A trial fibrillation (AF) is the most common human arrhythmia and is associated with increased risk for ischemic stroke and cardiovascular mortality. The pulmonary veins (PV) are important trigger sites of paroxysmal AF, 1 and their electric isolation from the left atrium (LA) is associated with a high rate of freedom from AF in patients without comorbidities.2 In persistent AF, however, additional arrhythmogenic atrial sites are responsible for AF maintenance and pulmonary vein isolation (PVI) is much less successful with reported 5-year AF freedom rate of 20% after a single and 45% after multiple procedures.3,4 Additional ablation strategies have been developed to improve outcomes including linear lesions and ablation of complex-fractionated atrial electrograms (CFAE) in the left and right atrium (RA), both as a stand-alone approach 5 or in addition to PV isolation. 6 Albeit improving the rate of AF-free survival in some studies, these ablation strategies are inconsistent because of the variable definition and significance of CFAE and require prolonged radiofrequency delivery times. Moreover, the recent multicenter trial, Substrate and Trigger Ablation for Reduction of Atrial Fibrillation 2 (STAR AF 2), did not reveal significant differences in rate of arrhythmia freedom between PVI only versus PVI+CFAE ablation versus PVI+linear ablation: all the 3 strategies resulted in a 1-year arrhythmia freedom of about 50%. 8,9 Recent clinical and experimental studies have identified more specific electrograms in a discrete point or within a region suggestive of a localized reentry during ongoing AF and have been associated with higher ablation impact on AF. Original ArticleBackground-Complex-fractionated atrial electrograms and atrial fibrosis are associated with maintenance of persistent atrial fibrillation (AF). We hypothesized that pulmonary vein isolation (PVI) plus ablation of selective atrial low-voltage sites may be more successful than PVI only. Methods and Results-A total of 85 consecutive patients with persistent AF underwent high-density atrial voltage mapping, PVI, and ablation at low-voltage areas (LVA<0.5 mV in AF) associated with electric activity lasting >70% of AF cycle length on a single electrode (fractionated activity) or multiple electrodes around the circumferential mapping catheter (rotational activity) or discrete rapid local activity (group I). The procedural end point was AF termination. Arrhythmia freedom was compared with a control group (66 patients) undergoing PVI only (group II). PVI alone was performed in 23 of 85 (27%) patients of group I with low amount (<10% of left atrial surface area) of atrial low voltage. Selective atrial ablation in addition to PVI was performed in 62 patients with termination of AF in 45 (73%) after 11±9 minutes radiofrequency delivery. AF-termination sites colocalized within LVA in 80% and at border zones in 20%. Singleprocedural arrhythmia freedom at 13 months median follow-up was achieved in 59 of 85 (69%) patients in group I, which was significantly higher th...

The criteria for the grading of aortic stenosis are inconsistent in patients with normal systolic LV function. On the basis of AVA, a higher proportion of patients is classified as having severe aortic valve stenosis compared with mean pressure gradient and peak flow velocity. Discrepant grading in these patients may be partly due to reduced stroke volume.

Background— Retrospective studies have suggested that patients with a low transvalvular gradient in the presence of an aortic valve area <1.0 cm 2 and normal ejection fraction may represent a subgroup with an advanced stage of aortic valve disease, reduced stroke volume, and poor prognosis requiring early surgery. We therefore evaluated the outcome of patients with low-gradient “severe” stenosis (defined as aortic valve area <1.0 cm 2 and mean gradient ≤40 mm Hg) in the prospective Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study. Methods and Results— Outcome in patients with low-gradient “severe” aortic stenosis was compared with outcome in patients with moderate stenosis (aortic valve area 1.0 to 1.5 cm 2 ; mean gradient 25 to 40 mm Hg). The primary end point of aortic valve events included death from cardiovascular causes, aortic valve replacement, and heart failure due to aortic stenosis. Secondary end points were major cardiovascular events and cardiovascular death. In 1525 asymptomatic patients (mean age, 67±10 years; ejection fraction, ≥55%), baseline echocardiography revealed low-gradient severe stenosis in 435 patients (29%) and moderate stenosis in 184 (12%). Left ventricular mass was lower in patients with low-gradient severe stenosis than in those with moderate stenosis (182±64 versus 212±68 g; P <0.01). During 46 months of follow-up, aortic valve events occurred in 48.5% versus 44.6%, respectively ( P =0.37; major cardiovascular events, 50.9% versus 48.5%, P =0.58; cardiovascular death, 7.8% versus 4.9%, P =0.19). Low-gradient severe stenosis patients with reduced stroke volume index (≤35 mL/m 2 ; n=223) had aortic valve events comparable to those in patients with normal stroke volume index (46.2% versus 50.9%; P =0.53). Conclusions— Patients with low-gradient “severe” aortic stenosis and normal ejection fraction have an outcome similar to that in patients with moderate stenosis.