Temporal distribution of arrhythmic events in chronic kidney disease: Highest incidence in the long interdialytic period.

BACKGROUND: Chronic kidney disease (CKD) patients undergoing hemodialysis (HD) have a high risk of sudden cardiac death (SCD). A unique risk factor may be a longer interval between HD sessions (interdialytic period). Inherent in conventional HD (thrice-weekly) are two 48-hour short breaks (SIDP) and one 72-hour long break (LIDP) between HD sessions. OBJECTIVE: We used an implantable cardiac monitor (ICM) to define the incidence and timing of significant arrhythmias in an HD population. METHODS: Fifty CKD patients undergoing HD with left ventricular ejection fraction >35% had an ICM inserted, with intensive follow-up to record SCD events and predefined bradyarrhythmias and tachyarrhythmias. RESULTS: Mean age of the patients was 67 ± 11 years; 72% were male, and the mean follow-up was 18 ± 4 months. There were 8 unexpected SCDs (16%), all during the LIDP. The terminal event was severe bradycardia with asystole in each recorded case. No episodes of polymorphic ventricular tachycardia (VT) occurred. A total of 7686 arrhythmia events were recorded in 43 patients (86%), including bradycardia in 15 patients (30%), sinus arrest in 14 (28%), second-degree atrioventricular block in 4 (8%), nonsustained VT in 10 (20%), and new-onset paroxysmal atrial fibrillation in 14 (28%). The LIDP was the highest-risk period for all arrhythmias (P < .001). The arrhythmia event rate per hour was greatest during the first pre-HD period of the week compared with any other peri-HD period (P < .001). CONCLUSION: Risk of SCD and significant arrhythmias is greatest during the LIDP. SCD was attributable to severe bradycardia and asystole. Interventions to prevent this type of SCD or shorten the LIDP deserve further evaluation. CLINICAL TRIAL REGISTRATION INFORMATION: URL: https://www.anzctr.org.au (Unique identifier: ACTRN12613001326785).

High Incidence of Low Catheter-Tissue Contact Force at the Cavotricuspid Isthmus During Catheter Ablation of Atrial Flutter: Implications for Achieving Isthmus Block.

INTRODUCTION: Recurrent atrial flutter following cavotricuspid isthmus (CTI) ablation remains a significant problem. The prevalence of low contact force (CF) during CTI ablation using standard tools is unknown. Our aim was to characterize the prevalence of low CF applications when experienced operators performed CTI ablation using "traditional" markers of contact blinded to CF measurements. METHODS AND RESULTS: Average CF (grams, g) and force-time integral (FTI) was analyzed in 458 lesions in 17 patients undergoing CTI ablation. The isthmus was divided into the annular, mid and caval segments for region-specific analysis. Despite "good" contact using traditional markers, there was significant variability in CF within each isthmus segment (e.g., annular CTI 1-57 g). A high proportion of lesions had a CF <10 g (40%). Lowest CF was the annular (median 9 g), followed by the mid (12 g) and the caval CTI (18 g, P < 0.001). Sites of acute CTI re-connection had a lower average CF and FTI than nonreconnected sites (P < 0.05). Each 1 g increase in CF was associated with a 16% reduction in risk of recovered CTI conduction (95% confidence interval: 4-27%, P = 0.01). CONCLUSION: Use of surrogate markers of "good contact" during ablation by experienced operators in the absence of real-time CF sensing resulted in nearly half of all lesions being delivered with low CF with marked region-specific variability in CF. Low CF was implicated in longer time to achieve conduction block and increased risk of acute reconnection. These findings underscore the importance of real-time CF measurements for optimizing ablation of typical atrial flutter.

A minimal or maximal ablation strategy to achieve pulmonary vein isolation for paroxysmal atrial fibrillation: a prospective multi-centre randomized controlled trial (the Minimax study).

