Decreased bioavailability of hydrogen sulfide links vascular endothelium and atrial remodeling in atrial fibrillation.

Oxidative stress drives the pathogenesis of atrial fibrillation (AF), the most common arrhythmia. In the cardiovascular system, cystathionine γ-lyase (CSE) serves as the primary enzyme producing hydrogen sulfide (H2S), a mammalian gasotransmitter that reduces oxidative stress. Using a case control study design in patients with and without AF and a mouse model of CSE knockout (CSE-KO), we evaluated the role of H2S in the etiology of AF. Patients with AF (n = 51) had significantly reduced plasma acid labile sulfide levels compared to patients without AF (n = 65). In addition, patients with persistent AF (n = 25) showed lower plasma free sulfide levels compared to patients with paroxysmal AF (n = 26). Consistent with an important role for H2S in AF, CSE-KO mice had decreased atrial sulfide levels, increased atrial superoxide levels, and enhanced propensity for induced persistent AF compared to wild type (WT) mice. Rescuing H2S signaling in CSE-KO mice by Diallyl trisulfide (DATS) supplementation or reconstitution with endothelial cell specific CSE over-expression significantly reduced atrial superoxide, increased sulfide levels, and lowered AF inducibility. Lastly, low H2S levels in CSE KO mice was associated with atrial electrical remodeling including longer effective refractory periods, slower conduction velocity, increased myocyte calcium sparks, and increased myocyte action potential duration that were reversed by DATS supplementation or endothelial CSE overexpression. Our findings demonstrate an important role of CSE and H2S bioavailability in regulating electrical remodeling and susceptibility to AF.

Venous Adventitial Cystic Disease: A Review of 45 Cases Treated Since 1963.

Purpose. To review and identify the most accurate ways of diagnosing and treating adventitial cystic disease (ACD) of the venous system. Methods. Cases of ACD were collected through three popular medical databases, including PubMed, Cochrane, OVID, and MEDLINE. After reviewing the literature, the sites of occurrence of 323 cases of adventitial cystic disease were documented, and all cases of arterial ACD were excluded. The clinical features, treatment, and subsequent course of 45 cases of venous ACD are included in this paper. Results. After reviewing all 45 cases of venous ACD , we have confirmed that the most common vessel affected is the common femoral vein, which reproduces the most common symptom of venous ACD: asymmetric lower extremity swelling worsening over time. Conclusion. Venous ACD most commonly affects the common femoral vein. When unilateral leg swelling occurs with or without a noticeable mass, ACD should be considered. It is best confirmed with CT venography and the treatment of choice is transluminal cyst evacuation and excision.