Feasibility and safety of left bundle branch area pacing in cardiac amyloidosis. A single center experience.

BACKGROUND: Conventional right ventricle (RV) pacemaker stimulation has been associated with worse clinical outcomes in patients with cardiac amyloidosis (CA). Left bundle branch area pacing (LABPP) has been suggested as a promising alternative. We sought to assess the safety, feasibility, and outcomes of LABPP in patients with CA. METHODS: We retrospectively analyzed echocardiography and pacing parameters and clinical outcomes in 23 consecutive patients with CA and LBBAP implanted from June 2020 to October 2022. RESULTS: LBBAP was successfully performed in 22 over 23 patients (19 male, 78.6 ± 11.7 years, 20 ATTR, mean LVEF 45.5 ± 16.2%). After the procedure, 9 patients showed Qr pattern and 11 a qR pattern in V1 on ECG. Average procedure time was 67 ± 28 min. After 7.7 ± 5.2 months follow-up, no procedure-related complications had occurred. Although, a significant reduction in QRS width (p = .001) was achieved, we did not observe significant changes in LVEF and Nt ProBNP at 6 months of follow-up. Pacing parameters were stable during follow-up: LBB capture threshold and R wave amplitude were 1.0 ±  0.5 V and 10.6 ± 6.0 mV versus 0.8 ±  0.1 V, p = .21 and 10.6 ± 5.1 mV (p = .985) at follow up. CONCLUSION: LBBAP is safe and feasible pacing technique for patients with CA. LBBAP is associated with significant narrowing of QRSd without worsening in LVEF and Nt-proBNP.

Efficacy and safety of Proglide use and early discharge after atrial fibrillation ablation compared to standard approach. PROFA trial.

BACKGROUND AND OBJECTIVES: The common practice after atrial fibrillation ablation is to admit patients for an overnight stay. The aim of this study was to compare a strategy of vascular suture mediated closure system utilization and early discharge (strategy A) compared to traditional closure and overnight hospitalization (strategy B) regarding feasibility, safety, quality of life and health care cost effectiveness. METHODS AND RESULTS: Hundred patients were randomized to compare both strategies. No clinical differences were reported except diabetes mellitus. Six patients (6%) had and emergency visit or were admitted in the first 30 days after procedure. Three occurred in strategy A versus three in strategy B (p = 1) (p < .005 for non-inferiority). Forty out of 50 patients (80%) were safely discharged in a time frame of 3 h and 42 patients (84%) were discharged in the same day of the procedure in strategy A. Time to discharge was shorter in strategy A compared to strategy B. (5.89 ± 7.47 h vs. 27.09 ± 2.29 p < .005). No differences were obtained in quality-of-life outcomes. Mean (95% CI) euros cost saving per patient in strategy A was 379.16 ± 93.55 p < .001. Ten acute complications (10% patients CI 95% 4.02%-15.98%) were reported during the trial. Seven (14% CI 95% 4.04%-23.96%) occurred in strategy A patients versus 3 (6% CI 95% 0.8%-12.8%) in strategy B. (p = .182) CONCLUSION: A strategy of vascular suture mediated closure system utilization and early discharge was feasible, reduced time to discharge, saved costs and was not associated with more complications or admissions/emergency visits in a 30-day time frame after procedure compared to a strategy of regular admission and discharge after overnight stay. There were no differences regarding quality-of-life parameters between both strategies.

Experience and insights from a prolonged electrocardiographic monitorization with a wearable system after an embolic stroke of unknown source.