AIMS: Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation of atrial fibrillation (AF). The intervenous ridge (IVR) may be incorporated into ablation strategies to achieve PVI; however, randomized trials are lacking. We performed a randomized multi-centre international study to compare the outcomes of (i) circumferential antral PVI (CPVI) alone (minimal) vs. (ii) CPVI with IVR ablation to achieve individual PVI (maximal). METHODS AND RESULTS: Two hundred and thirty-four patients with paroxysmal AF underwent CPVI and were randomized to a minimal or maximal ablation strategy. The primary outcome of recurrent atrial arrhythmia was assessed with 7-day Holter monitoring at 6 and 12 months. PVI was achieved in all patients. Radiofrequency ablation time was longer in the maximal group (46.6 ± 14.6 vs. 41.5 ± 13.1 min; P < 0.01), with no significant differences in procedural or fluoroscopy times. At mean follow-up of 17 ± 8 months, there was no difference in freedom from AF after a single procedure between a minimal (70%) and maximal ablation strategy (62%; P = 0.25). In the minimal group, ablation was required on the IVR to achieve electrical isolation in 44%, and was associated with a significant reduction in freedom from AF (57%) compared with the minimal group without IVR ablation (80%; P < 0.01). CONCLUSION: There was no statistically significant difference in freedom from AF between a minimal and maximal ablation strategy. Despite attempts to achieve PVI with antral ablation, IVR ablation is commonly required. Patients in whom antral isolation can be achieved without IVR ablation have higher long-term freedom from AF (the Minimax study; ACTRN12610000863033).

The transesophageal echo probe may contribute to esophageal injury after catheter ablation for paroxysmal atrial fibrillation under general anesthesia: a preliminary observation.

INTRODUCTION: The transesophageal echo probe (TEE) is commonly used before and during atrial fibrillation (AF) ablation under general anesthesia (GA). We sought to determine the potential contribution of the TEE probe to esophageal injury after pulmonary vein isolation (PVI) alone for paroxysmal AF. METHODS AND RESULTS: Seventy-six patients undergoing PVI with TEE, PVI/TEE, 16 undergoing PVI without TEE (PVI/No TEE), and 27 undergoing TEE without any left atrial ablation (TEE/No LA ablation) under GA were included. Posterior wall ablation was power (20-25 W) and time limited (electrogram attenuation or ≤30 s). Esophageal capsule endoscopy (n = 206) was performed pre- and post-procedure and at 2 weeks. Esophageal lesions were seen in 30% of PVI/TEE, 0% of patients in the PVI/No TEE (P = 0.009), and 22% of TEE/No LA ablation groups (P = 0.47 vs. PVI/TEE). There were no instances of esophageal bleeding, perforation, or need for gastrointestinal intervention. Self-resolving dysphagia was the only reported symptom (5%). All lesions healed within 2 weeks. There was no significant difference in the location or morphological appearance of esophageal lesions seen in the PVI/TEE versus TEE/No LA ablation groups. CONCLUSIONS: Esophageal lesions were seen in 30% of patients undergoing PVI alone under GA with use of TEE and in a similar proportion (22%) of patients undergoing TEE in the absence of left atrial ablation. This study makes the preliminary observation that one must be cognizant of the TEE probe as a potential contributor to esophageal injury after AF ablation. Larger studies are needed to confirm these findings.

Tendencias en el uso de la ablación con catéter para el tratamiento de la fibrilación auricular versus el uso de la intervención coronaria para el tratamiento de la cardiopatía isquémica en Australia en los últimos diez años

Propósitos: los procedimientos de intervención coronaria percutánea (ICP) y la ablación con catéter son intervenciones terapéuticas bien aceptadas para el tratamiento de las coronariopatías y de la fibrilación auricular (FA), respectivamente. La intención de los autores fue examinar las tendencias temporales en la prestación de estos servicios en la última década en Australia. Métodos y resultados: la revisión retrospectiva de las cifras de las ICPs y las ablaciones en casos de FA desde 2000/01 a 2009/10 se hizo con base en información proveniente de tres fuentes: el Instituto Australiano de Salud, Bienestar y Tercera Edad (AIHW), la base de datos de Medicare Australia (MA), y los registros locales de un centro de referencia terciario de alto volumen (RMH) para ablación de la FA. Se ajustaron modelos de regresión lineal comparando las tendencias en número de procedimientos ajustados para la población en el curso de un período de diez años. Hubo un incremento de 5%/año ajustado para la población en los ICPs en el curso de diez años, tanto de la fuente de AIHW como de MA respectivamente (p<0,001). Esto fue similar a la tasa de crecimiento de todos los procedimientos cardiovasculares (AIHW: 5,1 versus 3,8%/año, p=0,27). Las ablaciones por FA mostraron un incremento de 30,9%, 23,2% y 39,8% por año ajustado para la población en el curso de diez años de las fuentes AIHW, MA, y RMH respectivamente (p<0,001 para todos). El crecimiento de las ablaciones por FA fue significativamente mayor que el de las ICPs (p<0,001 para las fuentes de AIHW y MA) y todos los procedimientos cardiovasculares (AIHW: 30,9%/año versus 3,8%/año, p<0,001). Conclusión: la realización de servicios de ablación con catéter en caso de FA en Australia ha aumentado de forma exponencial en el curso de la última década. Su tasa de crecimiento anual supera la de las ICPs y todos los procedimientos cardiovasculares. Dada la epidemia creciente de FA, estos datos tienen implicancias cruciales para las políticas de salud pública que evalúan la idoneidad de la infraestructura, la capacitación y la financiación de los servicios de ablación de la FA.

