Epicardial fat pad within the transverse sinus mimicking a left atrial appendage thrombus.

The presence of left atrial thrombus is a contraindication to cardioversion or catheter ablation in patients with atrial fibrillation, due to the increased risk of systemic thromboembolism. Management of this situation includes changes in the anticoagulation regimen and repeat imaging tests. Accurate diagnosis of left atrial appendage thrombus is therefore essential but can sometimes be challenging. Multiple imaging modalities may sometimes be required in the setting of anatomical variations of the left atrial appendage and surrounding structures. We present the case of a patient awaiting ablation for atypical atrial flutter, who underwent a transthoracic echocardiogram that showed an echodense, mobile structure within the vicinity of the left atrial appendage, suggesting a possible thrombus. A cardiac CT demonstrated the image to correlate with an epicardial fat pad within the transverse sinus.

Left atrial effective conducting size predicts atrial fibrillation vulnerability in persistent but not paroxysmal atrial fibrillation.

BACKGROUND: The multiple wavelets and functional re-entry hypotheses are mechanistic theories to explain atrial fibrillation (AF). If valid, a chamber's ability to support AF should depend upon the left atrial size, conduction velocity (CV), and refractoriness. Measurement of these parameters could provide a new therapeutic target for AF. We investigated the relationship between left atrial effective conducting size (LAECS ), a function of area, CV and refractoriness, and AF vulnerability in patients undergoing AF ablation. METHODS AND RESULTS: Activation mapping was performed in patients with paroxysmal (n = 21) and persistent AF (n = 18) undergoing pulmonary vein isolation. Parameters used for calculating LAECS were: (a) left atrial body area (A); (b) effective refractory period (ERP); and (c) total activation time (T). Global CV was estimated as √A/T . Effective atrial conducting size was calculated as LAECS=A/(CV×ERP) . Post ablation, AF inducibility testing was performed. The critical LAECS required for multiple wavelet termination was determined from computational modeling. LAECS was greater in patients with persistent vs paroxysmal AF (4.4 ± 2.0 cm vs 3.2 ± 1.4 cm; P = .049). AF was inducible in 14/39 patients. LAECS was greater in AF-inducible patients (4.4 ± 1.8 cm vs 3.3 ± 1.7 cm; P = .035, respectively). The difference in LAECS between inducible and noninducible patients was significant in patients with persistent (P = .0046) but not paroxysmal AF (P = .6359). Computational modeling confirmed that LAECS > 4 cm was required for continuation of AF. CONCLUSIONS: LAECS measured post ablation was associated with AF inducibility in patients with persistent, but not paroxysmal AF. These data support a role for this method in electrical substrate assessment in AF patients.

Super-response to cardiac resynchronization therapy may predict late phrenic nerve stimulation.

Aims: Changes in the anatomical relationship between left phrenic nerve and coronary veins may occur due to the reverse remodelling observed in super-responders to cardiac resynchronization therapy (CRT) and might be the underlying mechanism in patients developing late-onset phrenic nerve stimulation (PNS) without evidence of lead dislodgement (LD). In this study, we sought to evaluate the role of super-response (SR) to CRT as a potential predictor of late-onset PNS. Methods and results: Consecutive patients implanted with a left ventricular (LV) lead in a single centre were retrospectively analysed. Phrenic nerve stimulation was classified as 'early' when it occurred within 3 months of implantation and 'late' for occurrences thereafter. 'Late' PNS was considered related to LD (LD-PNS) when LV threshold differed by > 1 V or impedance >250 Ω from baseline values or in case of radiological displacement. Cases not meeting the former criteria were classified as 'non-LD-PNS'. Super-response was defined as a decrease ≥30% of the left ventricluar end-systolic volume at 1-year echocardiography. At 32 ± 7 months follow-up, PNS occurred in 20 of 139 patients. Late non-LD-PNS incidence was significantly higher in the SR group (8/61; 13.1%) when compared with the non-SR (1/78; 1.3%) (P = 0.010). Super-response remained the only predictor of non-LD-PNS at multivariate analysis (odds ratio: 11.62, 95% confidence interval 1.41-95.68, P = 0.023). Conclusion: Incidence of late non-LD-PNS is higher among SR to CRT, suggesting a potential role of the changes in the anatomical relationship between left phrenic nerve and coronary veins.

A score model to predict risk of events in patients with Brugada Syndrome.

