Targeting non-pulmonary vein triggers in persistent atrial fibrillation: results from a prospective, multicentre, observational registry.

AIMS: We evaluated the efficacy of an ablation strategy empirically targeting pulmonary veins (PVs) and posterior wall (PW) and the prevalence and clinical impact of extrapulmonary trigger inducibility and ablation in a large cohort of patients with persistent atrial fibrillation (PerAF). METHODS AND RESULTS: A total of 1803 PerAF patients were prospectively enrolled. All patients underwent pulmonary vein antrum isolation (PVAI) extended to the entire PW. A standardized protocol was performed to confirm persistent PVAI and elicit any triggers originating from non-PV sites. All non-PV triggers initiating sustained atrial tachyarrhythmias were ablated. Ablation of non-PV sites triggering non-sustained runs (<30 s) of atrial tachyarrhythmias or promoting frequent premature atrial complexes (≥10/min) was left to operator's discretion. Overall, 1319 (73.2%) patients had documented triggers from non-PV areas. After 17.4 ± 8.5 months of follow-up, the cumulative freedom from atrial tachyarrhythmias among patients without inducible non-PV triggers (n = 484) was 70.2%. Patients with ablation of induced non-PV triggers had a significantly higher arrhythmia control than those whose triggers were not ablated (67.9% vs. 39.4%, respectively; P < 0.001). After adjusting for clinically relevant variables, patients in whom non-PV triggers were documented but not ablated had an increased risk of arrhythmia relapse (hazard ratio: 2.39; 95% confidence interval: 2.01-2.83; P < 0.001). CONCLUSION: Pulmonary vein antrum isolation extended to the entire PW might provide acceptable long-term arrhythmia-free survival in PerAF patients without inducible non-PV triggers. In our population of PerAF patients, non-PV triggers could be elicited in ∼70% of PerAF patients and their elimination significantly improved outcomes.

Frequency of in-hospital adverse outcomes and cost utilization associated with cardiac resynchronization therapy defibrillator implantation in the United States.

BACKGROUND: The utilization of cardiac resynchronization therapy defibrillator (CRT-D) has increased significantly, since its initial approval for use in selected patients with heart failure. Limited data exist as for current trends in implant-related in-hospital complications and cost utilization. The aim of our study was to examine in-hospital complication rates associated with CRT-D and their trends over the last decade. METHODS AND RESULTS: Using the Nationwide Inpatient Sample, we estimated 378 248 CRT-D procedures from 2003 to 2012. We investigated common complications, including mechanical, cardiovascular, pericardial complications (hemopericardium, cardiac tamponade, or pericardiocentesis), pneumothorax, stroke, vascular complications (consisting of hemorrhage/hematoma, incidents requiring surgical repair, and accidental arterial puncture), and in-hospital deaths described with CRT-D, defining them by the validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code. Mechanical complications (5.9%) were the commonest, followed by cardiovascular (3.6%), respiratory failure (2.4%), and pneumothorax (1.5%). Age (≥65 years), female gender (OR, 95% CI; P value) (1.08, 1.03-1.13; 0.001), and the Charlson score ≥3 (1.52, 1.45-1.60; <0.001) were significantly associated with increased mortality/complications. CONCLUSIONS: The overall complication rate in patients undergoing CRT-D has been increasing in the last decade. Age (≥65), female sex, and the Charlson score ≥3 were associated with higher complications. In patients who underwent CRT-D implantation, postoperative complications were associated with significant increases in cost.

Temporal trends of in-hospital complications associated with catheter ablation of atrial fibrillation in the United States: An update from Nationwide Inpatient Sample database (2011-2014).