Catheter-tissue contact force determines atrial electrogram characteristics before and lesion efficacy after antral pulmonary vein isolation in humans.

INTRODUCTION: Electrogram (EGM) characteristics are used to infer catheter-tissue contact. We examined if (a) atrial EGM characteristics predicted CF and (b) compared the value of CF versus other surrogates for predicting lesion efficacy. METHODS AND RESULTS: Twelve paroxysmal AF patients underwent pulmonary vein isolation using radiofrequency (RF) ablation facilitated by a novel CF-sensing catheter. Operators were blinded to CF. EGM amplitude, width, and morphology were measured pre- and post-RF. At each RF site, average CF, force-time integral (FTI), impedance fall, time to impedance plateau, maximum power, catheter tip temperature, and total energy delivered were recorded. An effective lesion was defined based on previously validated EGM criteria for transmural lesions. There was a moderate correlation between CF and EGM amplitude (r = 0.19) and EGM width (r = -0.22). Pre-RF, EGM amplitude, and width had modest to poor discriminative capacity for identifying preablation CF (e.g., EGM amplitude identified CF>20 g with sensitivity and specificity of 67% and 60%, respectively). Preablation CF, FTI, and total energy delivered during RF were the only independent predictors of effective lesion formation. Neither pre-RF EGM amplitude/width nor power, temperature, and impedance changes during RF predicted effective lesion formation. An average CF >16 g or FTI >404 g*s had excellent sensitivity and specificity (>80%) for identifying an effective lesion. CONCLUSIONS: EGM characteristics do not reliably predict either CF before the onset of RF, nor do they predict the likelihood of an effective lesion. CF parameters were superior to power, temperature, and impedance changes during RF in predicting lesion efficacy.

Ten-year trends in the use of catheter ablation for treatment of atrial fibrillation vs. the use of coronary intervention for the treatment of ischaemic heart disease in Australia.

AIMS: Percutaneous coronary intervention (PCI) and catheter ablation are well-accepted therapeutic interventions for treatment of coronary artery disease and atrial fibrillation (AF), respectively. We sought to examine temporal trends in the provision of these services over the past decade in Australia. METHODS AND RESULTS: A retrospective review of the numbers of PCIs and AF ablations from 2000/01 to 2009/10 was performed on data from three sources: the Australian Institute of Health, Welfare and Aging (AIHW), Medicare Australia database (MA), and local records at a high volume tertiary referral centre (RMH) for AF ablation. Linear regression models were fitted comparing trends in population-adjusted procedural numbers over the 10-year period. There was a 5% per year population-adjusted increment in PCIs over 10 years from both the AIHW and MA sources, respectively (P < 0.001). This was similar to the growth rate of all cardiovascular procedures (AIHW: 5.1 vs. 3.8%/year, P = 0.27). Atrial fibrillation ablations showed a 30.9, 23.2, and 39.8% per year population-adjusted increment over 10 years from the AIHW, MA, and RMH sources respectively (P < 0.001 for all). Growth of AF ablations was significantly higher than PCIs (P < 0.001 for AIHW and MA sources) and all cardiovascular procedures (AIHW: 30.9 vs. 3.8%/year, P < 0.001). CONCLUSION: The provision of catheter-based AF ablation services in Australia has increased exponentially over the past decade. Its annual growth rate exceeded that of PCIs and all cardiovascular procedures. Given the increasing epidemic of AF, these data have critical implications for public health policy assessing the adequacy of infrastructure, training, and funding for AF ablation services.

