Cardiac Surgery for Arrhythmias

Cost-Effectiveness and Budget Impact Analysis of Apixaban and Rivaroxaban Versus Warfarin in the Prevention of Stroke in Patients With Non-Valvular Atrial Fibrillation (NVAF) in Iran

INTRODUCTION

This study evaluates the cost-effectiveness of Apixaban and Rivaroxaban, compared to Warfarin, for stroke prevention in patients with non-valvular atrial fibrillation in Iran.

METHOD

A Markov model with a 30-year time horizon was employed to simulate and assess different treatment strategies' cost-effectiveness. The study population comprised Iranian adults with NVAF, identified through specialist consultations, hospital visits, and archival record reviews. Direct medical costs, direct nonmedical, and indirect costs were included. Quality-adjusted life years (QALY) were assessed using an EQ-5D questionnaire. This study utilized a cost-effectiveness threshold of $11 134 per QALY.

RESULTS

Apixaban demonstrated superior cost-effectiveness compared to Rivaroxaban and Warfarin. Over 30 years, total costs were lower in the Apixaban and Rivaroxaban groups compared to the Warfarin group ($126.18 and $109.99 vs. $150.49). However, Apixaban showed higher total QALYs gained compared to others (0.134 vs. 0.133 and 0.116). The incremental cost-effectiveness ratio for comparing Apixaban to Warfarin was calculated at -1332.83 cost per QALY, below the threshold of $11 134, indicating Apixaban's cost-effectiveness. Sensitivity analyses confirmed the robustness of the findings, with ICER consistently remaining below the threshold. Over 5 years (2024-2028) of Apixaban usage, the incremental cost starts at USD 70 250 296 in the first year and gradually rises to USD 71 770 662 in the fifth year. DSA and PSA were assessed to prove the robustness of the results.

CONCLUSION

This study shows that Apixaban is a cost-effective option for stroke prevention in non-valvular atrial fibrillation patients in Iran compared to Warfarin.

Area Available for Atrial Fibrillation to Propagate Is an Important Determinant of Recurrence After Ablation

OBJECTIVES

This study sought to evaluate atrial fibrillation (AF) ablation outcomes based on scar patterns and contiguous area available for AF wavefronts to propagate.

BACKGROUND

The relevance of ablation scar pattern acting as a barrier for electrical propagation in recurrence after catheter ablation for persistent AF is unknown.

METHODS

Three-month post-ablation atrial cardiac magnetic resonance was used to determine post-ablation scar. The left atrium (LA) was divided into 5 areas based on anatomical landmarks and scar patterns. The length of gaps in scar on the area boundaries was used to calculate fibrillatory areas (FAs) by adding the weighted contribution of adjacent areas. Cylindrical as well as patient-specific computational models were used to further confirm findings.

RESULTS

A total of 75 patients that underwent an initial ablation for AF with 2 years of follow-up were included. The average maximum FA was 7,896 ± 1,988 mm² in patients with recurrence (n = 40) and 6,559 ± 1,784 mm² in patients without recurrence (n = 35) (p < 0.008). After redo ablation in 19 patients with recurrence, average maximum FA was 7,807 ± 1,392 mm² in 9 patients with recurrence and 5,030 ± 1,765 mm² in 10 without recurrence (p < 0.007). LA volume and total scar were not significant predictors of recurrence after the first ablation. In the cylindrical model, AF self-terminated after reducing the FAs. In the patient-specific models, simulation matched the clinical outcomes with larger FAs associated with post-ablation arrhythmia recurrences.

CONCLUSIONS

This data provides mechanistic insights into AF recurrence, suggesting that post-ablation scar pattern dividing the atria into smaller regions is an important and better predictor than LA volume and total scar, with improved long-term outcomes in persistent AF.

