Changes in microRNA-1 expression and IK1 up-regulation in human atrial fibrillation.

Background: Atrial fibrillation (AF) is associated with increased inward-rectifier current activity that may stabilize atrial rotors maintaining the arrhythmia. Left atrial (LA) structures are important for AF maintenance, but previous studies have mostly evaluated changes in the right atrium. MicroRNA-1 (miR-1) reciprocally regulates inwardly rectifying potassium channel (Kir)2.

Comparison of hemodynamic performance of Medtronic Hall 21 mm versus St. Jude Medical 23 mm prostheses in pigs.

Background And Aim Of The Study: The ideal prosthesis for aortic valve replacement in the small annulus remains controversial, and has yet to be defined. In previous studies, the Medtronic Hall (MH) tilting disc valve showed superior hemodynamic performance in the hemodynamically optimum orientation compared to the St. Jude Medical (SJM) bileaflet valve, especially in smaller-sized valves.

Effect of mechanical aortic valve orientation on coronary artery flow: comparison of tilting disc versus bileaflet prostheses in pigs.

Objective: Orientation for optimal systolic performance of tilting disc and bileaflet aortic valves was defined in previous studies. The present study investigates the influence of valve orientation on coronary artery flow in an animal model.

Methods: A rotation device holding either a Medtronic Hall tilting disc (n = 4; Medtronic, Inc, Minneapolis, Minn), a St Jude Medical bileaflet (n = 4; St Jude Medical, Inc, St Paul, Minn), or a Medtronic Advantage bileaflet (n = 3) aortic valve was implanted.

Initial in vivo results of the new Medtronic Advantage(TM) bileaflet valve in aortic position and comparison to the SJM.

The present study investigated the Medtronic Advantage (MA) bileaflet valve in an animal model and compared the results to the St. Jude Medical (SJM) valve. Systolic performance and coronary artery flow in different orientations were studied.