Subtle post-procedural cognitive dysfunction after atrial fibrillation ablation.

OBJECTIVES: This study sought to determine whether post-operative neurocognitive dysfunction (POCD) occurs after ablation for atrial fibrillation (AF). BACKGROUND: Ablation for AF is a highly effective strategy; however, the risk of transient ischemic attack and stroke is approximately 0.5% to 1%. In addition, magnetic resonance imaging studies report a 7% to 14% prevalence of silent cerebral infarction. Whether cerebral ischemia results in POCD after ablation for AF is not well established. METHODS: The study included 150 patients; 60 patients undergoing ablation for paroxysmal atrial fibrillation (PAF), 30 patients undergoing ablation for persistent atrial fibrillation (PeAF), and 30 patients undergoing ablation for supraventricular tachycardia (SVT) were compared with a matched nonoperative control group of patients with AF awaiting radiofrequency ablation (n = 30). Eight neuropsychological tests were administered at baseline and at 2 days and 90 days post-operatively. The tests were administered at the same time points to the nonoperative control group. The reliable change index was used to calculate POCD. RESULTS: The prevalences of POCD at day 2 post-procedure were 28% in patients with PAF, 27% in patients with PeAF, 13% in patients with SVT, and 0% in control patients with AF (p = 0.007). At day 90, the prevalences of POCD were 13% in patients with PAF, 20% in patients with PeAF, 3% in patients with SVT, and 0% in control patients with AF (p = 0.03). When analyzing the 3 procedural groups together, 29 of 120 patients (24%) manifested POCD at day 2 and 15 of 120 patients (13%) at day 90 post-procedure (p = 0.029). On univariate analysis, increasing left atrial access time was associated with POCD at day 2 (p = 0.04) and day 90 (p = 0.03). CONCLUSIONS: Ablation for AF is associated with a 13% to 20% prevalence of POCD in patients with AF at long-term follow-up. These results were seen in a patient population with predominant CHADS2 (Congestive heart failure, Hypertension, Age ≥75 years, Diabetes mellitus, previous Stroke/transient ischemic attack) scores of 0 to 1, representing the majority of patients undergoing ablation for AF. The long-term implications of these subtle changes require further study.

Predictive value of impedance changes for real-time contact force measurements during catheter ablation of atrial arrhythmias in humans.

BACKGROUND: Catheter-tissue contact force (CF) determines radiofrequency (RF) ablation lesion size. Impedance changes during RF delivery are used as surrogate markers for CF. The relationship between impedance and real-time CF in humans remains unknown. OBJECTIVES: To determine whether impedance changes have predictive value for real-time CF during catheter ablation of atrial arrhythmias. METHODS: Real-time CF, force-time integral, and impedance were measured in 2265 RF lesions for atrial fibrillation or flutter in 34 patients. Operators were blinded to CF measurements. Impedance preablation, at 5-second intervals for 30 seconds after the RF onset, maximal impedance fall and time to impedance plateau during RF were correlated with CF. Average CF was divided into low (≤20 g), intermediate (21-60 g), and high (>60 g) categories. RESULTS: Preablation impedance poorly correlated with preablation CF (R = .07). Maximal impedance fall modestly correlated with average CF and force-time integral (R = .32 and .37, respectively). There was a large degree of overlap in impedance fall between different CF categories. A maximal impedance fall of 10 Ω could predict average CF of >20 g, with a sensitivity and specificity of 71% and 53% and a positive and negative predictive value of 51% and 49%, respectively. Impedance fall was only able to differentiate between different CF categories ≥15 seconds after the RF onset. Higher CFs moderately correlated with delayed plateau in impedance (R = .41). CONCLUSIONS: Impedance measurements (both baseline and impedance fall) are, at best, moderately efficacious as surrogate markers for predicting real-time catheter-tissue CF. These findings highlight the importance of real-time CF measurements, rather than impedance changes to optimize ablation efficacy.

Prospective characterization of catheter-tissue contact force at different anatomic sites during antral pulmonary vein isolation.

