Non-contrast myocardial T1 global and regional reference values at 3 Tesla cardiac magnetic resonance in aortic stenosis.

Background: T1 mapping using cardiac magnetic resonance (CMR) was recently proposed as a promising non-contrast imaging technique for the assessment of diffuse myocardial fibrosis (MF) in aortic stenosis (AS).

Aims: To provide reference values for native T1 mapping at 3 Tesla magnetic field strength in subjects with moderate or severe AS and in control subjects; to identify factors associated with the presence of diffuse MF in severe AS; to assess the regional distribution of diffuse MF; and to compare the level of diffuse MF in the different types of AS, stratified by flow and gradient patterns.

Methods: Retrospective study based on 160 consecutive patients with moderate (n=11) to severe (n=149) AS and 47 control subjects referred for CMR.

Active compression versus standard anterior-posterior defibrillation for external cardioversion of atrial fibrillation: A prospective randomized study.

Background: Electrical cardioversion is the first-line rhythm control therapy for symptomatic persistent atrial fibrillation (AF). Contemporary use of biphasic shock waveforms and anterior-posterior positioning of defibrillation electrodes have improved cardioversion efficacy; however, it remains unsuccessful in >10% of patients.

Objective: The purpose of this study was to assess the efficacy of applying active compression on defibrillation electrodes during AF cardioversion.