BACKGROUND: Embolic cerebrovascular events that remain of unknown etiology after a thorough diagnostic evaluation, are known as Embolic Strokes of Undetermined Source (ESUS). Subclinical atrial fibrillation (AF) represents a significant underlying cause of ESUS. Our aims were to examine the overall diagnostic yield of a prolonged cardiac monitoring wearable system (PCMw) after an ESUS to detect AF and factors associated with it, including the time frame from the ESUS event to PCMw initiation. Additionally, to evaluate the frequency of unexpected arrhythmic events (UAE) and their prognostic implications. METHODS: We retrospectively analyzed 200 ECG recordings (3-leads, 30 days duration) by means of a PCMw in patients with an ESUS to detect AF lasting longer than 30 s, between 2017 and 2021. UAE were defined as arrhythmia events that were not correlated to the main reason of prolonged cardiac monitoring. RESULTS: AF was detected in 21 patients (10.5%). Patients with AF had more left atrial enlargement (OR = 4.22 [1.59-6.85]; p = .01) and atrial arrythmias in the initial 24-h Holter during hospitalization (OR = 5.73 [2.03-16.49]; p = .001). The detection of AF was significatively higher if the PCMw was worn within the first 30 days after the ESUS compared to beyond 30 days (17% vs. 10.3%; p = .002). Fifty three patients (26.5%) had UAE during PCMw. In six of them these findings led to targeted treatment. CONCLUSION: PCMw represents a feasible non-invasive device that could reliably detect subclinical AF episodes after an ESUS. Diagnostic yield was significatively higher when used within the first 30 days after the event, especially in selected patients. UAE were common, but did not impact prognosis.

Estimation of the QTc interval in the presence of right bundle branch block: A comparative study using validated formulae for left bundle branch block.

BACKGROUND: Adequate measurement of the QT interval is of clinical importance in order to identify patients at higher risk for ventricular arrhythmias. Previous studies have described different methods to estimate baseline QT in patients with left bundle branch block (LBBB). However, the evidence regarding the assessment of the QT in patients with right bundle branch block (RBBB) is scarce. AIM: To analyze the feasibility and reliability of the different formulae described for LBBB in the estimation of the baseline QT in the presence of RBBB. METHODS: We performed an observational study including patients who underwent electrophysiology study and/or ablation. Two types of RBBB were considered: 1) pacing-induced and 2) transient true RBBB. QRS, JT and QT intervals were measured during baseline and RBBB. Estimated QTc was calculated using LBBB formulae: Bogossian, Rautaharju, Tabatabaei, Tang-Rabkin, Yankelson, Wang. Linear correlation and intraclass correlation coefficients (ICC) were used to assess the reliability of these formulae for the estimation of baseline QTc. RESULTS: We finally included a total of 100 patients. Correlations between baseline and estimated QTc were strong (R > 0.7) for all the formulae except for Tabatabaei. Yankelson and Wang showed the highest reliability (ICC = 0.775 and 0.727, respectively). Yankelson appeared to be the most accurate formula, with a mean estimated QTc closest to baseline values. CONCLUSION: Previously described formulae for LBBB exhibited marked differences regarding reliability in the estimation of the QTc interval in the presence of RBBB. According to our results, Yankelson showed the most consistent and accurate agreement in this setting.

The Role of Anxiety in Patients With Persistent Atrial Fibrillation Undergoing Elective Cardioversion: An Observational Study.

OBJECTIVE: Anxiety is often present among patients with atrial fibrillation (AF). This condition has been associated with greater symptom severity and worse quality of life in these patients. However, the influence of anxiety on the risk of AF recurrence is not well known. We aimed to define the level of anxiety in patients with persistent AF undergoing elective cardioversion (EC) and determine whether there is an association between anxiety and the risk of early AF recurrence after EC. METHODS: Anxiety was measured before EC using the State-Trait Anxiety Inventory. Early AF recurrence was assessed with a control electrocardiogram at 30-day follow-up. RESULTS: We included 107 patients undergoing effective EC. Early AF recurrence was diagnosed in 40 patients (37.4%). Compared with those who remained in sinus rhythm, individuals with early AF recurrence had significantly higher levels of trait anxiety (23.1 [10.4] versus 17.9 [9.5]; p = .013) and larger left atrial volume index (45.8 [12.3] versus 37.9 [13.3] ml/m; p = .004). Both variables remained independently associated with early AF recurrence after multivariate analysis. A predictive model including trait anxiety score >20 and left atrial volume index >41 ml/m showed acceptable accuracy for the diagnosis of early AF recurrence (area under the curve = 0.733; 95% confidence interval = 0.634-0.832; p < .001). CONCLUSIONS: Our study shows that trait anxiety is an independent risk factor for early AF recurrence after EC. Further studies are warranted to assess the beneficial role of anxiety-reducing strategies on the outcomes of patients with AF.