BACKGROUND: Catheter-tissue contact is critical for effective lesion creation. We characterized the contact force (CF) at different anatomic sites during antral pulmonary vein (PV) isolation for atrial fibrillation. METHODS AND RESULTS: Two experienced operators performed PV isolation in 22 patients facilitated by a novel CF-sensing ablation catheter in a blinded fashion. Average CF and force-time integral data from 1602 lesions were analyzed. The left and right PV antra were divided into the following: carina, superior, inferior, anterior, and posterior quadrants for analysis. There was significant variability in CF within and between different PV quadrants (P<0.05). Lowest CF of all left PV sites was at the carina and anterior quadrant, whereas highest CF was at the superior and inferior quadrants (P<0.05). Lowest CF of all right PV sites was at the carina, whereas highest CF was at the anterior and inferior quadrants (P<0.05). When comparing similar PV quadrants on the left versus right (eg, left carina versus right carina), CF was always higher in the right PVs (P<0.05), except at the superior quadrant where CF was similar in the left and right PVs (P=0.19). There was no specific pattern of anatomic distribution of excess CF (P=0.39). CONCLUSIONS: Monitoring of catheter-tissue CF during PV isolation demonstrates significant variability in CF within and between different PV antral sites. Sites of lowest CF were the carina and anterior left PVs and the carina of the right PVs. This information may be important for improving ablation efficacy and clinical outcomes during PV isolation.

Esophageal hematoma after atrial fibrillation ablation: incidence, clinical features, and sequelae of esophageal injury of a different sort.

BACKGROUND: Esophageal hematoma recently has been reported as a form of esophageal injury after atrial fibrillation (AF) ablation, attributed to the use of transesophageal echocardiography (TEE). We sought to determine the incidence, clinical features, and sequelae of this form of esophageal injury. METHODS AND RESULTS: This was a prospective series of 1110 AF ablation procedures performed under general anesthesia (GA) over 9 years. TEE was inserted after induction of GA to exclude left atrial appendage thrombus, define cardiac function, and guide transseptal puncture. The procedural incidence of esophageal hematoma was 0.27% (3/1110 procedures, mortality 0%). Odonyphagia, regurgitation, and hoarseness were the predominant symptoms, with an onset within 12 hours. There was absence of fever and neurological symptoms. Chest computed tomography excluded atrio-esophageal fistula and was diagnostic of esophageal hematoma localized to either the upper esophagus or extending the length of the mid and lower esophagus; endoscopy confirmed the diagnosis. Management was conservative in all cases comprising of ceasing oral intake and anticoagulation. Long term sequelae included esophageal stricture formation requiring dilatation, persistent esophageal dysmotility (mid esophageal hematoma), and vocal cord paralysis, resulting in hoarse voice (upper esophageal hematoma). CONCLUSIONS: Esophageal hematoma is a rare but important differential diagnosis for esophageal injury after TEE-guided AF ablation under GA, and can result in significant patient morbidity. Key clinical features differentiate presentation of esophageal hematoma from that of an atrio-esophageal fistula.

Impact of collimation on radiation exposure during interventional electrophysiology.

AIMS: Fluoroscopy remains a cornerstone imaging technique in contemporary electrophysiology practice. We evaluated the impact of collimation to the 'minimal required field size' on clinically significant parameters of radiation exposure. METHODS AND RESULTS: Radiation dose measured by dose area product (DAP) and radiation dose rate measured by DAP per minute of fluoroscopy were determined for all 571 electrophysiology procedures performed in a single electrophysiology laboratory from January 2010 to December 2010. Data from 205 procedures performed by one interventional electrophysiologist, who instituted a practice of routinely collimating to the minimum required visual fluoroscopy field on a case-by-case basis, were compared with data from 366 procedures performed by the three other experienced interventional electrophysiologists using the laboratory who continued their existing practice of ad hoc collimation. Significant reductions in radiation exposure were seen with the practice of routine maximal collimation. The largest reductions were seen during 'simple' ablation procedures. CONCLUSION: A practice of routinely collimating to the minimum required visual fluoroscopy field results in significant reductions in radiation exposure when compared with a usual approach to collimation. This may have important implications for risk of malignancy in patients and operators.

Effect of respiration on catheter-tissue contact force during ablation of atrial arrhythmias.

