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Atrial fibrillation (AF) is the most common arrhythmia and is associated with a significant morbidity and mortality. Invasive catheter ablation of AF has emerged as an effective therapy for patients with symptomatic AF. Atrial remodeling, particularly structural remodeling, is important not only for AF persistence but also for AF recurrence after ablation. Atrial dilation and fibrosis are two of the core processes involved in atrial structural remodeling. Increased automaticity and triggered activity occur in atrial structural remodeling, which may cause difficulty in maintaining sinus rhythm after ablation. Furthermore, an enlarged left atrium (LA) may increase the difficulty in achieving catheter stability and thereby require more energy to complete AF ablation. AF causes similar remodeling in both the left and right atria (RA), and myocardial changes in both atria influence AF recurrence. A non-invasive assessment of fibrotic structural remodeling helps predict the outcome of AF ablation. A variety of cardiac imaging modalities, such as two- or three-dimensional echocardiography or multi-detector row computed tomography, have been used to estimate the magnitude of atrial structural remodeling by measuring atrial volume or LA function. Furthermore, delayed enhanced cardiac magnetic resonance imaging has been used to detect not only atrial fibrosis but also the effect of the ablation point. Thus, atrial remodeling, particularly structural remodeling, plays an important role in AF recurrence. These non-invasive imaging modalities are significant tools for estimating atrial enlargement to improve patient selection for AF ablation at the point of paroxysmal AF, and for estimating atrial fibrosis to select the AF treatment including ablation strategy at the point of development to persistent or permanent AF. [ABSTRACT FROM AUTHOR]

Introduction: Remodeling and epicardial adipose tissue (EAT) in left atrium (LA) predict atrial fibrillation (AF) recurrence after pulmonary vein catheter ablation (CA), but those in right atrium (RA) have not been investigated for possible associations to AF recurrence. Hypothesis: We hypothesized that those in RA are also associated with post-CA AF recurrence. Methods: Using 128-slice multidetector computed tomography, atrium volume and EAT volume were measured 3-dimensionally before CA in 68 patients with initially proven AF (42 patients with paroxysmal AF and 26 patients with persistent AF, mean age, 65±11 years, 42.6% female) and 21 healthy volunteers with sinus rhythm (6±13 years and 52.3%). Results: In LA and RA, the largest atrial volume and EAT volume were the patients with persistent AF, followed in order by those with paroxysmal AF and the healthy volunteers (LA: volume (mL), 147, 104, and 63, EAT volume (mL), 9.5, 5.1, and 4.6, RA: volume, 105, 88, and 57, EAT volume, 11, 5.9, and 4.8 in each p<0.001). LA volume was correlated with RA volume (r=0.78), LA EAT volume (r=0.43), and RA EAT volume (r=0.42) (each p<0.001). Fifteen patients (22.1%) had AF recurrence for 2-year period after the CA. The recurrence was associated with large atrial volume (LA: hazard ratio (HR) of 1.02 [95% confidence interval (CI), 1 to 1.03, p=0.006] and RA: 1.02 [95% CI, 1 to 1.04, p=0.1]), and large atrial EAT volume (LA: 1.15 [95% CI, 1.02 to 1.31, p=0.024] and RA: 1.14 [95% CI, 1.06 to 1.24, p=0.001]). Large EAT volume in LA and RA predicted the recurrence (sensitivity of LA EAT volume≥6.8 mL: 73.3% in 11 of 15; specificity: 58.5% in 31 of 53, p=0.04, and sens. of RA EAT volume≥6.2 mL: 86.7% in 13 of 15; spec.: 50.9% in 27 of 53, p=0.02) similar to atrial volume (sens. of LA volume≥117 mL: 86.7% in 13 of 15 patients; spec.: 54.7% in 29 of 53, p=0.007, and sens. of RA volume≥88 mL: 80% in 12 of 15; spec.: 47.2% in 25 of 53, p=0.05). The combined estimate of those was incremental prognostic power of AF recurrence (LA volume≥117 mL and RA volume≥88 mL: 5.9 of HR [95% CI, 1.7 to 20.9, p=0.006], sens.: 80% in 12 of 15, spec.: 64.2% in 34 of 53, p=0.003, and LA EAT volume≥6.8 mL and RA EAT volume≥6.2 mL: 4.8 [95% CI, 1.7 to 13.7, p=0.003], sens.: 73.3% in 11 of 15, spec.: 66% in 35 of 53, p=0.009). After adjustment for potential confounding variables, the combination of those 4 factors was independent prognostic power with 4.8 of HR [95% CI, 1.7 to 13.7, p=0.003] (sens.: 60% in 9 of 15; spec.: 81.1% in 43 of 53, p=0.003). Conclusions: Remodeling and EAT volume are associated with post-CA AF recurrence in not only LA but also RA. [ABSTRACT FROM AUTHOR]

Atrial fibrillation (AF) is the most common arrhythmia and is associated with a significant morbidity and mortality. Invasive catheter ablation of AF has emerged as an effective therapy for patients with symptomatic AF. Atrial remodeling, particularly structural remodeling, is important not only for AF persistence but also for AF recurrence after ablation. Atrial dilation and fibrosis are two of the core processes involved in atrial structural remodeling. Increased automaticity and triggered activity occur in atrial structural remodeling, which may cause difficulty in maintaining sinus rhythm after ablation. Furthermore, an enlarged left atrium (LA) may increase the difficulty in achieving catheter stability and thereby require more energy to complete AF ablation. AF causes similar remodeling in both the left and right atria (RA), and myocardial changes in both atria influence AF recurrence. A non-invasive assessment of fibrotic structural remodeling helps predict the outcome of AF ablation. A varie ty of cardiac imaging modalities, such as two- or three-dimensional echocardiography or multi-detector row computed tomography, have been used to estimate the magnitude of atrial structural remodeling by measuring atrial volume or LA function. Furthermore, delayed enhanced cardiac magnetic resonance imaging has been used to detect not only atrial fibrosis but also the effect of the ablation point. Thus, atrial remodeling, particularly structural remodeling, plays an important role in AF recurrence. These non-invasive imaging modalities are significant tools for estimating atrial enlargement to improve patient selection for AF ablation at the point of paroxysmal AF, and for estimating atrial fibrosis to select the AF treatment including ablation strategy at the point of development to persistent or permanent AF.

Background: Erythropoietin (EPO) has been found to have anti-apoptotic and tissue protective effects on the myocardium. The aim of the present pilot study was to observe the safety and efficacy of EPO administration for patients with acute myocardial infarction (AMI)., Methods and Results: Patients admitted with AMI had all undergone successful percutaneous coronary intervention (PCI). Patients were randomly assigned to 2 groups (control and EPO groups), and given 12,000 IU EPO iv or saline after PCI. The primary endpoints were the difference between the acute phase and chronic phase (6 months after the attack) regarding left ventricular function as measured on electrocardiogram-gated single-photon emission computed tomography. Thirty-six patients (control 16, EPO 20) were eligible for analysis. Left ventricular ejection fraction (LVEF) significantly increased in the EPO group (from 51.0+/-19.6% to 58.5+/-15.0%, P=0.0238), but not in the control group. Further analysis was separately undertaken in patients with occlusion in the left anterior descending artery (LAD) and others (non-LAD). LVEF was <50% in most patients in the LAD subgroup, and LVEF significantly increased in the EPO group (37.5+/-13.0 to 52.7+/-15.8, P=0.0049), but not in the control group. EPO administration did not trigger any adverse clinical events., Conclusions: EPO administration is a promising treatment for AMI.