BACKGROUND: Catheter ablation is widely accepted intervention for atrial fibrillation (AF) refractory to antiarrhythmic drugs, but limited data are available regarding contemporary trends in major complications and in-hospital mortality due to the procedure. This study was aimed at exploring the temporal trends of in-hospital mortality, major complications, and impact of hospital volume on frequency of AF ablation-related outcomes. METHODS: The Nationwide Inpatient Sample database was utilized to identify the AF patients treated with catheter ablation. In-hospital death and common complications including vascular access complications, cardiac perforation and/or tamponade, pneumothorax, stroke, and transient ischemic attack, were identified using International Classification of Disease (ICD-9-CM) codes. RESULT: In-hospital mortality rate of 0.15% and overall complication rate of 5.46% were noted among AF ablation recipients (n = 50,969). Significant increase in complications during study period (relative increase 56.37%, P-trend < 0.001) was observed. Cardiac (2.65%), vascular (1.33%), and neurological (1.05%) complications were most common. On multivariate analysis (odds ratio [OR]; 95% confidence interval [95% CI]; P value), significant predictors of complications were female sex (OR = 1.40; CI = 1.17-1.68; P value < 0.001), high burden of comorbidity as indicated by Charlson Comorbidity Index ≥2 (OR = 2.84; CI = 2.29-3.52; P value < 0.001), and low hospital volume (< 50 procedures). CONCLUSION: Our study noted a decline in AF ablation-related hospitalizations and complications associated with the procedure. These findings largely reflect shifting trends of outpatient performance of the procedure and increasing safety profile due to improved institutional expertise and catheter techniques.

Painful left bundle branch block syndrome treated with his bundle pacing.

This is a case report of a patient with painful LBBB Syndrome that responded favorably to His Bundle Pacing. This syndrome is largely under recognized despite 50 reports in the literature over the last 60 years. Both diagnosis and treatment are not well defined and represent a major challenge in patients with this entity. Right ventricular pacing has been attempted with inconsistent efficacy outcomes. We report for the first-time complete resolution of chest pain with His bundle pacing. HBP provides a promising alternative pacing option that might provide symptom resolution to patients with a painful LBBB syndrome.

Long-term follow-up of patients with paroxysmal atrial fibrillation and severe left atrial scarring: comparison between pulmonary vein antrum isolation only or pulmonary vein isolation combined with either scar homogenization or trigger ablation.

AIMS: Left atrial (LA) scarring, a consequence of cardiac fibrosis is a powerful predictor of procedure-outcome in atrial fibrillation (AF) patients undergoing catheter ablation. We sought to compare the long-term outcome in patients with paroxysmal AF (PAF) and severe LA scarring identified by 3D mapping, undergoing pulmonary vein isolation (PVAI) only or PVAI and the entire scar areas (scar homogenization) or PVAI+ ablation of the non-PV triggers. METHODS AND RESULTS: Totally, 177 consecutive patients with PAF and severe LA scarring were included. Patients underwent PVAI only (n = 45, Group 1), PVAI+ scar homogenization (n = 66, Group 2) or PVAI+ ablation of non-PV triggers (n = 66, Group 3) based on operator's choice. Baseline characteristics were similar across the groups. After first procedure, all patients were followed-up for a minimum of 2 years. The success rate at the end of the follow-up was 18% (8 pts), 21% (14 pts), and 61% (40 pts) in Groups 1, 2, and 3, respectively. Cumulative probability of AF-free survival was significantly higher in Group 3 (overall log-rank P <0.01, pairwise comparison 1 vs. 3 and 2 vs. 3 P < 0.01). During repeat procedures, non-PV triggers were ablated in all. After average 1.5 procedures, the success rates were 28 (62%), 41 (62%), and 56 (85%) in Groups 1, 2, and 3, respectively (log-rank P< 0.001). CONCLUSIONS: In patients with PAF and severe LA scarring, PVAI+ ablation of non-PV triggers is associated with significantly better long-term outcome than PVAI alone or PVAI+ scar homogenization.

Trends in Use and Adverse Outcomes Associated with Transvenous Lead Removal in the United States.

