Valve morphology and timing of surgery in bicuspid aortic valve disease.

Background: The anatomy of bicuspid aortic valves (BAV) varies considerably and is broadly classified into two main types: two-sinus and fused BAV. Possible prognostic implications of these two main types remain unclear. This study aimed to assess potential associations between BAV morphology and the timing of surgery of the aortic valve or ascending aorta.

Measures of right ventricular function after transcatheter versus surgical aortic valve replacement.

Objectives: Describe changes in measures of right ventricular (RV) function in patients treated for aortic stenosis using open-chest surgery (SAVR) or transcatheter treatment (TAVR).

Methods: Patients in the Nordic Aortic Valve Intervention (NOTION) trial were randomized 1:1 to TAVR (n = 114) or SAVR (n = 106). Echocardiography was performed at baseline and 3 and 12 months post-procedure.

Two-Year Outcomes in Patients With Severe Aortic Valve Stenosis Randomized to Transcatheter Versus Surgical Aortic Valve Replacement: The All-Comers Nordic Aortic Valve Intervention Randomized Clinical Trial.

Background: The Nordic Aortic Valve Intervention (NOTION) trial was the first to randomize all-comers with severe native aortic valve stenosis to either transcatheter aortic valve replacement (TAVR) with the CoreValve self-expanding bioprosthesis or surgical aortic valve replacement (SAVR), including a lower-risk patient population than previous trials. This article reports 2-year clinical and echocardiographic outcomes from the NOTION trial.

Methods And Results: Two-hundred eighty patients from 3 centers in Denmark and Sweden were randomized to either TAVR (n=145) or SAVR (n=135) with follow-up planned for 5 years.

Significance of K(ATP) channels, L-type Ca²⁺ channels and CYP450-4A enzymes in oxygen sensing in mouse cremaster muscle arterioles in vivo.

Background: ATP-sensitive K⁺ channels (KATP channels), NO, prostaglandins, 20-HETE and L-type Ca²⁺ channels have all been suggested to be involved in oxygen sensing in skeletal muscle arterioles, but the role of the individual mechanisms remain controversial. We aimed to establish the importance of these mechanisms for oxygen sensing in arterioles in an in vivo model of metabolically active skeletal muscle. For this purpose we utilized the exteriorized cremaster muscle of anesthetized mice, in which the cremaster muscle was exposed to controlled perturbation of tissue PO₂.

Oxygen-dependent vasomotor responses are conducted upstream in the mouse cremaster microcirculation.

Background: A new method was evaluated where local changes in oxygen tension were induced in a tissue while being studied under a microscope in vivo. We tested whether hypoxic vasodilation and hyperoxic vasoconstriction in arterioles in striated muscle are being propagated upstream, and whether the endothelium and smooth muscle cell layers are necessary components in the signaling pathway.

Methods: The study was performed in mouse cremaster muscle superfused with Krebs buffer.

Oxygen sensing and conducted vasomotor responses in mouse cremaster arterioles in situ.

This study examines mechanisms by which changes in tissue oxygen tension elicit vasomotor responses and whether localized changes in oxygen tension initiates conducted vasomotor responses in mouse cremaster arterioles. Intravital microscopy was used to visualize the mouse cremaster microcirculation. The cremaster was superfused with Krebs' solution with different oxygen tensions, and a gas exchange chamber was used to induce localized changes in oxygen tension.