Lucia Garberoglio

Linear Cryoablation of the Left Atrium Versus Pulmonary Vein Cryoisolation in Patients With Permanent Atrial Fibrillation and Valvular Heart Disease. Correlation of Electroanatomic Mapping and Long-Term Clinical Results

Background—The aim of this study was to clarify the role of pulmonary vein isolation (PVI) alone versus left atrial linear lesions in the treatment of permanent atrial fibrillation (AF) in patients with left atrial dilatation and valvular disease. The primary end point was to assess the persistence of sinus rhythm (SR) off antiarrhythmic drugs (AADs) at 2-year follow-up and to correlate clinical outcome with surgical results validated with electroanatomic mapping (EAM). Methods and Results—A total of 105 patients with permanent AF undergoing valve surgery were assigned to 3 different groups: in groups “U” and “7,” left atrial linear cryoablation was performed, whereas in group “PV” patients, anatomic cryoisolation of pulmonary veins only was performed. In groups U and 7, SR was achieved in 57% of patients, whereas it was achieved in 20% of PV patients during 2-year follow-up. In the first 51 patients, the ablation schemes were validated with EAM. The EAM showed that the U lesion was never obtained: in 59% of these patients, a complete 7 lesion was achieved instead; in the 7 group, a complete 7 lesion was present in 65% of patients, whereas a complete PVI was obtained in 71% of patients. Considering patients in whom a complete 7 lesion was demonstrated with the EAM, SR without AADs was achieved in 86% of patients, whereas only 25% of patients with complete PVI were in SR without AADs. Conclusions—In patients with permanent AF, left atrial dilatation and valvular heart disease linear lesions in the posterior region of the left atrium are more effective than PVI alone. With cryoablation, the surgical intent is fulfilled in only approximately 65% of the cases. Knowing the real anatomic and electrophysiological effects of surgical ablation is necessary to correctly interpret the clinical outcome.

Limited posterior left atrial cryoablation in patients with chronic atrial fibrillation undergoing valvular heart surgery

OBJECTIVES We sought to evaluate whether a limited surgical cryoablation of the posterior region of the left atrium was safe and effective in the cure of atrial fibrillation (AF) in patients with associated valvular heart disease. BACKGROUND Extensive surgical ablation of AF is a complex and risky procedure. The posterior region of the left atrium seems to be important in the initiation and maintenance of AF. METHODS In 32 patients with chronic AF who underwent heart valve surgery, linear cryolesions connecting the four pulmonary veins and the posterior mitral annulus were performed. Eighteen patients with AF who underwent valvular surgery but refused cryoablation were considered as the control group. RESULTS Sinus rhythm (SR) was restored in 25 (78%) of 32 patients immediately after the operation. The cryoablation procedure required 20 +/- 4 min. There were no intraoperative and perioperative complications. During the hospital period, one patient died of septicemia. Thirty-one patients reached a minimum of nine months of follow-up. Two deaths occurred but were unrelated to the procedure. Twenty (69%) of 29 patients remained in SR with cryoablation alone, and 26 (90%) of 29 patients with cryoablation, drugs and radiofrequency ablation. Three (10%) of 29 patients remained in chronic AF. Right and left atrial contractility was evident in 24 (92%) of 26 patients in SR. In control group, two deaths occurred, and SR was present in only four (25%) of 16 patients. CONCLUSIONS Linear cryoablation with lesions connecting the four pulmonary veins and the mitral annulus is effective in restoration and maintenance of SR in patients with heart valve disease and chronic AF. Limited left atrial cryoablation may represent a valid alternative to the maze procedure, reducing myocardial ischemic time and risk of bleeding.

Different patterns of atrial activation in idiopathic atrial fibrillation: simultaneous multisite atrial mapping in patients with paroxysmal and chronic atrial fibrillation

OBJECTIVES We aimed to evaluate: 1) the behavior of electrical activity simultaneously in different atrial regions during atrial fibrillation (AF); 2) the difference of atrial activation between paroxysmal and chronic AF; 3) the atrial refractoriness dispersion; and 4) the correlation between the effective refractory periods (ERPs) and the FF intervals. BACKGROUND Little data exist on the electrophysiologic characteristics of the different atrial regions in patients with AF. A more detailed knowledge of the electrical activity during AF may provide further insights to improve treatment of AF. METHODS Right and left atria were extensively mapped in 30 patients with idiopathic AF (18 paroxysmal and 12 chronic). In different atrial locations, we analyzed 1) the FF interval duration; and 2) the grade of organization and, in case of organized electrical activity, the direction of atrial activation. Furthermore, in patients with paroxysmal AF, we determined the atrial ERP, evaluated the ERP dispersion and assessed the presence of a correlation between the ERPs and the FF intervals. RESULTS In patients with chronic AF, we observed a shortening of the FF intervals and a greater prevalence of disorganized activity in all the atrial sites examined. In patients with paroxysmal AF, a significant dispersion of refractoriness was observed. The right lateral wall showed longer FF intervals and more organized atrial activity and, unexpectedly, the shortest mean ERPs. In contrast, the septal area showed shorter FF intervals, greater disorganization and the longest mean ERPs. CONCLUSIONS Electrical activity during AF showed a significant spatial inhomogeneity, which was more evident in patients with paroxysmal AF. The mean FF intervals did not correlate with the mean ERPs.