Outcomes of Atrial Arrhythmia Surgery in Patients With Congenital Heart Disease: A Systematic Review

Background The improved life expectancy of patients with congenital heart disease is often accompanied by the development of atrial tachyarrhythmias. Similarly, the number of patients requiring redo operations is expected to continue to rise as these patients are aging. Consequently, the role of arrhythmia surgery in the treatment of atrial arrhythmias is likely to become more important in this population. Although atrial arrhythmia surgery is a well-established part of Fontan conversion procedures, evidence-based recommendations for arrhythmia surgery for macroreentrant atrial tachycardia and atrial fibrillation in other patients with congenital heart disease are still lacking. Methods and Results Twenty-eight studies were included in this systematic review. The median reported arrhythmia recurrence was 13% (interquartile range, 4%-26%) during follow-up ranging from 3 months to 15.2 years. A large variation in surgical techniques was observed. Based on the acquired data, biatrial lesions are more effective in the treatment of atrial fibrillation than exclusive right-sided lesions. Right-sided lesions may be more appropriate in the treatment of macroreentrant atrial tachycardia; evidence for the superiority of additional left-sided lesions is lacking. There are not enough data to support the use of exclusive left-sided lesions. Theoretically, prophylactic atrial arrhythmia surgery may be beneficial in this population, but evidence is currently limited. Conclusions To be able to provide recommendations for arrhythmia surgery in patients with congenital heart disease, future studies should report outcomes according to the type of preoperative arrhythmia, underlying congenital heart disease, lesion set, and energy source. This is essential for determining which surgical techniques should ideally be applied under which circumstances.

The Role of Collaboration Between Electrophysiologists and Surgeons in the Management of Complex Arrhythmia Patients

Although the need for surgery in patients with arrhythmias has declined in the past several decades due to the emergence of catheter ablation, there is still room for collaboration between electrophysiologists and surgeons, mainly when managing patients with atrial fibrillation, ventricular tachycardia, and cardiac implantable electronic devices.

A New Method for Direct Three-Dimensional Measurement of Left Atrial Appendage Dimensions during Transesophageal Echocardiography

AIMS

Currently, two-dimensional transesophageal echocardiography (2DTEE) at a cut-plane angulation of 135° is the recommended method to size maximal left atrial appendage (LAA) orifice diameter before introducing a percutaneous LAA closure device. We compared real time three-dimensional TEE (RT3DTEE) and 2DTEE for measuring LAA dimensions versus computed tomography (CT) as gold standard.

METHODS AND RESULTS

We prospectively studied 30 consecutive patients who underwent a routine TEE examination, using QLAB 10.0 Application on EPIQ7 iE33 3D echo machine between December 2012 and December 2013. All patients underwent 64-slice CT before pulmonary vein isolation or for workup of pulmonary embolism. LAA measurements were compared between 135 2DTEE and RT3DTEE. Results were compared with CT measurements. Using RT3DTEE, larger LAA diameters were measured versus 2DTEE (23.5 ± 3.9 vs. 24.5 ± 4.7 mm). In seven patients (23.3%), the measurements in 135° 2DTEE were smaller than the cut-plane angulation with maximal orifice diameter. RT3DTEE measurements of LAA were not different from CT regarding number of lobes, area of orifice, and maximal diameter. LAA volume could not be measured directly using RT3DTEE. No difference was found between LAA depth using RT3DTEE (19.5 ± 2.3 mm) vs. CT (19.6 ± 2.3, P = NS) and 2DTEE (19.4 ± 2.2 mm) vs. CT (P = NS). However, RT3DTEE (24.5 ± 4.7 mm) vs. CT (24.6 ± 5, P = NS) was more accurate in measuring maximal LAA diameter compared to 2DTEE (23.5 ± 3.9 mm) vs. CT (P < 0.01).

CONCLUSION

RT3DTEE method is more accurate than 2DTEE for assessment of maximal LAA orifice diameter. Bedsides, RT3DTEE LAA measurements are not statistically different from CT. Thus, RT3DTEE may facilitate LAA closure procedure by choosing the appropriate device size.