AIMS: Risk stratification in Brugada Syndrome (BS) remains challenging. Arrhythmic events can occur life-long and studies with long follow-ups are sparse. The aim of our study was to investigate long-term prognosis and risk stratification of BS patients. METHODS AND RESULTS: A single centre consecutive cohort of 400 BS patients was included and analysed. Mean age was 41.1 years, 78 patients (19.5%) had a spontaneous type I electrocardiogram (ECG). Clinical presentation was aborted sudden cardiac death (SCD) in 20 patients (5.0%), syncope in 111 (27.8%) and asymptomatic in 269 (67.3%). Familial antecedents of SCD were found in 184 individuals (46.0%), in 31 (7.8%) occurred in first-degree relatives younger than 35 years. An implantable cardioverter defibrillator (ICD) was placed in 176 (44.0%). During a mean follow-up of 80.7 months, 34 arrhythmic events occurred (event rate: 1.4% year). Variables significantly associated to events were: presentation as aborted SCD (Hazard risk [HR] 20.0), syncope (HR 3.7), spontaneous type I (HR 2.7), male gender (HR 2.7), early SCD in first-degree relatives (HR 2.9), SND (HR 5.0), inducible VA (HR 4.7) and proband status (HR 2.1). A score including ECG pattern, early familial SCD antecedents, inducible electrophysiological study, presentation as syncope or as aborted SCD and SND had a predictive performance of 0.82. A score greater than 2 conferred a 5-year event probability of 9.2%. CONCLUSIONS: BS patients remain at risk many years after diagnosis. Early SCD in first-degree relatives and SND are risk factors for arrhythmic events. A simple risk score might help in the stratification and management of BS patients.

Phrenic paralysis during cardiac electronic device implantation: incidence, causes and clinical course.

AIMS: Phrenic paralysis is a known complication of central venous catheterization, but it is not listed as a complication related to cardiac implantable electronic device (CIED) implants. The aim of this study is to describe the incidence, causes, clinical picture, and management of phrenic paralysis occurring in this scenario. METHODS AND RESULTS: We retrospectively analysed data from our CIED implantation database and identified those patients who suffered phrenic paralysis during the implantation procedure. Four of 891 patients (subclavian puncture in 626) developed phrenic paralysis during pacemaker or defibrillator implant procedures. Severe respiratory failure needing ventilatory support occurred in two, being the phrenic paralysis transient in all of the cases. CONCLUSIONS: Transient phrenic paralysis may occur during CIED implantation probably related to the infiltration of local anaesthesia in the subclavian area. Mechanism, prevention, and management are discussed.

One-year follow-up after single procedure Cryoballoon ablation: a comparison between the first and second generation balloon.

BACKGROUND: With respect to the first generation Cryoballoon (CB), the second generation (Cryoballoon Advance [CB-A], Medtronic, Minneapolis, MN, USA) was designed with technical modifications resulting in a larger and more uniform zone of freezing on the balloon's surface aiming at procedural outcome improvement in the setting of atrial fibrillation (AF) ablation. However, a comparison between both technologies on a midterm follow-up is missing in today's literature. METHODS: A total of 100 patients (the last 50 patients with the first generation CB and the first 50 patients with the second generation CB-A upon its inception in our center) having undergone a single CB ablation for paroxysmal AF (PAF) and having completed a 12-month follow-up, were consecutively included in our study. Freedom from AF off-antiarrhythmic drugs (AADs) after a single procedure was 78% (39/50) in CB-A and 58% (29/50) in the CB group (P = 0.03) during the whole follow-up duration. Considering a blanking period of 3 months, freedom from AF off-AAD was achieved in 84% (42/50) in CB-A, while 66% (33/50) were free from recurrence in the CB group (P = 0.038). Right phrenic nerve palsy (PNP) occurred in 8 patients (16%) in CB-A group and in 4 patients (8%) in the CB group. CONCLUSION: Freedom from AF on 12 months follow-up was significantly higher in the CB-A group with respect to the first generation device. The most frequent complication observed was PNP.

Spontaneous and adenosine-induced pulmonary vein reconnection after cryoballoon ablation with the second-generation device.