Arrhythmia detection using an implantable loop recorder after a negative electrophysiology study in Brugada syndrome: Observations from a multicenter international registry.

BACKGROUND: Risk stratification in Brugada syndrome (BrS) remains controversial. In this respect, the role of the electrophysiology study (EPS) has been a subject of debate. In some centers, it is common practice to use an implantable loop recorder (ILR) after a negative EPS to help in risk stratification. However, the diagnostic value of this approach has never been specifically addressed. OBJECTIVE: The aim of this study was to describe the baseline characteristics and the main findings of a diagnostic workup strategy with an ILR after a negative EPS in BrS. METHODS: We conducted a retrospective international registry including patients with BrS and negative EPS (ie, noninducible ventricular tachycardia or ventricular fibrillation) before ILR monitoring. RESULTS: The study included 65 patients from 8 referral hospitals in The Netherlands, Spain, and the United Kingdom (mean age, 39 ± 16 years; 72% male). The main indication for ILR monitoring was unexplained syncope/presyncope (66.2%). During a median follow-up of 39.0 months (Q1 25.0-Q3 47.6 months), 18 patients (27.7%) experienced 21 arrhythmic events (AEs). None of the patients died during follow-up. Bradyarrhythmias were the most common finding (47.6%), followed by atrial tachyarrhythmias (38.1%). Only 3 patients presented with ventricular arrhythmias. AEs were considered incidental in 12 patients (66.7%). In 11 patients (61.1%), AEs led to specific changes in treatment. CONCLUSION: The use of ILR after a negative EPS in BrS is a safe strategy that reflected the high negative predictive value of EPS for ventricular arrhythmia in this syndrome. In addition, it allowed the detection of AEs in a significant proportion of patients, with therapeutic implications in most of them.

Right Bundle Branch Block Predicts Appropriate Implantable Cardioverter Defibrillator Therapies in Patients with Non-Ischemic Dilated Cardiomyopathy and a Prophylactic Implantable Cardioverter Defibrillator.

Background: The benefit of prophylactic implantable cardioverter defibrillators (ICDs) in patients with severe systolic dysfunction of non-ischemic origin is still unclear, and the identification of patients at risk for sudden cardiac death remains a major challenge. Aims/Methods: We retrospectively reviewed all consecutive patients with non-ischemic dilated cardiomyopathy (NICM) who underwent prophylactic ICD implantation between 2008 and 2020 in two tertiary centers. Our main goal was to identify the predictors of appropriate ICD therapies (anti-tachycardia pacing [ATP] and/or shocks) in this cohort of patients. Results: A total of 224 patients were included. After a median follow-up of 51 months, 61 patients (27.2%) required appropriate ICD therapies. Patients with appropriate ICD therapies were more frequently men (87% vs. 69%, p = 0.006), of younger age (59 years, (53-65) vs. 64 years, (57-70); p = 0.02), showed more right bundle branch blocks (RBBBs) (15% vs. 4%, p = 0.007) and less left bundle branch blocks (LBBBs) (26% vs. 47%, p = 0.005) in the ECG, and had higher left ventricular end-diastolic (100 mL/m2, (90-117) vs. 86, (71-110); p = 0.011) and systolic volumes (72 mL/m2, (59-87) vs. 61, (47-81), p = 0.05). In a multivariate competing-risks regression analysis, RBBB (HR 2.26, CI 95% 1.02-4.98, p = 0.043) was identified as an independent predictor of appropriate ICD therapies. Conclusion: RBBBs may help to identify patients with NICM at high risk of ventricular arrhythmias and requiring ICD intervention.

Time to -30°C as a predictor of acute success during cryoablation in patients with atrial fibrillation.