Position of totally thoracoscopic surgical ablation in the treatment of atrial fibrillation: an alternative method of conduction testing

Recent advances in surgical techniques and understanding of the pathophysiology of atrial fibrillation has led to the development of a less invasive thoracoscopic surgical treatment including video-assisted bilateral pulmonary vein isolation using bipolar radiofrequency ablation clamps. More recently, the same operation became possible via a totally thoracoscopic approach.

In this paper we describe technical aspects of the thoracoscopic approach to surgical treatment of AF and discuss its features, benefits and limitations. Furthermore, we present a new alternative technique of conduction testing using endoscopic multi-electrode recording catheters.

An alternative electrophysiological mapping strategy involves a multi-electrode recording catheter designed primarily for percutaneous endocardial electrophysiologic mapping procedure. According to our initial experience, the recordings obtained from the multi-electrode catheters positioned around the pulmonary veins are more accurate than the recordings obtained from the multifunctional ablation and pacing pen.

The totally thoracoscopic surgical ablation approach is a feasible and efficient treatment strategy for atrial fibrillation. The conduction testing can be easily and rapidly performed using a multifunctional pen or multi-electrode recording catheter.

Rhythm course over 5 years following surgical ablation for atrial fibrillation

OBJECTIVES

Reporting methods for surgical ablation (SA) of atrial fibrillation (AF) were standardized by the Heart Rhythm Society Guidelines, stating that results should be reported only for the first 2 years following SA. The purpose of this study was to assess the outcome of SA over 5 years and determine predictors for success over that period.

METHODS

Data were collected prospectively for all SA (n=787). Rhythm was verified by electrocardiogram and Holter monitoring at 3, 6, 9, 12, 18 and 24 months and yearly thereafter. Patients with rhythm status available at 2 and 5 years were included in the main analyses (n=137). Multivariate logistic regression was used for predictors of normal sinus rhythm (NSR). Receiver operating curves compared 2- and 5-year predicted probability against observed rhythm status by year.

RESULTS

Return to NSR at 2 years was 88% (80% off antiarrhythmic drugs) and at 5 years was 85% (71% off antiarrhythmic drugs). The majority of patients (64%) had stable NSR over 5 years. The only predictor for 2-year NSR was smaller left atrial size (odds ratio [OR]=0.40, P=0.044). Predictors for 5-year NSR were smaller left atrial size (OR=0.28, P=0.002), age (OR=0.91, P=0.031) and length of hospital stay (OR=0.85, P=0.026).

CONCLUSIONS

This study demonstrated stable results of SA for AF over time with somewhat different predictors for 2- and 5-year NSR in a group of patients with complete follow-up at both time points. Accurate models to determine predictors for success of SA more than 2 years after surgery are essential to better understand long-term outcome for patients with AF.

[Surgical closure of the left atrial appendage in patients with atrial fibrillation. Indications, techniques and results]

Cardiac embolisation in patients with atrial fibrillation accounts for the most serious complication of cerebral infarction. The left atrial appendage resembles the origin of these cardiac emboli in the majority of cases, although other anatomical areas of the left atrium might also be prerequisites for thrombus formation. Surgical closure of the left atrial appendage during an ablation therapy incorporates the theoretical possibility of reducing the rate of cardiac cerebral infarction. In order to achieve closure, different surgical strategies exist: either exclusion by over-sewing or snaring or excision by using scissors or a stapling device. All therapies incorporate pros and cons. One of the major complications and most feared side-effect is the recanalisation of a formerly closed left atrial appendage, especially in a thrombus filled left atrial appendage cavity. But also reopening of the formerly closed orificium and still existing remnants with communication to the left atrium might stand for an increased risk. Due to the good results of left atrial appendage excision, this surgical therapy at the moment presents the surgical gold standard, as this therapy is recommended in the updated ESC guidelines for the management of atrial fibrillation. If excision of the left atrial appendage will reduce the risk of cardiac embolisation needs to be examined in large prospective-randomized trials with a controlled systemic follow-up. So far, excision of the left atrial appendage as an alternative to oral anticoagulation, especially in patients with atrial fibrillation, is not recommended.