Incidence of cerebral thromboembolic events during long-term follow-up in patients treated with transcatheter ablation for atrial fibrillation.

AIMS Net clinical benefit of long-term oral anticoagulation therapy (OAT) continuation after successful atrial fibrillation (AF) ablation is still controversial. To evaluate long-term thromboembolic (TE) and haemorrhagic events incidence according to OAT strategy used after AF transcatheter ablation. METHODS AND RESULTS Three months after AF ablation, OAT was discontinued in patients with CHADS2 ≤ 1 if no recurrences were documented, while OAT was maintained in patients with CHADS2 ≥ 2 regardless of AF recurrences. CHA2DS2VASc and HAS-BLED scores have been retrospectively evaluated. Seven hundred and sixty-six patients were followed for a median of 60.5 months. Six (6/267 = 2.2%) and five (5/499 = 1%) TE events occurred in the ON and the OFF-OAT patients, respectively (P = 0.145), all in concomitance with the AF recurrence. CHADS2 and CHA2DS2VASc ≥ 2 were associated with high TE incidence (P = 0.047 and P = 0.020). Among patients with a CHADS2 score of 0 or 1, a CHA2DS2VASc score ≥ 2 was predictive of TE events (P = 0.014). Overall, the incidence of the TE events in patients with CHA2DS2VASc ≥ 2 was 0.6 per 100 patient-years whereas seven haemorrhagic events occurred, all of them in the ON-OAT patients (7/267 = 2.6%). CONCLUSION Patients with AF undergoing transcatheter ablation have a lower incidence of TE events as compared with the general AF population, regardless of OAT maintenance. The unpredictable risk of AF recurrence, mandate the routine use of the CHADS2, CHA2DS2VASc, and HAS-BLED scores to guide clinical decision regarding OAT management in this peculiar setting of patients. The potential protective role of rhythm control strategy in the TE events needs to be confirmed by future large randomized trials.

Long-term progression from paroxysmal to permanent atrial fibrillation following transcatheter ablation in a large single-center experience

BACKGROUND The natural history of atrial fibrillation (AF) is characterized by gradual increase in duration and frequency of relapses until a definitive shift to permanent AF. Heart disease and comorbidities modulate AF progression. However, to date the influence of catheter ablation on AF evolution has rarely been investigated. OBJECTIVE The purpose of this study was to identify long-term predictors of AF progression in a large cohort of patients undergoing AF transcatheter ablation (AFTCA). METHODS A total of 889 patients (mean age 57 ± 11 years; 53.3% paroxysmal AF, 40.5% persistent AF, 6.2% long-standing AF) underwent AFTCA. All patients underwent pulmonary vein isolation, with linear lesions and complex fractionated atrial electrogram ablation reserved for patients with persistent/long-standing AF and/or confirmed structural heart disease. RESULTS After median follow-up of 64 months (range 41-84 years), AF progression despite AFTCA occurred in 57 cases (6.4%). However, AF progression was much more pronounced in patients with persistent (10%) or long-standing persistent AF (14.6%) than in those with paroxysmal AF (2.7%, P <.001). Furthermore, AF progression was more frequently reported in patients who presented with underlying comorbidities/cardiomyopathies (9.1%) than in those who presented with lone AF (29.9%, P <.001). At multivariate analysis, comorbidities/cardiomyopathies and baseline persistent/long-standing AF proved to be independent predictors of progression (odds ratio 11.3, 95% confidence interval 2.6-48.0, P <.001, and odds ratio 1.6, 95% confidence interval 1.2-2.1, P <.001, respectively). CONCLUSION The presence of comorbidities/cardiomyopathies and persistent/long-standing AF seem to predict AF progression in patients undergoing AFTCA. Performing AFTCA in the paroxysmal phase of the arrhythmia may reduce progression of AF to its permanent form.

Iatrogenic atrial septal defects following atrial fibrillation transcatheter ablation: a relevant entity?

AIMS The previous literature has suggested that the iatrogenic atrial septal defects (IASDs) may follow left atrial (LA) access by transseptal (TS) puncture, especially in the case of a single TS for more than one catheter. The aim of the present study is to describe the prevalence of patent foramen ovale (PFO) and IASDs in a cohort of atrial fibrillation (AF) patients undergoing redo catheter ablation (CA) procedures in a high-volume centre accessing LA by a standardized single TS puncture. METHODS AND RESULTS Patients (n = 197) who underwent at least one redo AFCA, between 2004 and 2012, were retrospectively enroled. Transoesophageal echocardiography was performed before each procedure during which LA was accessed via a PFO, if present, or by single TS for both the mapping and ablation catheters. At baseline, PFO was detected in 43 (21.8%) patients. Clinical and echocardiographic parameters recorded did not differ within patients presenting with or without PFO. Left atrium was accessed via PFO in 39 (90.7% of those with PFO) patients during the first procedure. New-onset IASD occurred in 11 (5.6%) patients following the first procedure and in 1 (2.2%) patient following the second procedure. The clinical and echocardiographic parameters did not differ within the patients irrespective of whether IASD was reported or not. No TS-related complications occurred. CONCLUSION In the present cohort, LA access by PFO or single TS for both the mapping and ablation catheters lead to a small risk of asymptomatic IASD, not increased by redo procedures, confirming that it represents a safe approach. No clinical and/or echocardiographic parameters seemed to predict IASD occurrence.

