Contact-Force Guided Posterior Wall Isolation as an Adjunctive Ablation Strategy for Persistent Atrial Fibrillation.

BACKGROUND: The efficacy of posterior wall isolation (PWI) on top of pulmonary vein isolation (PVI) in patients affected by persistent atrial fibrillation (AF) is still controversial and little is known about the impact of contact-force (CF) technology. OBJECTIVE: In this retrospective study, we present our experience with PWI using CF sensing catheters and its efficacy and safety as an adjunctive ablation strategy on top of PVI for management of patients with persistent and longstanding persistent AF. METHODS: A total of 73 consecutive patients (20.5% female) affected by persistent atrial fibrillation (10.9% long-standing) underwent PWI as an adjunctive therapy to PVI using CF sensing catheters. Outcomes were reported as incidence of atrial arrhythmic recurrences (ARs) lasting >30 seconds at follow up and in addition, in patients provided with insertable cardiac monitors (ICM), as burden of AF or atrial tachycardias (AT) at relevant time points. RESULTS: PWI was successfully achieved in 65 (89.0%) patients. Two (2.7%) minor vascular procedural complications were observed. At 1 and 2-year follow-up, ARs free survival was observed in 80.5% and 64.1% of patients, respectively with 75.3% of patients off antiarrhythmic drugs at the last follow-up. Ten patients underwent repeat ablations during the follow-up. At multivariate analysis, early ARs within 3 months after procedure, were associated with a two-fold increased risk of late ARs at follow-up. Among patients provided with ICM, PWI on top of PVI was able to reduce the mean AT/AF burden of more than 50% compared with pre-ablation time, reporting very low levels (≤ 5%) over 2 years. CONCLUSIONS: In persistent atrial fibrillation, PWI on top of PVI using CF sensing catheters is safe and effective, providing great reduction of burden of ARs. Early ARs are associated with a greater risk of late recurrences.

Dobutamine stress echocardiography for assessing the role of dynamic intraventricular obstruction in left ventricular ballooning syndrome.

BACKGROUND: Dynamic intraventricular obstruction has been observed in patients with left ventricular ballooning syndrome (LVBS) and has been hypothesized as a possible mechanism of the syndrome. The aim of this study was to assess the prevalence and significance of dynamic intraventricular obstruction in patients with LVBS. METHODS AND RESULTS: Dobutamine stress echocardiography was carried out in 22 patients with LVBS (82% apical), all women, aged 68 +/- 9 years. At baseline 1 patient had a > 30 mmHg LV gradient; during stress a LV gradient > 30 mm Hg developed in 6/21 patients (28%) and was caused by systolic anterior motion of the mitral valve in the 3 patients with severe gradient (mean 116 +/- 29 mmHg), who developed mitral regurgitation and impaired apical wall motion and by obstruction at mid-ventricular level in the other 3 with a moderate gradient (mean 46 +/- 16 mmHg). Compared with patients without obstruction those with obstruction had a greater mean septal thickness (11.6 +/- .6 vs 9.8. +/- 3, p < .01), a higher prevalence of septal hypertrophy (71% vs 7%, p < .005) and a higher peak wall motion score index (1.62 +/- .4 vs 1.08 +/- .4, p < .01). CONCLUSION: Spontaneous or dobutamine-induced dynamic LV obstruction is documented in 32% of patients with LVBS, is correlated with the presence of septal hypertrophy and may play a role in the development of LVBS in this subset of patients. In those without septal hypertrophy a dynamic obstruction is rarely induced with dobutamine and is unlikely to be a major pathogenetic factor of the syndrome.

Catheter ablation of atrial fibrillation in patients with diabetes mellitus type 2: results from a randomized study comparing pulmonary vein isolation versus antiarrhythmic drug therapy.

INTRODUCTION: Atrial fibrillation (AF) and diabetes mellitus type 2 (DM2) often coexist; however, a small number of patients with DM2 undergoing catheter ablation (CA) of AF have been included in previous studies. The aim of this study was to evaluate safety and efficacy of ablation therapy in DM2 patients with drug refractory AF. METHODS AND RESULTS: From January 2005 to September 2006, 70 patients with a diagnosis of DM2 and paroxysmal (n = 29) or persistent (n = 41) AF were randomized to receive either pulmonary vein isolation or a new antiarrhythmic drug treatment (ADT) with a 1-year follow-up. The primary endpoint was the time to first AF recurrence. By Kaplan-Meier analysis, at the end of follow-up, 42.9% of patients in the ADT group and 80% of patients who received a single ablation procedure and were without medications were free of AF (P = 0.001). In the ablation group, a significant improvement in quality-of-life (QoL) scores as compared with ADT group was observed. Six patients in the ADT group (17.1%) developed significant adverse drug effects. Hospitalization rate during follow-up was higher in the ADT group (P = 0.01). The only complication attributable to ablation was one significant access-site hematoma. CONCLUSION: In patients with DM2, CA of AF provides significant clinical benefits over the ADT and appears to be a reasonable approach regarding feasibility, effectiveness, and low procedural risk.