A flash from the past: a case on long term follow-up of a "corridor" operation

An electrophysiological study in a patient with a previous corridor operation was performed because of syncope. The atrial electrograms showed the persistence of the sinus rhythm in the right atrial corridor despite an organized atrial fibrillation in the left atrium. The first case described of a long term follow-up in a corridor operation, one of the first described surgical approach for the treatment of atrial fibrillation, that gave the beginning to the non-pharmacological approach of this arrhythmia.

Computational mapping identifies localized mechanisms for ablation of atrial fibrillation

Atrial fibrillation (AF) is the most common heart rhythm disorder in the Western world and a common cause of hospitalization and death. Pharmacologic and non-pharmacologic therapies have met with limited success, in part due to an incomplete understanding of the underlying mechanisms for AF. AF is traditionally characterized by spatiotemporally disorganized electrical activation and, although initiating triggers for AF are described, it is unclear whether AF is sustained by spatially meandering continuous excitation (re-entrant waves), localized electrical sources within the atria, or some other mechanism. This has limited therapeutic options for this condition. Here we show that human AF is predominantly caused by a small number (1.8 ± 0.9) of localized re-entrant waves or repetitive focal beats, that remain stable with limited spatial migration over prolonged periods of time. Radiofrequency ablation that selectively targeted the sites of these sources was able to immediately terminate fibrillation and eliminate the arrhythmia with high success. Our results show that human AF, despite apparent spatiotemporal disorganization, is often perpetuated by a few spatially-constrained and temporally conserved sources whose targeted ablation can eliminate this complex rhythm disorder.

Designing comparative effectiveness trials of surgical ablation for atrial fibrillation: experience of the Cardiothoracic Surgical Trials Network

OBJECTIVE

Since the introduction of the cut-and-sew Cox maze procedure for atrial fibrillation, there has been substantial innovation in techniques for ablation. Use of alternative energy sources for ablation simplified the procedure and has resulted in dramatic increase in the number of patients with atrial fibrillation treated by surgical ablation. Despite its increasingly widespread adoption, there is lack of rigorous clinical evidence to establish this procedure as an effective clinical therapy.

METHODS

This article describes a comparative effectiveness randomized trial, supported by the Cardiothoracic Surgical Clinical Trials Network, of surgical ablation with left atrial appendage closure versus left atrial appendage closure alone in patients with persistent and long-standing persistent atrial fibrillation undergoing mitral valve surgery. Nested within this trial is a further randomized comparison of 2 different lesions sets: pulmonary vein isolation and the full maze lesion set.

RESULTS

This article addresses trial design challenges, including how best to characterize the target population, operationalize freedom from atrial fibrillation as a primary end point, account for the impact of antiarrhythmic drugs, and measure and analyze secondary end points, such as postoperative atrial fibrillation load.

CONCLUSIONS

This article concludes by discussing how insights that emerge from this trial may affect surgical practice and guide future research in this area.

Catheter ablation for ventricular tachycardia

Sudden cardiac death due to ventricular arrhythmias remains the most common cause of death in developed nations. Implantable cardioverter defibrillators have been shown to improve mortality in high-risk groups for ventricular tachyarrhythmias, but they are not curative, with the risk of arrhythmia recurrence remaining unaltered. It is also important to remember that ventricular tachycardia (VT) in the setting of a structurally normal heart is often not associated with an increased risk of sudden death and catheter ablation is a potentially curative procedure in this cohort. Recent advances in catheter ablation for VT have increased the efficacy in creating adequate lesions, accurate three-dimensional maps and mapping haemodynamically unstable VT, all of which have increased the utility of this modality in the treatment of ventricular arrhythmias. In this article, we review the recent advances that have fuelled renewed interest in catheter ablation of VT, its clinical utility and who should be referred.