BACKGROUND: Transvenous lead removal (TLR) has made significant progress with respect to innovation, efficacy, and safety. However, limited data exist regarding trends in use and adverse outcomes outside the centers of considerable experience for TLR. The aim of our study was to examine use patterns, frequency of adverse events, and influence of hospital volume on complications. METHODS AND RESULTS: Using the Nationwide Inpatient Sample, we identified 91 890 TLR procedures. We investigated common complications including pericardial complications (hemopericardium, cardiac tamponade, or pericardiocentesis), pneumothorax, stroke, vascular complications (consisting of hemorrhage/hematoma, incidents requiring surgical repair, and accidental arterial puncture), and in-hospital deaths described with TLR, defining them by the validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code. We specifically assessed in-hospital death (2.2%), hemorrhage requiring transfusion (2.6%), vascular complications (2.0%), pericardial complications (1.4%), open heart surgery (0.2%), and postoperative respiratory failure (2.4%). Independent predictors of complications were female sex and device infections. Hospital volume was not independently associated with higher complications. There was a significant rise in overall complication rates over the study period. CONCLUSIONS: The overall complication rate in patients undergoing TLR was higher than previously reported. Female sex and device infections are associated with higher complications. Hospital volume was not associated with higher complication rates. The number of adverse events in the literature likely underestimates the actual number of complications associated with TLR.

The Prevalence of Atrial Fibrillation and Conduction Abnormalities in Chagas' Disease: A Meta-Analysis.

BACKGROUND/OBJECTIVES: Chagas' disease (CD) has been associated with atrial fibrillation (AF) and electrocardiographic (ECG) conduction defects. However, prior studies have shown conflicting results. We performed a meta-analysis comparing the prevalence of AF and conduction abnormalities between CD and non-CD patients. METHODS: PubMed, EMBASE, Cochrane Central, and Latin American databases were searched for studies that directly compared the prevalence of AF and conduction defects in CD and non-CD patients. Odds ratios (OR) were computed using random-effects model due to anticipated heterogeneity. We further performed subanalyses limited to studies that included only patients with cardiomyopathy. RESULTS: A total of 17,238 patients from 30 studies were included, of whom 6,840 (40%) had a positive serology for CD. In the pooled data, AF was significantly more prevalent in the CD group (OR 1.62; 95%CI 1.21-2.15; P = 0.001). However, no significant difference was observed between groups when the analysis included only patients with cardiomyopathy (OR 1.21; 95%CI 0.97-1.50; P = 0.08) or heart failure (OR 1.09; 95%CI 0.81-1.47; P = 0.55). The combination of right bundle branch block (RBBB) and left anterior fascicular block (LAFB) had the highest OR for increased prevalence in patients with Chagas' cardiomyopathy compared to non-CD etiologies (OR 5.31; 95%CI 1.23-22.86; P = 0.03). CONCLUSIONS: Our meta-analysis suggests that the prevalence of AF in patients with Chagas' cardiomyopathy is not significantly different from non-CD cardiomyopathies. The pattern of RBBB and LAFB in patients with cardiomyopathy of unknown etiology and epidemiologic risk factors should raise the possibility of CD and prompt specific diagnostic testing.

Cryoballoon versus Radiofrequency Catheter Ablation in Atrial Fibrillation: A Meta-Analysis.

INTRODUCTION: Radiofrequency (RF) and cryoballoon (CB) catheter ablation are effective for pulmonary vein isolation (PVI) in atrial fibrillation (AF). This report presents an updated meta-analysis comparing the efficacy and safety of CB versus RF ablations in AF. METHODS: Databases and conference abstracts were systematically searched for studies that directly compared CB and RF PVI, and reported safety or efficacy outcomes in follow-up ≥12 months. Recurrent atrial tachyarrhythmias (AT) were defined as AF, atrial flutter, or atrial tachycardia. RESULTS: Twenty-two studies and 8,668 patients were included. Freedom from AT was not significantly different between CB and RF ablations in the pooled population (OR 1.12; 95%CI 0.97-1.29; P = 0.13) and in randomized trials (OR 1.0; 95%CI 0.65-1.56; P = 0.99). Second-generation CB (CB2; 78.1%) and contact-force (CF) sensing RF (78.2%) have improved procedure success rate as compared to first-generation technology (57.9% CB, 58.1% RF). As compared to CF-RF, CB2 demonstrated similar freedom from recurrent AT (OR 1.04; 95%CI 0.71-1.51; P = 0.84). The incidence of pericardial effusions (OR 0.44; 95%CI 0.28-0.69; P < 0.01), tamponade (OR 0.31; 95%CI 0.15-0.64; P < 0.01), and non-AF AT (OR 0.46; 95%CI 0.26-0.83; P < 0.01) were significantly lower with CB ablation, whereas transient phrenic nerve palsy was more incident after CB (OR 7.40; 95%CI 2.56-21.34; P < 0.01). CONCLUSION: There was comparable freedom from AT between CB and RF in patients with AF undergoing PVI. Additionally, freedom from AT was similar between CB2 and CF-RF. However, CB was associated with a lower incidence of pericardial effusions or tamponade, albeit with a higher rate of transient phrenic nerve palsies.