Nonfluoroscopic mapping reduces radiation exposure in ablation of atrial fibrillation.

BACKGROUND: Radiofrequency catheter ablation (RFCA) of atrial fibrillation is an effective and definitive treatment. The methods used to guide RFCA have evolved over the years from a purely electrophysiological approach, in which anatomical lesions were guided solely by fluoroscopy and angiographic imaging of the pulmonary veins, to an approach guided by modern nonfluoroscopic electroanatomical mapping, integrated or not with computed tomography (CT). The aim of this study was, therefore, to compare radiation exposure of RFCA based on a fast three-dimensional nonfluoroscopic mapping system with 'traditional' mapping integrated with CT imaging. METHODS: Thirty consecutive patients with atrial fibrillation who underwent RFCA were treated with two different approaches: 3D-Fast-Anatomical-Mapping and One-Map tool (FAM-One Map group, 21 patients) vs. 3D-Fast-Anatomical-Mapping integrated with CT images (MERGE-CT group, nine patients). Fluoroscopy time and radiation doses (expressed in milliGray) were compared. RESULTS: No statistically significant difference was detectable between FAM-One Map group and MERGE-CT group considering RFCA success rates and fluoroscopy times. Radiation exposure was higher in the MERGE-CT group (965 ±â€Š138  mGy MERGE-CT group vs. 532 ±â€Š216  mGy FAM-One Map group, P < 0.001) because of supplemental radiation exposures due to CT imaging (470 ±â€Š126  mGy). CONCLUSION: A fast nonfluoroscopic electroanatomical mapping system may reduce radiation exposure in RFCA of atrial fibrillation, with preserved success rates.

Clinical impact of catheter ablation in patients with asymptomatic atrial fibrillation: the IRON-AF (Italian registry on NavX atrial fibrillation ablation procedures) study.

Whether and to what extent patients with asymptomatic atrial fibrillation (AF) would benefit from catheter ablation has not been investigated. This is the first multicenter prospective study reporting on the outcome of catheter ablation in patients with asymptomatic AF. Consecutive patients (n = 545) referred for AF ablation were prospectively enrolled in a multicenter Italian registry. Of these patients, 54 have asymptomatic AF and composed our patient population. At 24 month follow-up, catheter ablation in asymptomatic AF patients resulted to be as safe and effective as in patients with drug refractory symptomatic AF. Our study provides significant insights on the role of AF ablation in asymptomatic patients. Further studies in much larger cohorts are needed to validate our conclusions.

Role of dynamic intraventricular obstruction and protective effect of beta-blocking therapy in left ventricular apical ballooning syndrome: a case report.

This paper reports on a 58-year old woman with left ventricular apical ballooning syndrome (LVABS), who after interruption of beta-blocking therapy had a recurrence of symptoms and developed a severe dynamic left ventricular obstruction (LV-DYN-O) during sympathetic stimulation with dobutamine.

Left ventricular apical ballooning syndrome: prevalence, clinical characteristics and pathogenetic mechanisms in a European population.

BACKGROUND: Left ventricular apical ballooning syndrome (LVABS) is a cardiac syndrome mimicking acute myocardial infarction, whose prevalence in western populations and pathogenesis are not yet well defined. The aim of the study was to assess its prevalence, clinical characteristics and pathophysiological mechanisms in a European population of myocardial infarction patients. METHODS: Of a series of 1457 patients with acute myocardial infarction 18 fulfilled the diagnostic criteria for LVABS. To evaluate the pathogenetic mechanisms we studied coronary blood flow with TIMI flow grade and corrected TIMI frame count (CTFC) in all patients and performed provocative testing with ergonovine and dobutamine echocardiography in 14. RESULTS: All patients were women aged 72+/-9 years. A triggering event was identifiable in 39% of cases. LV ejection fraction in the acute phase was 46+/-5%. No deaths or major complications occurred during hospitalization. Response to ergonovine was negative in all 14 patients and dobutamine induced a dynamic LV obstruction in 4/14 (28%). Mean CTFC was abnormally prolonged in all 3 major coronary arteries and 16/18 patients (89%) had an abnormal CTFC in >/=1 coronary vessel. No cardiac deaths occurred during follow-up and 1 patient only had a recurrence. CONCLUSIONS: The prevalence of LVABS is 1.2% among all patients with acute myocardial infarction, but rises to 4.9% in women. Short- and long-term prognosis is good. Abnormal CTFC suggests the presence of a coronary microvascular dysfunction, while dynamic LV obstruction can contribute to the development of LVABS in a minority of patients.