Atrial fibrillation in the elderly

Atrial fibrillation (AF) remains the most common form of cardiac arrhythmia seen in man, and often requires acute intervention. This article provides an overview of the incidence, prevalence, etiology, and pathophysiology of AF in elderly patients, with special emphasis on the perioperative period. The pharmacologic and nonpharmacologic management strategies available to the anesthesiologist are described. The anesthesiologist must be aware of the causes, consequences, and treatment of elderly patients developing AF during the perioperative period, as well as patients presenting to the operating room with chronic AF.

Long-term results after ablation for long-standing atrial fibrillation concomitant to surgery for organic heart disease: is microwave energy reliable?

OBJECTIVE

Microwave ablation has been reported as efficient for the surgical treatment of long-standing atrial fibrillation. However, the influence of ablation lesions on long-term results is not known.

METHODS

From August of 2000 to November of 2003, 41 patients underwent a left atrial endocardial microwave ablation procedure after a Cox-Maze-like lesion set for long-standing atrial fibrillation concomitant to surgery for valvular or coronary artery disease. Mitral valve surgery alone or combined was performed in 31 cases (75.6%). The mean diameter of the left atrium was 7.19 +/- 1.44 cm. The mean duration of preoperative atrial fibrillation was 4.7 +/- 3.6 years. Patient follow-up was conducted by means of direct clinical examination, electrocardiography, and transthoracic echocardiography. The mean follow-up was 5.37 +/- 0.91 years.

RESULTS

Patient follow-up was achieved in 82% of cases (n = 28). Seven patients (17%) died during follow-up. Stroke was the cause of death in 1 patient with persistence of atrial fibrillation. Major complications occurred in 4 (14.3%) of the patients that were related to the persistence of atrial fibrillation. At 5 years follow-up, 39.3% of patients (11/28) were in sinus rhythm. Seventeen patients (60.7%) were in New York Heart Association classes I and II, and 11 patients (39.3%) were in New York Heart Association class III at the time of follow-up.

CONCLUSION

In our experience, left atrial endocardial microwave ablation for long-standing atrial fibrillation after a Cox-Maze-like ablation lesion set during surgery for organic heart disease is not a reliable method of achieving long-term conversion to sinus rhythm.

The ambiguous pulmonary venoatrial junction: a new perspective

PURPOSE

The pulmonary venoatrial junction (PVAJ) has recently received attention due to the widespread use of catheter ablation for atrial fibrillation. However, the literature lacks a consensus in the definition of the PVAJ. We aim to review the inconsistent definitions for the PVAJ and related implications in imaging and catheter ablation for atrial fibrillation.

RESULTS

The PVAJ as described by embryology, gross anatomy, histology and imaging is ambiguous, leading to disparities in its definition. Because of differing definitions of the PVAJ, there is a broad range in the prevalence of anatomic variations, including (1) percentage of common pulmonary veins (10-79% on the left), (2) supernumerary pulmonary veins (10-42%) and (3) ostial diameter and shape. We postulate several reasons for this broad range in the described prevalence of anatomic variation of the PV as follows: (1) different definitions of the PVAJ, (2) different vantage points, (3) different imaging modalities, and (4) different prevalence of anatomic variants among different study populations.

CONCLUSIONS

The ambiguous PVAJ with its gradual transition from the left atrium to the pulmonary veins defies precise definition even though it plays an important role in the management of atrial fibrillation. Physicians should be aware of variability in the language used to describe the PVAJ and resultant discrepancy in reported anatomical information.