Contemporary trends of hospitalization for atrial fibrillation in the United States, 2000 through 2010: implications for healthcare planning.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. The associated morbidity and mortality make AF a major public health burden. Hospitalizations account for the majority of the economic cost burden associated with AF. The main objective of this study is to examine the trends of AF-related hospitalizations in the United States and to compare patient characteristics, outcomes, and comorbid diagnoses. METHODS AND RESULTS: With the use of the Nationwide Inpatient Sample from 2000 through 2010, we identified AF-related hospitalizations using International Classification of Diseases, 9th Revision, Clinical Modification code 427.31 as the principal discharge diagnosis. Overall AF hospitalizations increased by 23% from 2000 to 2010, particularly in patients ≥65 years of age. The most frequent coexisting conditions were hypertension (60.0%), diabetes mellitus (21.5%), and chronic pulmonary disease (20.0%). Overall in-hospital mortality was 1%. The mortality rate was highest in the group of patients ≥80 years of age (1.9%) and in the group of patients with concomitant heart failure (8.2%). In-hospital mortality rate decreased significantly from 1.2% in 2000 to 0.9% in 2010 (29.2% decrease; P<0.001). Although there was no significant change in mean length of stay, mean cost of AF hospitalization increased significantly from $6410 in 2001 to $8439 in 2010 (24.0% increase; P<0.001). CONCLUSIONS: Hospitalization rates for AF have increased exponentially among US adults from 2000 to 2010. The proportion of comorbid chronic diseases has also increased significantly. The last decade has witnessed an overall decline in hospital mortality; however, the hospitalization cost has significantly increased.

New-onset versus prior history of atrial fibrillation: Outcomes from the AFFIRM trial.

BACKGROUND: There are limited data on prognosis and outcomes of patients with new-onset atrial fibrillation (AF) compared with those with a prior history of AF. METHODS AND RESULTS: We conducted a comparison of these 2 groups in the AFFIRM trial. New-onset AF was the qualifying arrhythmia in 1,391 patients (34%). Compared with patients with prior history of AF, patients with new-onset AF were more likely to have a history of heart failure. There was no mortality difference between rate control (RaC) and rhythm control (RhC) among patients with new-onset AF (17% vs 20%, P = .152). In the univariate model, new-onset AF was associated with increased risk of mortality compared with history of prior AF (RaC unadjusted hazard ratio [HR] 1.36 [P = .010], RhC unadjusted HR 1.39 [P = .003]). However, after multivariate adjustments, new-onset AF did not carry an increased risk of mortality (RaC adjusted HR 1.14 [P = .370], RhC adjusted HR 1.16 [P = .248]). Subjects with new-onset AF randomized to the RhC arm were more likely to remain in normal sinus rhythm at follow-up (adjusted HR 0.79, P = .012) compared with patients with prior history of AF. CONCLUSIONS: In a multivariable analysis adjusting for confounders, new-onset AF was not associated with increased mortality compared with prior history of AF regardless of the treatment strategy. Patients with new-onset AF treated with the rhythm control strategy were more likely to remain in normal sinus rhythm on follow-up.

Management of Ventricular Arrhythmias in Patients with Mechanical Ventricular Support Devices.

