ablation targeting the following sites was performed in a random sequence: (i) electrical isolation of all pulmonary veins (PV); (ii) disconnection of other thoracic veins; (iii) atrial ablation at sites possessing complex electrical activity, activation gradients, or short cycle lengths. Finally, linear ablation of the LA roof and mitral isthmus was performed if sinus rhythm was not restored following energy delivery to the above sites. At 1, 3, 6, and 12 months after ablation, patients underwent clinical review and 24-hour ambulatory ECG monitoring to identify asymptomatic arrhythmia. Repeat mapping and catheter ablation was performed in any patient experiencing recurrent atrial tachycardia (AT). Clinical success was defined as the absence of any sustained atrial arrhythmia. RESULTS: AF terminated during ablation in 52 patients (87%). The fluoroscopy and procedural durations were 84 +/- 30 minutes and 264 +/- 77 minutes, respectively. Three months after ablation, sustained ATs were documented in 24 patients (associated with AF in 2). Mapping in 23 patients showed a single AT in 7 while multiple ATs were observed in 16. Macroreentry was confirmed to be due to gaps in the ablation lines, while focal ATs originated from discrete sites or isthmuses near the left atrial appendage, coronary sinus, pulmonary veins, or fossa ovalis; these sites were similar to those at which the greatest impact was observed on the fibrillatory process during the initial ablation procedure. After repeat ablation, at 11 +/- 6 months of follow-up, 57 patients (95%) were in sinus rhythm and 3 developed recurrent AF or AT. All patients in sinus rhythm demonstrated improved exercise capacity and all but 2 had evidence of atrial transport as assessed by Doppler echocardiography (mitral A wave velocity 34 +/- 17 cm/sec) by 6 months. CONCLUSION: Catheter ablation of long-lasting persistent AF associated with acute AF termination achieves medium to long-term restoration and maintenance of sinus rhythm in 95% of patients. Arrhythmia recurrence in the majority of patients is AT.

Adult↗