Left atrial appendage thrombi relate to easily accessible clinical parameters in patients undergoing atrial fibrillation transcatheter ablation: A multicenter study

BACKGROUND Transesophageal echocardiography (TEE) is routinely performed before atrial fibrillation (AF) transcatheter ablation to exclude the presence of left atrial (LA) or LA appendage (LAA) thrombi. The aim of the study is to evaluate if easily accessible clinical parameters may relate to the presence of LA or LAA thrombi to identify patients who could potentially avoid TEE. METHODS AND RESULTS Between January 2012 and September 2014, data from 1539 consecutive patients undergoing TEE, as a work-up before AF transcatheter ablation, in six large volume centers were collected. Baseline clinical features, CHA2DS2-VASc score, transthoracic echocardiography and presence of thrombi at TEE were recorded. Exclusion criteria were valvular, hypertrophic or dilated cardiomyopathy, previous heart surgery or an ejection fraction ≤35%. Mean age was 59.6±10.4years, 1215 (78.9%) were males; 951 (62.9%) presented in sinus rhythm (SR) on admission, 324 (21.1%) had undergone at least one previous ablation and 900 (58.5%) had CHA2DS2-VASc score 0-1. Thrombi were encountered in 12 patients (0.8%). SR at TEE independently related to the absence of thrombi (OR 5.15, 95% CI 1.38-19.02, p=0.015); in addition to this, no patient with a CHA2DS2-VASc score 0-1 and SR on admission presented thrombi at TEE (specificity 100%, p=0.011). CONCLUSION In a selected population of patients referred for AF ablation, LA/LAA thrombi prevalence is low. No patients in SR with CHA2DS2-VASc score 0-1 presented LAA thrombi at TEE, identifying a significant subset of patients who could potentially safely be spared from pre-procedural TEE.

Phenotypic expression of ARVC: How 12 lead ECG can predict left or right ventricle involvement. A familiar case series and a review of literature

AIMS Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart-muscle disease primarily affecting the right ventricle (RV) and potentially causing sudden death in young people. The natural history of the disease is firstly characterized by a concealed form progressing over a biventricular involvement. Three different cases coming from the same family are presented together with a review of the literature. METHODS AND RESULTS Multi-parameter analysis including imaging and electrocardiographic analysis is presented since the first medical referral with follow-up ranging from 11 to 38years. Case 1 presented a typical RV involvement in agreement with the ECG pattern. Case 2 presented a prevalent left ventricular involvement leading from the beginning to a pattern of dilated cardiomyopathy in agreement with his ECG evolution over the years. On the other side, Case 3 came to observation with a typical RV involvement (similar to Case 1) but with ECG evolution of typical left ventricle involvement (similar to Case 2). The genetic analysis showed a mutation in desmoglein-2 (DSG2) gene: p. Arg49His. Comparison between size and localization of ventricular dyskinesia at cardiovascular imaging and the surface 12 lead electrocardiography are proposed. CONCLUSIONS ARVC may lead to an extreme phenotypic variability in clinical manifestations even within patients coming from the same family in which ARVC is caused by the same genetic mutation. ECG progression over time reflects disease evolution and in particular cases may anticipate wall motion abnormalities by years.

Ablation of Atrial Fibrillation: How Should Patients Be Selected?

Atrial fibrillation is the most frequent supraventricular arrhythmia, and recently it has become clear that it is not a completely benign arrhythmia, since complications such as thromboembolism or ventricular impairment may sometimes occur. Even in absence of associated cardiac disease, when the incidence of these complications is relatively low, the presence of atrial fibrillation generally causes a worsening of quality of life, due to the irregularity of the rhythm or the high ventricular rate, and therefore generally requires life-long therapy.

Physiology of AV Junction: What Have We Learnt from Radiofrequency Ablation?

The atrioventricular (AV) junction is a rather complex structure involved in the genesis of the atrioventricular junctional reentrant tachycardia (AVJRT), which is the most frequent supraventricular arrhythmia. The advent of radiofrequency (RF) catheter ablation, that has been developed in the recent years, has provided a new therapeutic tool for the radical cure of this arrhythmia. In the meantime the more precise and extensive mapping of the septal region has provided new insight in the physiology and anatomy of the AV junction. This has led to questioning of some previously accepted concepts on its electrophysiology, and rekindled the interest of anatomists and experimental and clinical electrophysiologists, particularly in relation to the mechanism of reentry in humans.