The use of mechanical ventricular support devices in the management of patients with advanced heart failure continues to increase. These devices have been shown to prolong life as a destination therapy and to increase survival when used as a bridge to transplantation. However, they are associated with a high rate of complications, including bleeding, infection, device malfunction, and ventricular arrhythmias (VAs). The mechanical support provided by the device typically allows for VAs to be well tolerated in the acute setting, though there are numerous long-term complications related to VAs such as ventricular remodeling, right ventricular failure in patients with left ventricular assist devices, and possibly increased mortality. Controversy exists as to the appropriate role of implantable cardioverter defibrillators in these patients. This review will focus on the management options available for patients with mechanical ventricular support devices and VAs.

ICD discrimination of SVT versus VT with 1:1 V-A conduction: A review of the literature.

Inappropriate ICD shocks are associated with increased mortality. They also impair patients' quality of life, increase hospitalizations, and raise health-care costs. Nearly 80% of inappropriate ICD shocks are caused by supraventricular tachycardia. Here we report the case of a patient who received a single-lead dual-chamber sensing ICD for primary prevention of sudden cardiac death and experienced inappropriate ICD shocks. V-A time, electrogram morphology, and response to antitachycardia pacing suggested atrioventricular nodal reentry tachycardia, which was confirmed in an electrophysiology study. Inspired by this case, we performed a literature review to discuss mechanisms for discrimination of supraventricular tachycardia with 1:1 A:V relationship from ventricular tachycardia with 1:1 retrograde conduction.

In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: analysis of 93 801 procedures.

BACKGROUND: Atrial fibrillation ablation has made tremendous progress with respect to innovation, efficacy, and safety. However, limited data exist regarding the burden and trends in adverse outcomes arising from this procedure. The aim of our study was to examine the frequency of adverse events attributable to atrial fibrillation (AF) ablation and the influence of operator and hospital volume on outcomes. METHODS AND RESULTS: With the use of the Nationwide Inpatient Sample, we identified AF patients treated with catheter ablation. We investigated common complications including cardiac perforation and tamponade, pneumothorax, stroke, transient ischemic attack, vascular access complications (hemorrhage/hematoma, vascular complications requiring surgical repair, and accidental arterial puncture), and in-hospital death described with AF ablation, and we defined these complications by using validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. An estimated 93,801 AF ablations were performed from 2000 to 2010. The overall frequency of complications was 6.29% with combined cardiac complications (2.54%) being the most frequent. Cardiac complications were followed by vascular complications (1.53%), respiratory complications (1.3%), and neurological complications (1.02%). The in-hospital mortality was 0.46%. Annual operator (<25 procedures) and hospital volume (<50 procedures) were significantly associated with adverse outcomes. There was a small (nonsignificant) rise in overall complication rates. CONCLUSIONS: The overall complication rate was 6.29% in patients undergoing AF ablation. There was a significant association between operator and hospital volume and adverse outcomes. This suggests a need for future research into identifying the safety measures in AF ablations and instituting appropriate interventions to improve overall AF ablation outcomes.

Catheter ablation of atrial arrhythmias in cardiac sarcoidosis.

BACKGROUND: We previously reported on the incidence and clinical implications of supraventricular arrhythmia in patients with cardiac sarcoidosis (CS). The role of catheter ablation for the management of atrial arrhythmia (AA) in this patient population is unknown. METHODS AND RESULTS: One hundred consecutive patients with CS were monitored for the incidence of supraventricular arrhythmias. Those with persistent symptoms despite optimal medical therapy proceeded to catheter ablation. Following ablation, all patients were followed serially with Holter monitoring or device interrogation. Thirty-two (32%) patients had symptomatic supraventricular arrhythmias. Nine (28%) patients had symptomatic AA requiring catheter ablation for clinical indications. Mean age was 55 ± 11.6 years. Five (56%) patients had atrial fibrillation (AF), of whom 2 also had cavotricuspid isthmus ablation. Four patients had isolated atrial flutter: 2 patients with left atrial flutter, and 2 patients with cavotricuspid flutter. All other arrhythmias were ablated in the left atrium. Mean duration of follow-up was 1.8 ± 1.9 years. One patient with atypical atrial flutter, and one patient with AF have had recurrence; the remaining patients remain in sinus rhythm. CONCLUSIONS: Our study suggests that AA in CS is frequently left atrial in origin. Catheter ablation appears to be effective and safe for the maintenance of sinus rhythm in patients with CS.