BACKGROUND: Freezing rate of second-generation cryoballoon (CB) is a biophysical parameter that could assist pulmonary vein isolation. The aim of this study is to assess freezing rate (time to reach -30°C ([TT-30C]) as an early predictor of acute pulmonary vein isolation using the CB. METHODS: Biophysical data from CB freeze applications within a multicenter, nation-wide CB ablation registry were gathered. Successful application (SA), was defined as achieving durable intraprocedural vein isolation. And SA with time to isolation under 60 s (SA-TTI<60) as achieving durable vein isolation in under 60 s. Logistic regressions were performed and predictive models were built for the data set. RESULTS: 12,488 CB applications from 1,733 atrial fibrillation (AF) ablation procedures were included within 27 centers from a Spanish CB AF ablation registry. SA was achieved in 6,349 of 9,178 (69.2%) total freeze applications, and SA-TTI<60 was obtained in 2,673 of 4,784 (55.9%) freezes where electrogram monitoring was present. TT-30C was shorter in the SA group (33.4 ± 9.2 vs 39.3 ± 12.1 s; p < 0.001) and SA-TTI<60 group (31.8 ± 7.6 vs. 38.5 ± 11.5 s; p < 0.001). Also, a 10 s increase in TT-30C was associated with a 41% reduction in the odds for an SA (odds ratio [OR] 0.59; 95% confidence interval [CI] 0.56-0.63) and a 57% reduction in the odds for achieving SA-TTI<60 (OR 0.43; 95% CI 0.39-0.49), when corrected for electrogram visualization, vein position, and application order. CONCLUSIONS: Time to reach -30°C is an early predictor of the quality of a CB application and can be used to guide the ablation procedure even in the absence of electrogram monitoring.

Repeat cryoablation as a redo procedure for atrial fibrillation ablation: Is it a good choice?

BACKGROUND: Ablation of atrial fibrillation (AF), both cryoablation ablation (CBA) and radiofrequency catheter ablation (RFCA), have demonstrated to be safe and effective. About 1 in 3 patients may face a redo due to recurrence and the best technique is unknown. The aim of this study is to assess the efficacy of CBA as a repeat procedure in patients with prior CBA or RFCA. METHODS: A nation-wide CBA registry (RECABA) was analyzed and patients were compared who had previously undergone CBA (Prior-CB) or RFCA (Prior-RF). The primary endpoint was AF recurrence at 12 months after a 3-month blanking period. A survival analysis was performed, univariate and multivariate Cox models were also built. RESULTS: Seventy-four patients were included. Thirty-three (44.6%) were in the Prior-CB group and 41 (55.4%) in the Prior-RF. There were more reconnected pulmonary veins in the Prior-RF than in Prior-CB group (40.4% vs.16.5%, p = 0.0001). The 12-month Kaplan-Meier estimate of freedom from AF recurrence after the blanking period was 61.0% (95% confidence interval [CI] 41.4-75.8%) in the Prior-CB, and 89.2% (95% CI 73.6-95.9%) in the Prior-RF group (p = 0.002). Multivariate Cox regression pointed Prior-CB as the sole independent predictor of AF recurrence, with an adjusted HR of 2.67 (95% CI 1.05-6.79). CONCLUSIONS: Repeat CBA shows higher rates of AF recurrences compared to CBA after a previous RFCA despite presenting less reconnected veins at the procedure. These data suggest that patients with AF recurrence after CBA may benefit from other ablation techniques after a recurrence. RECABA is registered at clinicaltrials.gov with the Unique Identifier NCT02785991.

Benefits of cardiac pacing in ICD recipients with hypertrophic cardiomyopathy.

PURPOSE: Implantable cardiac defibrillator (ICD) is the only definitive therapy for prevention of sudden cardiac death in hypertrophic cardiomyopathy (HCM). Conventional transvenous ICDs can provide cardiac pacing unlike new subcutaneous ICD, but the usefulness of cardiac pacing in HCM patients is not well defined. We sought to assess the usefulness of ICD pacing in HCM. METHODS: We retrospectively analyzed 93 HCM patients who had undergone ICD implantation at our center. Usefulness of pacing was defined as follows: 1) need of pacing due to bradycardia or AV conduction disturbances, 2) improvement of LV outflow tract obstruction by sequential AV pacing, 3) need for CRT pacing, or 4) successful antitachycardia pacing without a subsequent shock. Independent predictors of useful pacing were investigated by multivariable analysis. RESULTS: During a mean follow-up of 91.3 ± 5.5 months, 43 patients (46.2%) reached the composite endpoint. Independent predictors of pacing usefulness were older age (HR 1.36; 95%CI: 1.088-1.709; p=0.007) and NYHA functional class ≥ II (HR 2.15; 95%CI: 1.083-4.301; p=0.029). Twenty-eight (30.1%) patients had appropriate ICD interventions, triggered by a monomorphic ventricular tachycardia (MVT) in 22 of them (78.5%). In 17 individuals with MVT (77%), antitachycardia pacing successfully treated MVT. CONCLUSIONS: In our HCM series of patients with ICD, 46% of individuals benefitted from cardiac pacing. MVT were documented in nearly 80% of the patients with ventricular arrhythmias and antitachycardia pacing successfully treated them in 77% of cases.

