Pouched mitral isthmus is associated with incomplete linear block in atrial fibrillation patients with mechanical mitral valve replacement.

BACKGROUND: Previous studies have described the impact of mitral isthmus (MI) anatomy on the likelihood of achieving MI linear block in patients with native mitral valves (NMV) who underwent atrial fibrillation (AF) ablation. However, none have investigated that issue in AF patients with mechanical mitral valve replacements (MMVR). METHODS AND RESULTS: Twenty-nine consecutive patients who developed symptomatic persistent AF post-MMVR and referred for ablation were enrolled. Twenty-nine patients with NMV who underwent ablation of persistent AF during the same period were matched. With preprocedural cardiac computed tomographic imaging, MI anatomical features of all the participants were analyzed. Pouched MI was observed in 19 (65.5%) MMVR patients versus to 6 (20.7%) controls (P = 0.001). Bidirectional linear block across MI was achieved in 21 (72.4%) MMVR patients and 22 (75.9%) in the controls (P = 0.764). In the multivariable analysis, pouched MI was an independent predictor of incomplete MI block. CONCLUSIONS: Pouched MI accounts for the majority of AF patients with MMVR and may be associated with incomplete bidirectional linear block of MI.

Plasma galectin-3 predicts clinical outcomes after catheter ablation in persistent atrial fibrillation patients without structural heart disease.

AIMS: This study sought to explore the relationship between plasma galectin-3 (Gal-3) and persistent atrial fibrillation (PsAF), and investigate whether Gal-3 predicts clinical outcomes in patients with PsAF undergoing catheter ablation. METHODS: Fifty consecutive PsAF patients without coexisting structural heart disease undergoing first-time catheter ablation and 46 healthy controls were included. Blood samples were collected on admission for analysis of plasma Gal-3. Pre-ablation clinical and laboratory data were also recorded. Persistent atrial fibrillations patients were followed after ablation and AF recurrence was defined as episodes of AF or atrial tachycardia lasting >30 s after the blanking period. RESULTS: Plasma Gal-3 concentrations were higher in PsAF patients than in healthy controls (P < 0.001). In PsAF group, those with AF recurrence had higher plasma Gal-3 than did those without recurrence (P = 0.007). Both Gal-3 (hazard ratio 1.28, P = 0.006) and left atrial diameter (LAD) (hazard ratio 1.1, P = 0.025) were independent predictors of AF recurrence after ablation. Moreover, adding Gal-3 to LAD had an incremental predictive value for ablation outcomes (global χ(2) of LAD alone: 8.2; LAD and Gal-3 concentrations: 15.7; P = 0.006). CONCLUSION: Plasma Gal-3 concentrations are elevated in PsAF patients without structural heart disease and independently predict AF recurrence after ablation. Plasma Gal-3 concentration may be helpful in identifying appropriate candidates for AF ablation.

Pacing or ablation: which is better for paroxysmal atrial fibrillation-related tachycardia-bradycardia syndrome?

BACKGROUND: Symptomatic prolonged sinus pauses on termination of atrial fibrillation (AF) are an accepted indication for pacemaker implantation. We evaluated the outcome of AF ablation in patients with paroxysmal AF-related tachycardia-bradycardia syndrome and compared the efficacy of catheter ablation with permanent pacing plus antiarrhythmic drugs (AADs). METHODS AND RESULTS: Patients with prolonged symptomatic sinus pauses on termination of AF were retrospectively analyzed. Forty-three consecutive patients who underwent catheter ablation (ABL group) were compared to 57 patients who underwent permanent pacing plus AADs (PM group). All 43 patients in the ABL group fulfilled Class I indication for pacemaker implantation at baseline but they actually underwent AF ablation. Reevaluation after 20.1 ± 9.6 months of follow-up showed that 41 patients (95.3%) did no longer need a pacemaker (Class III indication). Total cardiac-related rehospitalization was not significantly different between the two groups (P = 0.921). Tachycardia-related hospitalization was significantly higher in the PM group than the ABL group (14.0% and 0%, P = 0.029). More patients in the PM group were on AADs (PM 40.4%, ABL 4.7%, P < 0.001) while sinus rhythm maintenance was remarkably higher in the ABL group at the end of follow-up (83.7% vs 21.1% in PM group, P < 0.001). CONCLUSIONS: In patients with paroxysmal AF-related tachycardia-bradycardia syndrome, AF ablation seems to be superior to a strategy of pacing plus AAD. Pacemaker implantation can be waived in the majority of patients after a successful ablation.