The impact of transvenous lead extraction on tricuspid valve function.

BACKGROUND: Few data exist regarding the effect of transvenous lead extraction (TLE) on tricuspid valve function. The objective of this study was to examine the effect of TLE on the development of postprocedure tricuspid regurgitation (TR). OBJECTIVE: To assess the impact of TLE on tricuspid valve function. METHODS: A single center retrospective analysis of consecutive patients referred for TLE between June 2006 and November 2011. Patients were included only if they underwent transthoracic echocardiography (TTE) before and after lead extraction (N = 124). Patients were assigned a preprocedure and postprocedure TR score on a continuous scale from 0 to 6 (0 = none, 1 = trace, 2 = mild, 3 = mild/moderate, 4 = moderate, 5 = moderate/severe, and 6 = severe). A clinically significant increase in TR was defined as both (1) an increase in TR score of at least two points, and (2) a postprocedure TR score ≥4 (moderate). RESULTS: A total of 124 patients referred for TLE underwent a TTE both before (9 ±16 months) and after lead extraction (4 ± 8 months). A total of 200 leads (1.6 ± 0.8 per patient) were extracted. The mean change in TR score after lead extraction was +0.18 (95% confidence interval [CI] -0.03 to 0.39, P = 0.11). A clinically significant increase in TR occurred in 7/124 (5.6% [CI 2.3-11.3%]) patients. Age ≥75 (+0.45, [CI 0.07-0.84, P = 0.02]), removal of ≥2 leads (+0.40 [CI 0-0.81, P = 0.05]), and powered sheath-assisted extraction (+0.34 [CI 0.05-0.62, P = 0.02]) were significantly associated with an increase in TR score. CONCLUSION: TLE is rarely associated with the development of clinically significant TR. In our cohort, patient age ≥75 years, pacemaker as opposed to ICD, and removal of ≥2 leads predicted worsening TR.

Areas with complex fractionated atrial electrograms recorded after pulmonary vein isolation represent normal voltage and conduction velocity in sinus rhythm.

AIMS: Although complex fractionated atrial electrograms (CFAEs) are purported to represent critical sites for atrial fibrillation (AF) perpetuation, the mechanism and the significance of CFAE in the genesis of AF remain poorly understood. This study evaluated the relationship between CFAE and areas of abnormal atrial tissue defined by low-voltage electrograms (LVE) and signal average of the P-wave (SAPW). METHODS AND RESULTS: Complex fractionated atrial electrogram maps were obtained after pulmonary vein isolation in 15 patients with persistent AF. Patients were then cardioverted and voltage/activation maps were acquired in normal sinus rhythm (NSR). Total left atrium (LA), CFAE and LVE areas were measured as % of total LA area (mean ± SD). Conduction velocities of normal, LVE and CFAE areas were also measured during NSR. Patients underwent signal averaged ECG of the P-wave in NSR within 24 h of the procedure. Complex fractionated atrial electrograms areas accounted for 33 ± 24% of total LA. In NSR, only 12 ± 10% of LA area had LVE. There was no anatomic correlation between CFAE sites and LVE; the area of overlap between CFAE and LVE was only 1.6 ± 1.5%. Conduction velocity was faster in CFAE areas (2.3 ± 1.4 m/s) than in normal voltage areas (1.3 ± 0.3 m/s), and LVE areas (1.1 ± 0.7 m/s, P = 0.06). A positive correlation was only found between LVE areas and SAPW duration (r = 0.7, P = 0.04). CONCLUSION: Areas of CFAEs correspond to areas of normal atrial voltage and normal conduction velocity during NSR. Complex fractionated atrial electrogram probably represents the response of normal healthy atrial tissue to rapid pulmonary vein activation.

