Reduced expression of mitochondrial electron transport chain proteins from hibernating hearts relative to ischemic preconditioned hearts in the second window of protection.

Although protection against necrosis has been observed in both hibernating (HIB) and ischemic preconditioned hearts in the second window of protection (SWOP), a comparison of the mitochondrial proteome between the two entities has not been previously performed. Anesthetized swine underwent instrumentation with a fixed constrictor around the LAD artery and were followed for 12 weeks (HIB; N=7). A second group of anesthetized swine underwent ischemic preconditioning by inflating a balloon within the LAD artery 10 times for 2 min, each separated by 2 min reperfusion and were sacrificed 24h later (SWOP; N=7).

Uncoupling protein-2 expression and effects on mitochondrial membrane potential and oxidant stress in heart tissue.

Myocardial uncoupling protein (UCP)-2 is increased with chronic peroxisome proliferator-activated receptor γ (PPARγ) stimulation, but the effect on membrane potential and superoxide is unclear. Wild-type (WT) and UCP-2 knockout (KO) mice were given a 3-week diet of control (C) or the PPARγ agonist pioglitazone (PIO; 50 μg/g-chow per day). In isolated mitochondria, UCP-2 content by Western blots, membrane potential (ΔΨm) by tetraphenylphosphonium (TPP), and relative superoxide levels by dihydroethidium (DHE) were measured.

Altered expression of mitochondrial electron transport chain proteins and improved myocardial energetic state during late ischemic preconditioning.

Altered expression of mitochondrial electron transport proteins has been shown in early preconditioned myocardial tissue. We wished to determine whether these alterations persist in the Second Window of Protection (SWOP) and if so, whether a favorable energetic state is facilitated during subsequent ischemia. Fourteen pigs underwent a SWOP protocol with ten 2-minute balloon inflations in the LAD artery, each separated by 2 minutes reperfusion.

Continued depression of maximal oxygen consumption and mitochondrial proteomic expression despite successful coronary artery bypass grafting in a swine model of hibernation.

Objective: Clinical studies indicate incomplete functional recovery of hibernating myocardium after coronary artery bypass grafting. We hypothesized that persistent contractile abnormalities after coronary artery bypass grafting are associated with decreased mitochondrial proteins involving electron transport chain that might limit maximal oxygen consumption.

Methods: Seven pigs with hibernating myocardium underwent off-pump revascularization with left internal thoracic artery to mid left anterior descending artery.

Mechanical circulatory support for bridge to decision: which device and when to decide.

Despite the many advances in the management of patients with acute heart failure, the outcome for patients with refractory acute cardiogenic shock remains disproportionately poor. Clearly, there is a definitive role for wider application of temporary circulatory support in such patients. Questions remain as to the ideal device, the optimal duration of temporary support, and the ideal timing to bridge these patients to a long-term device.