Left atrial appendage electrical isolation for persistent atrial fibrillation.

Left atrial appendage (LAA) may be the source for initiation and maintenance of atrial fibrillation (AF). This report shows restoration of sinus rhythm in the atria during radiofrequency wide-area LAA electrical isolation, whereas AF persists in the LAA.

Myocardial ischaemia-reperfusion injury in haematopoietic cell-restricted beta1 integrin knockout mice.

Evidence indicates that the intercellular adhesion molecule-1 and its counter-receptor beta2 integrin are cardioprotective proteins during myocardial ischaemia-reperfusion, but no data are available concerning the role of blood cell beta1 integrins in this process. We studied the effects of temporary myocardial ischaemia and reperfusion in blood cell-restricted beta1 integrin knockout mice (beta1(-/-)). The left descending coronary artery in conditional beta1(-/-) integrin (beta1(-/-)), beta1 integrin +/+ (beta1(+/+)) and beta1 integrin -/- bone marrow chimeric (beta1(-/-) BM) mice was ligated for 30 min, followed by reperfusion of either 3 h or 3 weeks.

Asymmetric dimethyl L-arginine (ADMA) is a critical regulator of myocardial reperfusion injury.

Objective: Endothelial dysfunction by the loss of nitric oxide (NO) is a critical event during reperfusion of ischemic myocardium. Reduced NO availability signals important pathophysiological changes leading to myocardial reperfusion injury. We have recently shown that NO biosynthesis can be disturbed by the endogenous NO synthase (NOS) inhibitor ADMA and that these changes are mediated by an impairment of its metabolism by dimethylarginine dimethylaminohydrolase (DDAH).