INTRODUCTION: Longer observational time and adenosine challenge have proven to be able to detect pulmonary vein (PV) reconnections. The aim of this study was to assess incidence of spontaneous and adenosine-induced PV reconnection after ablation with second-generation cryoballoon (CB-Adv). METHODS AND RESULTS: Fifty consecutive patients (76% male, mean age 60.5 ± 11.9 years) having undergone PV isolation (PVI) using the CB-Adv were enrolled. After isolation, reconnections were evaluated using the Achieve catheter over 30 minutes observation and adenosine administration during isoproterenol infusion (adenosine challenge). Among 200 PVs, isolation was achieved in 190 (95%) during the first application. Lower nadir temperature and longer rewarming time were associated with successful PVI (P = 0.02 and 0.04). Spontaneous (4 veins) and adenosine-induced (4 veins) PV reconnections occurred in the 4% of initially isolated veins (8 veins) in 6 patients (12%). At receiver-operator curve analysis, nadir temperature <-51 °C and rewarming time >28 seconds identified absence of reconnections (sensitivity 100% and 87%, area under the curve 0.75 and 0.72). Patients with right-sided early branching frequently experienced reconnections (P < 0.01). After a mean follow-up of 7.0 ± 1.7 months, 86% of patients were free from atrial fibrillation. None of those with PV reconnections experienced recurrences. CONCLUSIONS: The incidence of spontaneous and adenosine-induced PV reconnection following ablation with the novel CB-Adv is very low occurring in 4% of initially isolated veins. Nadir temperature <-51 °C and rewarming time >28 seconds identified absence of acute reconnections, thus avoiding prolonged waiting time and adenosine challenge in such cases.

Assessment of pericardial adhesions by means of the EpiCO2 technique: Brighton Adhesion Classification.

BACKGROUND: Epicardial ablation complications are more frequent in patients with preexisting pericardial adhesions. As opposed to the dry puncture technique, the coronary vein exit and carbon dioxide (CO2) insufflation (EpiCO2) technique allows diagnosing pericardial adhesions before subxiphoid puncture. OBJECTIVE: This study aimed to evaluate the efficacy of the EpiCO2 technique in diagnosing pericardial adhesions prior to subxiphoid puncture. METHODS: Following coronary vein exit, contrast was injected in the pericardial space, and adhesions classified using our novel Brighton Adhesion Classification (BAC) into BAC-0 (no adhesions), BAC-1 (dispersed adhesions), and BAC-2 (dense adhesions extending to the entire assessed area). CO2 insufflation allowed subclassification of BAC-1 adhesions into BAC-1a (not preventing epicardial access or restricting catheter movement) and BAC-1b (either preventing epicardial access or significantly limiting catheter movement). RESULTS: Intentional coronary vein exit (right atrial appendage exit in 1 case) was achieved in all 235 consecutive epicardial ablation procedures undertaken at our center. A diagnosis of BAC-0 was made in 219 cases (93.2%), BAC-1a in 9 cases (3.8%), BAC-1b in 2 cases (0.9%), and BAC-2 in 5 cases (2.1%). This led to not attempting subxiphoid puncture in 6 cases (2.6%) and abandoning epicardial mapping because of limited catheter movement in 1 case (0.4%). Access-related complications occurred in 7 cases (3%) only in the BAC-0 group. CONCLUSION: The EpiCO2 technique allows assessment of the presence of pericardial adhesions prior to attempting subxiphoid puncture for epicardial access, which may lead to a reduction in the procedural complications within this subset of patients.

A New Era in Epicardial Access for the Ablation of Ventricular Arrhythmias: The Epi-Co2 Registry.

OBJECTIVES: This multicenter registry aimed to assess the reproducibility and safety of intentional coronary vein exit and carbon dioxide insufflation to facilitate subxiphoid epicardial access in the setting of ventricular tachycardia ablation. BACKGROUND: Epicardial ablation for ventricular tachycardia is not a widespread technique due to the significant potential complications associated with subxiphoid puncture. The first experience in 12 patients showed that intentional coronary vein exit and carbon dioxide insufflation was technically feasible. METHODS: A branch of the coronary sinus was cannulated by means of a diagnostic JR4 coronary catheter. Intentional perforation at the distal portion of that branch was performed with a high tip load 0.014-inch angioplasty wire. A microcatheter was advanced over the wire into the pericardial space. Carbon dioxide was then insufflated into the pericardial space, allowing direct visualization of the anterior pericardial space to facilitate subxiphoid puncture. RESULTS: Intentional coronary vein exit was attempted in 102 consecutive patients in 16 different centers and successfully completed in 101 patients. Significant pericardial adhesions were confirmed in 3 patients, preventing carbon dioxide insufflation and epicardial ablation. None of the punctures were complicated with inadvertent right ventricular puncture or damage to a coronary artery. Significant bleeding (>80 ml) due to coronary vein exit occurred in 5 patients, without hemodynamic compromise. None of the patients required surgery. CONCLUSIONS: Coronary vein exit and carbon dioxide insufflation can be safely and reproducibly achieved to facilitate subxiphoid pericardial access in the setting of ventricular tachycardia ablation.