A proposal for new clinical concepts in the management of atrial fibrillation.

Atrial fibrillation (AF) represents a growing public health burden. It is a complex condition, involving a number of etiologic factors and arrhythmia mechanisms associated with atrial remodeling. Greater understanding of these mechanisms may improve therapy. Current AF classification schemes are limited by simplicity. A number of risk factors predict AF onset, and additional factors are being evaluated in registry studies. Doppler imaging and Holter monitoring in high-risk patients to predict the onset of AF and progression from paroxysmal to permanent AF are promising. There is a need for a novel multifactorial classification model encompassing AF duration, symptoms, markers of atrial remodeling, and a risk score for AF onset, persistence, progression, and complications to guide treatment and prognostication. Preventing AF onset with upstream therapy is of great interest, but current data are conflicting. More study is needed to optimize rhythm control with antiarrhythmic drugs and targeted ablation to specific patient populations at an earlier stage. There is little consensus on optimal rate control and no information relating to optimum rate control in specific populations. This article highlights new concepts in AF and directions for future research.

Acute electrical isolation is a necessary but insufficient endpoint for achieving durable PV isolation: the importance of closing the visual gap.

AIMS: Temporary, ablation-mediated effects such as oedema may cause reversible pulmonary vein (PV) isolation. To investigate this, point-by-point circumferential ablation was performed to achieve acute electrical PV isolation with an incomplete circumferential ablation line. Then, the impact of this intentional 'visual gap' (ViG) on the conduction properties of the ablation lesion set was assessed with adenosine and pacing manoeuvres. METHODS AND RESULTS: Twenty-eight patients undergoing ablation for paroxysmal (n= 20) or persistent atrial fibrillation (n= 8) were included. Pulmonary vein (PV) ablation was performed around ipsilateral vein pairs. Once acute isolation was achieved, ablation was halted and the presence and size of the ViG were calculated. The ViG electrophysiological properties were tested with pace capture along the ViG at 10 mA/2 ms, and assessment for dormant PV conduction with adenosine. Despite electrical isolation, a ViG was present in 75% (n= 42/56) of vein pairs (21 of 28 left PVs and 21 of 28 right PVs). There was no difference in the ViG size between the left and right PVs (22.1 ± 14.2 and 17.3 ± 11.3 mm, P > 0.05). Dormant PV connections were revealed by adenosine in more than a quarter (n= 12/42) of acutely isolated PV pairs, of which the majority were dependent on conduction through the ViG. CONCLUSIONS: Electrical PV isolation can usually be achieved without complete circumferential ablation. However, more than a quarter of these 'isolated' PVs exhibit dormant conduction-predominantly via the un-ablated 'ViGs' in the ablation lesion set. These findings support the hypothesis that reversible tissue injury contributes to PV isolation that may be acute but not necessarily durable.

A case of cardiac sarcoidosis with successful heart transplantation after COVID-19 infection.

Arrhythmogenic right ventricular cardiomyopathy and cardiac sarcoidosis can both present with ventricular tachycardia. We report a case of a patient whose histological diagnosis was not only confirmed by the transplanted heart but who also underwent successful transplantation after overcoming COVID-19. .

New anticoagulants for prevention of stroke in patients with atrial fibrillation.

Atrial fibrillation (AF) is the most common cardiac rhythm disorder and a major risk factor for ischemic stroke. Antithrombotic therapy using vitamin K antagonists (VKA) is currently prescribed for prevention of ischemic stroke in patients with AF. A narrow therapeutic range and frequent food and drug interactions underly the need for regular monitoring of anticoagulation intensity and impairs the utility and safety of VKA, stimulating a quest for alternative anticoagulant agents. Recently developed anticoagulants include the direct thrombin inhibitor, dabigatran, and the factor Xa inhibitors rivaroxaban, apixaban, edoxaban, to name those in the most advanced stages of clinical development. This review focuses on advances in the development of novel antithrombotic agents to provide practical information to clinicians on the use of these new drugs in patients with AF.