Surgery for ventricular tachycardia in patients undergoing surgical ventricular restoration: The Karolinska approach

This article presents a review on the efficacy of surgical ventricular restoration and direct surgery for ventricular tachycardia in patients with left ventricular aneurysm or dilated ischemic cardiomyopathy. The procedure includes a non-electrophysiologically guided subtotal endocardiectomy and cryoablation in addition to endoventricular patch plasty of the left ventricle. Coronary artery bypass surgery and mitral valve repair are performed concomitantly as needed. In our experience, this procedure yielded a 90% success rate in terms of freedom from spontaneous ventricular tachycardia, with an early mortality rate of 3.8%. A practical guide to the pre- and postoperative management of these patients is provided.

Management of atrial fibrillation

Atrial fibrillation is the most common sustained cardiac rhythm disorder, and confers a substantial mortality and morbidity from stroke, thromboembolism, heart failure, and impaired quality of life. With the increasingly elderly population in the developed world, as well as improvements in the management of myocardial infarction and heart failure, the prevalence of atrial fibrillation is increasing, resulting in a major public-health problem. This Review aims to provide an overview on the modern management of atrial fibrillation, with particular emphasis on pharmacological and non-pharmacological approaches. Irrespective of a rate-control or rhythm-control strategy, stroke prevention with appropriate thromboprophylaxis still remains central to the management of this common arrhythmia. Electrophysiological approaches could hold some promise for a curative approach in atrial fibrillation.

Beating heart direct left atrial access balloon cryoablation: safety and efficacy of pulmonary vein isolation in an ovine model

OBJECTIVE

: Clinical experience with endocardial cryoablation for the surgical treatment of atrial fibrillation has demonstrated safety and efficacy. Direct access to the left atrium via a thoracoscopic or pericardial approach with a balloon-tipped cryoablation catheter might facilitate endocardial cryoablation on the beating heart. We investigated the ability of a novel cryoballoon to produce endocardial pulmonary vein ostial cryolesions on the beating heart in a large-animal model.

METHODS

: Six sheep underwent small left thoracotomy. A 10.5F catheter with a 23-mm cryoballoon was inserted directly into the left atrium under fluoroscopic and intracardiac echo (ICE) guidance. Cryoablation of the pulmonary vein ostia was performed. Animals were killed at 14 days. Pulmonary venous electrical isolation was assessed immediately before the animals were killed.

RESULTS

: All animals survived balloon cryoablation with no periprocedural complications. Balloon occlusion was well tolerated hemodynamically, with minimal change in blood pressure (-4 ± 6 mm Hg systolic BP) and no change in heart rate. ICE demonstrated an absence of intracardiac air or ice embolization during ablation. Mean balloon temperature was -67 ± 8°C. All animals were neurologically intact after the procedure. Five of 6 (83%) veins exhibited circumferential exit block. Phrenic nerve function was intact in all animals. On gross inspection, all lesions were circumferential and continuous without evidence of endocardial thrombus. Pathology confirmed circumferential transmurality in all treated veins.

CONCLUSIONS

: Direct left atrial access cryoballoon ablation was effective for isolating pulmonary veins. This technology may be an important component of a minimally invasive beating heart CryoMaze procedure for the treatment of atrial fibrillation.

Transcatheter cryoablation with 3-D mapping of an atrial ectopic tachycardia in a pediatric patient with tachycardia induced heart failure

Atrial ectopic tachycardias (AET) are often resistant to medical management and can lead to a significant reduction in cardiac function. Transcatheter cryoablation, a definitive therapy, to our knowledge has yet to be described in the pediatric population. A three-year-old male presented with AET induced heart failure which persisted despite medical management. Management was complicated by worsening heart failure and propylene glycol intoxication. He underwent transcatheter cryoablation using a 3-D navigation system with an initially successful elimination of the arrhythmia. After a late recurrence (15 months) of the AET he underwent epicardial transcatheter ablation using cryotherapy with successful elimination of the arrhythmia.