BACKGROUND: Catheter-tissue contact is important for effective lesion creation. OBJECTIVE: To assess the effect of respiration on contact force (CF) during atrial fibrillation and cavotricuspid isthmus (CTI)-dependent atrial flutter ablation. METHODS: Patients undergoing CTI ablation alone (n = 15) and pulmonary vein (PV) isolation alone (n = 12) under general anesthesia were recruited. Lesions were delivered under ventilation (30 seconds) alternating with lesions delivered under apnea (30 seconds) at an adjacent anatomical site at CTI or PV antra. The average force (F(av)), force-time integral (FTI), and force variability were measured in a region-specific manner by using a novel CF-sensing ablation catheter. Operators were blinded to CF data. RESULTS: F(av) and FTI were higher with apnea than with ventilation in all CTI and PV segments (P <.05), an effect attributed to drop in CF with each respiratory swing, resulting in greater force variability during ventilation (P <.05). Low FTI lesions (<500 g) were strongly associated with longer ablation time to achieve bidirectional CTI block (r(2) = .81; P <.001), left PVI (r(2) = .65; P = .009), and right PVI (r(2) = .41; P = .05). Sites with transient CTI block were associated with lower F(av) and FTI than were sites with persistent CTI block (P <.05). Sites of acute PV reconnection were associated with lower F(av) and FTI compared with non-reconnected sites (P <.001). CONCLUSIONS: Catheter-tissue CF is critically influenced by respiration; greater CF is observed with ablation during apnea. Poor CF is implicated in longer ablation time to achieve CTI block or PV isolation and in acute reconnection.

Long-term outcome following ablation of atrial flutter occurring late after atrial septal defect repair.

AIMS: In patients with surgical atrial septal defect (ASD) repair, late atrial flutters (AFLs), including cavotricuspid isthmus (CTI)-dependent and non-CTI-dependent scar-related flutter (AFL), are common. Radiofrequency ablation (RFA) of these arrhythmias has a high acute success rate. We aimed to characterize the long-term freedom from atrial arrhythmias in this population. METHODS: Twenty consecutive patients undergoing RFA for AFL late after ASD repair were included. Electrophysiological assessment included multipolar activation, entrainment, and electroanatomic mapping. Clinical, electrocardiograph, and Holter monitoring follow-up was conducted every 6 months. RESULTS: Mean age was 53 ± 13 years. Time from surgical repair to RFA was 29 ± 15 years. All patients had CTI-dependent AFL (20/20). There were 1.6 ± 0.7 arrhythmias per patient; other arrhythmias included non-CTI-dependent AFL (14), focal atrial tachycardia (two), and atrioventricular nodal reentry tachycardia (two) . Acute success was obtained in 100%. Five patients with recurrent AFL (three CTI dependent, two non-CTI dependent) at 13 ± 8 months had successful repeat RFA. At 3.2 ± 1.6 years follow-up since the last procedure, 90% of patients with successful RFA for AFL remained free of their clinical arrhythmia. However, 30% of the original 20 patients had documented atrial fibrillation (AF) 2.1 ± 1.6 years after the last procedure; five (25%) required AF intervention. One stroke (5%) occurred in the context of late AF. CONCLUSION: RFA of AFL occurring late after surgical ASD repair has a low long-term risk of recurrence, although 25% of patients required two procedures. However, there is a high late incidence of AF (30%), with an additional 25% of patients requiring intervention for AF.

Low risk of major complications associated with pulmonary vein antral isolation for atrial fibrillation: results of 500 consecutive ablation procedures in patients with low prevalence of structural heart disease from a single center.