Long-term prognosis of drug-induced Brugada syndrome.

BACKGROUND: Patients with drug-induced Brugada syndrome (BS) are considered at a lower risk than those with a spontaneous type I pattern. Nevertheless, they can present arrhythmic events. OBJECTIVE: The purpose of this study was to investigate their clinical characteristics, long-term prognosis and risk factors. METHODS: A consecutive cohort of 343 patients with drug-induced BS was included and compared with 78 patients with a spontaneous type I pattern. RESULTS: The mean age was 40.7 ± 18.3 years. Sudden cardiac death (SCD) was the clinical presentation in 13 (3.8%) and syncope in 86 (25.1%); 244 (71.1%) were asymptomatic. Patients with drug-induced BS were less frequently men (180 (52.5%) vs 63 (80.8%); P < .01), were more frequently asymptomatic (244 (71.1%) vs 44 (56.4%); P < .01), and had less ventricular arrhythmias (VAs) induced during electrophysiology study (41 (13.2%) vs 31 (42.4%); P < .01). An implantable cardioverter-defibrillator was implanted in 128 patients (37.3%). During a median follow-up of 62.5 months (interquartile range 28.9-115.6 months), 34 patients presented arrhythmic events. The event rate was 1.1% person-year (vs 2.3% person-year in patients with a spontaneous type I pattern; P < .01). Presentation as SCD and inducible VAs were independent risk factors significantly associated with arrhythmic events (adjusted hazard ratio 22.0 and 3.5). Drug-induced BS was related to a better prognosis only in asymptomatic individuals. CONCLUSION: Drug-induced BS has a good prognosis if asymptomatic; however, SCD is possible. Clinical presentation as SCD and inducible VAs during electrophysiology study are independent risk factors for arrhythmic events. In asymptomatic patients, proband status and inducible VAs can help to identify patients at higher risk, but further evidence is needed.

P-wave indices as predictors of atrial fibrillation recurrence after pulmonary vein isolation in normal left atrial size.

AIMS: Prolonged P-wave duration and dispersion are universally accepted noninvasive markers for atrial electrical remodeling. Our aim was to analyze P-wave indices as predictors of atrial fibrillation recurrence after pulmonary vein isolation in patients with normal left atrial size. METHODS: From January 2008 to December 2011, 426 patients with drug-resistant symptomatic paroxysmal atrial fibrillation underwent pulmonary vein isolation as an index procedure by conventional radiofrequency or cryoballoon ablation in our center. Patients with left atrial dilatation, poor-quality electrocardiograms, atrial pacemaker stimulation, and those undergoing repeat procedures were excluded. A total of 201 patients were analyzed during a mean follow-up of 22 ±â€Š16 months. RESULTS: Patients with prolonged P-wave duration had higher rates of atrial fibrillation recurrences compared with those without prolonged P-wave duration (49 vs. 14%; P < 0.001). Atrial fibrillation recurrence was significantly associated with prolonged P-wave duration (129 ±â€Š13 vs. 119 ±â€Š11 ms; P < 0.001) and P-wave dispersion (54 ±â€Š12 vs. 42 ±â€Š10 ms; P < 0.001) compared with those who remained in sinus rhythm. P-wave duration and dispersion were independently associated with atrial fibrillation recurrence (hazard ratio 1.045, 95% confidence interval 1.027-1.063, P < 0.001; and hazard ratio 1.049, 95% confidence interval 1.022-1.078, P < 0.001, respectively), after adjusting for left atrial size and age. CONCLUSION: Prolonged P-wave duration and dispersion were found to be independently associated with higher recurrence rates of atrial fibrillation after pulmonary vein isolation in patients with normal left atrial dimension. Therefore, a prolongation of P-wave indices may help to identify those patients in whom electrical remodeling has already occurred and a more extensive ablation may be indicated.

Clinical characterisation and long-term prognosis of women with Brugada syndrome.