Current strategies in the surgical treatment of atrial fibrillation: review of the literature and Onze Lieve Vrouw Clinic's strategy

Atrial fibrillation is the most common rhythm disturbance in clinical practice. It is a major source of stroke and morbidity. Although the Cox maze procedure effectively eliminates atrial fibrillation in most patients, the procedure has not found widespread application. As a consequence, new operations that use alternative sources of energy, such as radiofrequency, microwave, cryothermy, laser, and ultrasound have emerged to surgically create lesion sets to treat atrial fibrillation. This article reviews the fundamentals and current strategies in the surgical treatment of atrial fibrillation.

Spatial and temporal stability of the dominant frequency of activation in human atrial fibrillation

PURPOSE

Intraoperative activation sequence mapping during atrial fibrillation (AF) is difficult because of the complexity of the data. The data analysis is time consuming, and picking activation times can be ambiguous. The purpose of this study was to determine whether mapping in the frequency domain during AF can be used to rapidly locate the region and assess the stability of the dominant frequency.

METHODS

In 33 patients, epicardial bipolar electrograms were intraoperatively recorded from 250 sites during AF. For each electrogram, a power spectrum was calculated using a fast Fourier transform. The peak frequency below 11 Hz was determined from the power spectrum for each electrogram.

RESULTS

Isofrequency mapping demonstrated that 91% of the patients exhibited a distinct region of maximum (dominant) frequency at least once during the recording period. Nine percent had no distinct region of dominant frequency. A distinct region of stable dominant frequency was located in the left atrium 30% of the time and the right atrium 12% of the time for the entire recording period. The location of dominant frequency changed during the recording period in 48% of the patients. The dominant frequency was highest in patients with chronic AF (8.29 +/- 1.0 Hz) compared to those with paroxysmal AF (PAF) (6.54 +/- 0.62 Hz, P = .001). The dispersion of frequency was higher in the patients with persistent AF (1.03 +/- 0.4 Hz) than in those with PAF (0.6 +/- 0.3 Hz, P < .001).

CONCLUSION

Frequency mapping rapidly and accurately identifies the region of dominant activation frequency. The frequency is faster and more variable in persistent AF than in PAF. The location of the dominant frequency was unstable, changing during the recording period, in half the patients. The location of the dominant frequency was independent of the type of AF.

Electroanatomic Characteristics of Atrial Premature Beats Triggering Atrial Fibrillation in Patients with Persistent Versus Paroxysmal Atrial Fibrillation

APBs in Persistent Versus Paroxysmal AF.

BACKGROUND

Although the electrical disconnection between the left atrium (LA) and pulmonary veins (PVs) by radiofrequency catheter ablation has been proven to be effective in controlling atrial fibrillation (AF), the recurrence rate is higher in patients with persistent AF (PeAF) than with paroxysmal AF (PAF). We hypothesized that the origin of the atrial premature beats (APBs) that trigger AF and the pattern of their breakthrough into the LA differ between PAF and PeAF.

METHODS

We mapped 75 APBs (53 APBs triggering AF, 22 isolated APBs) from the LA and PVs in 26 patients with AF (age: 49.5 +/- 9.6, males: 23, PAF = 17, PeAF = 9), using a noncontact endocardial mapping (NCM) system. The location of the preferential conduction (PC) sites and their conduction velocity (CV) were compared.

RESULTS

In patients with PeAF, the earliest activation (EA) site and exit of the PC were more frequently located on the LA side of the LA-PV junction as compared with PAF (P < 0.001). Eighty-one percent of the PCs were located in the area between the left and right superior PVs. The incidence of PCs was similar between the PeAF and PAF patients (P = NS). PCs were more commonly found with APBs inducing AF (63.3%) than with those not inducing AF (35.2%, P = 0.01). The CV of the PC was slower for PeAF than PAF (P < 0.001). The CV in the LA during sinus rhythm was also slower for PeAF than PAF (P < 0.01).

CONCLUSION

PeAF was more frequently triggered by APBs from the LA side of the LA-PV junction than PAF and resulted in slower conduction than did PAF. These findings may help explain the higher potential for recurrence after electrical PV isolation in patients with PeAF.