OBJECTIVES: To report the major complication rate associated with pulmonary vein antral isolation (PVAI) in a consecutive series of 500 patients from a single center. BACKGROUND: Catheter ablation for atrial fibrillation (AF) is an established procedure for refractory AF. However, the risk of major complications has been reported to range from 3.9% to 4.5% and continues to represent a cause for concern. We hypothesized that these studies may have overestimated the rate of major complications associated with PVAI in patients with a low prevalence of structural heart disease (SHD). METHODS: Data were prospectively collected from 500 consecutive AF ablation procedures on 424 patients (mean age 55 ± 11 years, 79% men, paroxysmal AF-80% and persistent AF-20%, CHADS2 scores of 0, 1, 2, 3 present in 64%, 28%, 7%, 1%, respectively), performed between July 2006 and September 2009. All procedures were performed under general anesthesia with intraoperative transesophageal echo. PVAI was performed using a nonfluoroscopic mapping system with an endpoint of PV isolation. Adjunctive left atrial ablation was performed in 21% of patients only. Major complications were defined from a compilation of those reported in 5 prior studies reporting complications. RESULTS: In 500 procedures, there were no instances of death, stroke/TIA, cardiac tamponade, atrioesophageal fistula, or PV stenosis. Major complications occurred in 4 procedures (0.8%): esophageal hematoma (TEE probe)--2; pharyngeal trauma--1; and retroperitoneal hematoma-1. CONCLUSIONS: AF ablation can be performed safely in young patients without structural heart disease with a low risk (<1%) of major complications when using a strategy of PVAI.

Long-term outcome following successful catheter ablation of atrial tachycardia originating from the pulmonary veins: absence of late atrial fibrillation.

OBJECTIVES: This study aimed to characterize the long-term outcome and incidence of atrial fibrillation (AF) in patients following catheter ablation of focal atrial tachycardia (AT) from the pulmonary veins (PV). BACKGROUND: Although both AT and AF may originate from ectopic foci within PVs, it is unknown whether PV AT patients subsequently develop AF. METHODS: Twenty-eight patients with 29 PV ATs (14%) from a consecutive series of 194 patients who underwent RFA for focal AT were included. Patients with concomitant AF prior to the index procedure were excluded. RESULTS: The minimum follow-up duration was 4 years; mean age 38 +/- 18 years with symptoms for 6.5 +/- 10 years, having tried 1.5 +/- 0.9 antiarrhythmic drugs. The distribution of foci was: left superior 12 (41%), right superior 10 (34%), left inferior 5 (17%), and right inferior 2 (7%). The focus was ostial in 93% and 2-4 cm distally within the vein in 7%. Mean tachycardia cycle length was 364 +/- 90 ms. Focal ablation was performed in 25 of 28 patients. There were 6 recurrences with 5 from the original site. Twenty-six patients were available for long-term clinical follow-up. At a mean of 7.2 +/- 2.1 years, 25 of 26 (96%) were free from recurrence off antiarrhythmic drugs. No patients developed AF. CONCLUSIONS: Focal ablation for tachycardia originating from the PVs is associated with long-term freedom from both AT and AF. Therefore, although PV AT and PV AF share a common anatomic distribution, PV AT is a distinct clinical entity successfully treated with focal RFA and not associated with AF in the long term.

Vagal paroxysmal atrial fibrillation: prevalence and ablation outcome in patients without structural heart disease.

INTRODUCTION: The prevalence of vagal and adrenergic atrial fibrillation (AF) and the success rate of pulmonary vein isolation (PVI) are not well defined. We investigated the prevalence of vagal and adrenergic AF and the ablation success rate of antral pulmonary vein isolation (APVI) in patients with these triggers compared with patients with random AF. METHODS AND RESULTS: Two hundred and nine consecutive patients underwent APVI due to symptomatic drug refractory paroxysmal AF. Patients were diagnosed as vagal or adrenergic AF if >90% of AF episodes were related to vagal or adrenergic triggers; otherwise, a diagnosis of random AF was made. Clinical, electrocardiogram (ECG), and Holter follow-up was every 3 months in the first year and every 6 months afterward and for symptoms. Of 209 patients, 57 (27%) had vagal AF, 14 (7%) adrenergic AF, and 138 (66%) random AF. Vagal triggers were sleep (96.4%), postprandial (96.4%), late post-exercise (51%), cold stimulus (20%), coughing (7%), and swallowing (2%). At APVI, 94.3% of patients had isolation of all veins. Twenty-five (12%) patients had a second APVI. At a follow-up of 21 +/- 15 months, the percentage of patients free of AF was 75% in the vagal group, 86% in the adrenergic group, and 82% for random AF (P = 0.51). CONCLUSION: In patients with PAF and no structural heart disease referred for APVI, vagal AF is present in approximately one quarter. APVI is equally effective in patients with vagal AF as in adrenergic and random AF.