OBJECTIVES: Brugada syndrome (BS) in women is considered an infrequent condition with a more favourable prognosis than in men. Nevertheless, arrhythmic events and sudden cardiac death (SCD) also occur in this population. Long-term follow-up data of this group are sparse. The purpose of the present study was to investigate the clinical characteristics and long-term prognosis of women with BS. METHODS: A consecutive cohort of 228 women presenting with spontaneous or drug-induced Brugada type I ECG at our institution were included and compared with 314 men with the same diagnosis. RESULTS: Mean age was 41.5±17.3 years. Clinical presentation was SCD in 6 (2.6%), syncope in 51 (22.4%) and the remaining 171 (75.0%) were asymptomatic. As compared with men, spontaneous type I ECG was less common (7.9% vs 23.2%, p<0.01) and less ventricular arrhythmias were induced during programmed electrical stimulation (5.5% vs 22.3%, p<0.01). An implantable cardioverter defibrillator (ICD) was implanted in 64 women (28.1%). During a mean follow-up of 73.2±56.2 months, seven patients developed arrhythmic events, constituting an event rate of 0.7% per year (as compared with 1.9% per year in men, p=0.02). Presentation as SCD or sinus node dysfunction (SND) was risk factor significantly associated with arrhythmic events (hazard risk (HR) 25.4 and 9.1). CONCLUSION: BS is common in women, representing 42% of patients in our database. Clinical presentation is less severe than men, with more asymptomatic status and less spontaneous type I ECG and prognosis is more favourable, with an event rate of 0.7% year. However, women with SCD or previous SND are at higher risk of arrhythmic events.

Regular atrial tachycardias following pulmonary vein isolation for paroxysmal atrial fibrillation: a retrospective comparison between the cryoballoon and conventional focal tip radiofrequency techniques.

PURPOSE: Occurrence of atrial tachycardias (ATs) following radiofrequency (RF) pulmonary vein (PV) isolation for the treatment of paroxysmal atrial fibrillation (PAF) is a frequent complication. Cryoballoon (CB) ablation might create more homogeneous and demarcated lesions than traditional point by point RF approach, hypothetically leading to a lower incidence of ATs. Our aim is to compare incidence and mechanism of regular ATs occurring after ablation of PAF by means of circumferential point by point RF vs CB ablation. METHODS: Two hundred eighty-six consecutive patients undergoing a first PV isolation procedure, as treatment for PAF, were included and followed up for 12 months. Point by point RF ablation was performed in 186 patients and CB ablation in the remaining 100. Among the last ones, first generation (CB-1) was used in 59 patients and second generation one (CB-2) in 41. RESULTS: Incidence of regular ATs was higher following RF PV isolation when compared with CB ablation (11.3 vs 3.0%, P = 0.028). When compared separately with RF ablation, both CB-1 and CB-2 presented lower incidences of ATs (5.1 and 0.0%) but differences only remained significant for the CB-2 (P = 0.027). CONCLUSION: Patients with PAF undergoing a first PV isolation procedure by means of CB ablation present a significantly lower incidence of ATs than those in which PV isolation is achieved by means of circumferential point by point RF ablation.

Asymptomatic Brugada Syndrome: Clinical Characterization and Long-Term Prognosis.

BACKGROUND: Among Brugada syndrome patients, asymptomatic individuals are considered to be at the lowest risk. Nevertheless, arrhythmic events and sudden cardiac death are not negligible. Literature focused on this specific group of patients is sparse. The purpose of this study is to investigate the clinical characteristics, management, and long-term prognosis of asymptomatic Brugada syndrome patients. METHODS AND RESULTS: Patients presenting with spontaneous or drug-induced Brugada type I ECG and no symptoms at our institution were considered eligible. A total of 363 consecutive patients (200 men, 55.1%; mean age, 40.9±17.2 years; 41 [11.3%] with spontaneous type I ECG) were included. Electrophysiological study was performed in 321 (88.4%) patients, and ventricular arrhythmias were induced in 32 (10%) patients. An implantable cardioverter defibrillator was implanted in 61 (16.8%) patients. After a mean follow-up time of 73.2±58.9 months, 9 arrhythmic events occurred, accounting for an annual incidence rate of 0.5%. Event-free survival was 99.0% at 1 year, 96.2% at 5 years, and 95.4% at 10 and 15 years. Univariate analysis identified as risk factors: electrophysiological study inducibility (hazard ratio, 11.4; P<0.01), spontaneous type I (hazard ratio, 4.0; P=0.04), and previous sinus node dysfunction (hazard ratio, 8.0; 95% confidence interval, 1.0-63.9; P=0.05). At the multivariate analysis, only inducibility remained significant (hazard ratio, 9.1; P<0.01). CONCLUSIONS: Arrhythmic events in asymptomatic Brugada syndrome patients are not insignificant. Ventricular arrhythmia inducibility, spontaneous type I ECG, and presence of sinus node dysfunction might be considered as risk factors and used to drive long-term management.