An unexpected cause of sudden cardiac arrest in a young swimmer.

Sudden cardiac arrest (SCA) is an uncommon but devastating event among young adults. While inherited cardiomyopathies and channelopathies represent an important proportion of sudden deaths, coronary artery disease remains a significant contributor in this age group. ECG findings are essential to guide the first steps of diagnostic work-up of SCA, but sometimes can overlap between different etiologies. In this article we present a 16-year-old female who experienced SCA during vigorous swimming whose ECG was compatible with long QT syndrome. However, evaluation of the coronary anatomy provided the diagnosis of Kawasaki disease.

Right ventricular function and dyssynchrony in Brugada syndrome: Highlighting the importance of the mechanical substrate in the right ventricular outflow tract.

BACKGROUND: Current evidence suggests that Brugada syndrome (BrS), far from being a purely electrical condition, is associated with subtle mechanical abnormalities primarily affecting the right ventricle (RV). We aimed to characterize RV function in BrS and investigate the echocardiographic profile of patients with arrhythmic events, with a special focus on parameters of RV dyssynchrony using speckle-tracking echocardiography (STE). METHODS: An echocardiogram was performed in 71 BrS patients and 25 healthy controls. STE was performed to assess regional and global RV mechanics, including RV outflow tract shortening (RVOTS). RVOT contraction time was considered to calculate the modified RV mechanical dispersion (RVMDm). Arrhythmic events were prospectively evaluated in the BrS cohort. RESULTS: Compared to controls, BrS patients showed subtle contractile abnormalities, including impaired RV longitudinal strain, higher RV index of myocardial performance (RIMP) and lower RVOTS. BrS patients also exhibited a greater contraction delay between the lateral and the septal aspect of the RV. After a median follow-up of 7.3 year (IQR 5.2-10.8), 6 patients presented malignant arrhythmic events. RIMP >0.50, RVOTS <16.2% and RVMDm > 42 ms showed high sensitivity for the identification of BrS patients with arrhythmic events during follow-up. CONCLUSIONS: Subtle RV mechanical abnormalities were present in BrS patients. RIMP and RVOTS, a novel STE-derived parameter, were found to be sensitive markers of arrhythmic events. Adding the RVOT contraction time to the analysis of RVMD may help identify patients at higher risk, reflecting the importance of the RVOT mechanical substrate in the assessment of the arrhythmic risk in BrS.

Ivabradine for chronic heart rate control in persistent atrial fibrillation. Design of the BRAKE-AF project.

INTRODUCTION AND OBJECTIVES: Ivabradine is an inhibitor of the If channel, the main determinant of the pacemaker function of the sinus node. The drug has been approved for the treatment of angina and heart failure. There is some evidence of its role as an inhibitor of atrial-ventricular node (AVN) conduction. The aim of the BRAKE-AF project is to assess ivabradine use for rate control in atrial fibrillation (AF). METHODS: A multicenter, randomized, parallel, open-label, noninferiority phase III clinical trial will be conducted to compare ivabradine vs digoxin in 232 patients with uncontrolled permanent AF despite beta-blockers or calcium channel blockers. The primary efficacy endpoint is the reduction in daytime heart rate measured by 24-hour Holter monitoring at 3 months. This clinical trial will be supported by an electrophysiological study of the effect of ivabradine on the action potential of the human AVN. To do this, an experimental model will be used with Chinese hamster ovarium cells transfected with the DNA encoding the expression of the t channels involved in this action potential and recording of the ionic currents with patch clamp techniques. RESULTS: New data will be obtained on the effect of ivabradine on the human AVN and its safety and efficacy in patients with permanent AF. CONCLUSIONS: The results of the BRAKE-AF project might allow inclusion of ivabradine within the limited arsenal of drugs currently available for rate control in AF. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov. Identifier: NCT03718273.