Spontaneous coronary artery dissection and pseudoaneurysm: a case report.

Spontaneous coronary artery dissection (SCAD) is a very rare but potentially fatal condition, which often causes acute myocardial infarction and sudden cardiac death. Spontaneous coronary artery dissection associated with pseudoaneurysm has been rarely reported mostly managed with coronary artery bypass grafting. We report a female patient with SCAD and pseudoaneurysm who was treated by successful percutaneous coronary intervention.

LncRNA SNHG12 alleviates hypertensive vascular endothelial injury through miR-25-3p/SIRT6 pathway.

The objective of this study was to find the role of LncRNA SNHG12 in the regulation of hypertensive vascular endothelial injury. LncRNA SNHG12 and miR-25-3p expression were detected by quantitative RT-PCR. Protein levels of Sirtuin 6 (SIRT6), endothelial cell (EC) senescence markers p16 and p21, and EC marker CD31 were measured by Western blot. The apoptosis of HUVECs was detected by flow cytometry. The binding between LncRNA SNHG12 and miR-25-3p was verified by dual luciferase reporter gene assay and RNA pull-down assay. As a result, LncRNA SNHG12 was down-regulated in aortic primary ECs isolated from Ang II-induced hypertensive mice and 1 kidney/deoxycorticosterone acetate/salt-induced hypertensive mice. In Ang II-treated HUVECs, the expression level of SNHG12 was reduced and the overexpression of SNHG12 inhibited EC senescence markers p16 and p21 expressions, the apoptosis of HUVECs, and caspase-3 activity. Further investigation confirmed that LncRNA SNHG12 bound to miR-25-3p, and negatively regulated miR-25-3p expression. MiR-25-3p directly targeted SIRT6 and negatively regulated SIRT6 expression. In addition, SNHG12 overexpression inhibited Ang II-induced HUVECs injury through regulating miR-25-3p. Finally, in vivo experiments showed LncRNA SNHG12 overexpression alleviated vascular endothelial injury in Ang II-induced hypertensive mice. In conclusion, LncRNA SNHG12 alleviates vascular endothelial injury induced by hypertension through miR-25-3p/SIRT6 pathway.

Catheter ablation of atrial fibrillation in patients with atrial septal defect: long-term follow-up results.

INTRODUCTION: Atrial fibrillation (AF) is commonly found in patients with structural heart disease (SHD), including atrial septal defect (ASD). The feasibility and safety of ablation for AF in patients with unrepaired ASD is seldom reported. OBJECTIVES: This study aims to evaluate and compare the long-term efficacy of AF ablation in patients with and without ASD. METHODS: From January 2008 to December 2012, 18 consecutive patients were identified with medically refractory AF and an unrepaired ASD under catheter ablation. For each ASD patient, four control subjects were matched from our database. RESULTS: There were no significant differences between groups in terms of age, sex, type of AF, LA diameter, LVIDD, and EF. The mean procedural and fluoroscopy times were not different between the groups (p = NS). After a median follow-up of 20 months, the patients in the ASD group had 44.4 % AF recurrence after a single procedure compared with 34.7 % in the control group (p = 0.11). The mean LA diameter in non-recurrent patients was smaller than in recurrent patients (p = 0.03). In univariate Cox proportional hazards analyses, the factor found to have a significant association with arrhythmia recurrences was left atrial diameter (hazard ratio 1.059, 95 % confidence interval 1.002 to 1.120, p = 0.03). CONCLUSIONS: These results indicate that in patients with AF and an ASD amenable to percutaneous closure, a staged approach with radiofrequency ablation of AF preceding closure is a rational strategy.