Proposal for a Novel Score to Determine the Risk of Cardiac Implantable Electronic Device Infection.

INTRODUCTION AND OBJECTIVES: The use of cardiac implantable electronic devices (CIEDs) has expanded in recent years. Infection related to these devices constitutes one of the main complications and is associated with high morbidity, mortality, and financial cost. The aim of this study was to construct a predictive risk score of acquiring CIED infection. METHODS: We designed a retrospective, nested case-control study. Both cases and controls belonged to a cohort that included all patients who underwent a CIED-related procedure between January 2009 and December 2015. Cases were defined as patients with infection, and 3 infection-free controls were randomly selected from the cohort for each case included. RESULTS: During the study period, 2323 procedures were performed. A total of 33 CIED-related infections were identified. Ninety-nine patients were selected as controls. Independent risk factors were the Charlson index (OR, 1.33; 95%CI, 1.07-1.67), oral anticoagulation (OR, 3.51; 95%CI, 1.44-8.54), revision or replacement of a previous device (OR, 2.75; 95%CI, 1.12-6.71) and the presence of more than 2 leads (OR, 3.42; 95%CI, 1.25-9.37). A predictive risk score was generated and denominated CIED-AI (Charlson Index, more than 2 leads/Electrodes, Device revision/replacement, oral Anticoagulation, previous Infection). This score had an area under the receiver operating characteristic curve of 0.79 (95%CI, 0.71-0.88). CONCLUSIONS: The CIED-AI score may help to identify patients at higher risk of infection, who could be candidates for intensive preventive measures.

Prevalence of cardiac amyloidosis among elderly patients with systolic heart failure or conduction disorders.

Objective: Cardiac amyloid infiltration can lead to systolic heart failure (HF) or to conduction disorders (CD). Patients with transthyretin (ATTR) amyloidosis are particularly exposed. We sought to determine the prevalence of ATTR and AL among patients >60 years admitted with CD or unexplained systolic HF and increased wall thickness. Materials and Methods: We studied 143 patients (57% males, 79 ± 9 years) with HF (N = 28) or CD requiring pacemaker implantation (N = 115). In total, 139 (97%) patients (28 with HF and 111 with CD) underwent 99mTc-DPD scintigraphy to detect ATTR, and 105 (73%; 19 HF and 86 CD) underwent AL screening. Results: Five patients (4%; 95%CI:0-7%) exhibited wild-type ATTR (ATTRwt) amyloidosis, 2 (2%; 95%CI:0-4%) had CD and 3 (11%; 95%CI:0-23%) HF. No patient showed AL. The 2 ATTRwt patients with CD were previously asymptomatic, did not show classical ECG signs and exhibited mild LV hypertrophy with preserved LVEF. By contrast, all ATTRwt patients with HF had ECG and echocardiographic signs of amyloid. During a mean follow-up of 18 ± 11 months, 3(60%) patients with ATTRwt amyloidosis (1 CD and 2 HF) and 14(10.4%) without died. Conclusion: Prevalence of ATTRwt amyloidosis in patients with CD requiring pacemaker is low. Although, additional studies are needed, prevalence seems to be higher in elderly patients with systolic HF.

[Bayes' syndrome in cardiac surgery: prevalence of interatrial block in patients younger than 65 years undergoing cardiac surgery and association with postoperative atrial fibrillation]. / Síndrome de Bayés en cirugía cardiaca: prevalencia de bloqueo interauricular en menores de 65 años sometidos a cirugía cardiaca y su asociación con fibrilación auricular en el postoperatorio.

OBJECTIVE: Interatrial block (IAB) is a well-known entity that is associated with an increased risk of atrial fibrillation (AF). This association is called Bayes' syndrome. The aim of our study was to define the prevalence of IAB among patients younger than 65 years undergoing cardiac surgery and determine whether there is an association between the presence of interatrial conduction delay and postoperative atrial fibrillation (POAF). METHOD: A total of 207 patients were enrolled. Partial IAB was defined as P-wave>120ms. Advanced IAB was defined as P-wave>120ms+biphasic morphology in the inferior leads. Ocurrence of POAF was assessed and a comparative analysis was conducted between patients that did and did not develop AF. RESULTS: IAB prevalence was 78.3% (partial 66.2%, advanced 12.1%). POAF occurred in 28.5% of all patients, and was more frequent among patients with advanced IAB (44%) compared to 27.7% and 24.4% of POAF among patients with partial IAB and without IAB, respectively. Patients who developed POAF were significantly older, had significantly higher NTproBNP, higher prevalence of atrial enlargement and thyroid disease. After multivariate analysis, advanced IAB was found to be independently associated with POAF. CONCLUSIONS: IAB is a frequent finding among patients undergoing cardiac surgery. According to our results, advanced IAB is independently associated with POAF in younger patients (<65 years) undergoing cardiac surgery.

Treatment of atrial fibrillation in patients with enhanced sympathetic tone by pulmonary vein isolation or pulmonary vein isolation and renal artery denervation: clinical background and study design : The ASAF trial: ablation of sympathetic atrial fibrillation.

BACKGROUND: Hypertension is an important, modifiable risk factor for the development of atrial fibrillation (AF). Even after pulmonary vein isolation (PVI), 20-40% experience recurrent AF. Animal studies have shown that renal denervation (RDN) reduces AF inducibility. One clinical study with important limitations suggested that RDN additional to PVI could reduce recurrent AF. OBJECTIVE: The goal of this multicenter randomized controlled study is to investigate whether RDN added to PVI reduces AF recurrence. METHODS: The main end point is the time until first AF recurrence according to EHRA guidelines after a blanking period of 3 months. Assuming a 12-month accrual period and 12 months of follow-up, a power of 0.80, a two-sided alpha of 0.05 and an expected drop-out of 10% per group, 69 patients per group are required. We plan to randomize a total of 138 hypertensive patients with AF and signs of sympathetic overdrive in a 1:1 fashion. Patients should use at least two antihypertensive drugs. Sympathetic overdrive includes obesity, exercise-induced excessive blood pressure (BP) increase, significant white coat hypertension, hospital admission or fever induced AF, tachycardia induced AF and diabetes mellitus. The interventional group will undergo PVI + RDN and the control group will undergo PVI. RESULTS: Patients will have follow-up for 1 year, and continuous loop monitoring is advocated. CONCLUSION: This randomized, controlled study will elucidate if RDN on top of PVI reduces AF recurrence.

[Left atrial posterior wall and pulmonary vein refractory periods are associated with atrial fibrillation inducibility in a swine model]. / El período refractario de la aurícula izquierda posterior y de las venas pulmonares se relaciona con la inducibilidad de fibrilación auricular en cerdos.

INTRODUCTION AND OBJECTIVES: Ectopic activity originating inside the pulmonary veins has been associated with paroxysmal atrial fibrillation in some patients. However, the roles played by the pulmonary veins and the posterior wall of the left atrium in maintaining atrial fibrillation are not well understood. METHODS: Our aim was to determine whether there is a correlation between the refractory period of either the lateral wall of the right atrium, the lateral wall of the left atrium, the posterior wall of the left atrium, or the pulmonary veins, and the inducibility of atrial fibrillation in an experimental swine model. We assessed atrial fibrillation inducibility using programmed atrial stimulation before and after intravenous administration of a high dose of methacholine in 20 pigs. RESULTS: Atrial fibrillation was induced in 17 out of the 20 pigs. Univariate analysis showed that there were negative correlations between all refractory periods and atrial fibrillation inducibility. A short refractory period was associated with greater inducibility. In the multivariate analysis, only the refractory periods of the posterior wall of the left atrium and the pulmonary veins were associated with inducibility. We also investigated the relationship between the local atrial fibrillation cycle length and refractory period; the only significant correlation was with the refractory period of the lateral wall of the right atrium (Pearson correlation coefficient 0.97). CONCLUSIONS: In an experimental swine model, the inducibility of atrial fibrillation was found to be associated with the refractory periods of both the pulmonary veins and the posterior wall of the left atrium.