Hibernating myocardium Hibernating myocardium In cardiology, hibernating myocardium is a state when some segments of the myocardium exhibit abnormalities of contractile function. These abnormalities can be visualised with echocardiography, cardiac magnetic resonance imaging (CMR), nuclear medicine (PET) or ventriculography. Echocardiography: A wall motion abnormality at rest which improves during a low-dose dobutamine stress test is classified as "hibernating myocardium". Low dose dobutamine stimulates contractile function and thus helps to predict functional recovery after revascularization. Cardiac magnetic resonance: The most frequently used MR contrast agents based on Gd-chelates accumulate in the extracellular space which is increased in scarred myocardium. This leads to a
Effect of spaceflight on the human body of muscle fibre prominent in muscles also change. Slow twitch endurance fibres used to maintain posture are replaced by fast twitch rapidly contracting fibres that are insufficient for any heavy labour. Advances in research on exercise, hormone supplements and medication may help maintain muscle and body mass. Bone metabolism also changes. Normally, bone is laid down in the direction of mechanical stress. However, in a microgravity environment there is very little mechanical stress. This results in a loss of bone tissue approximately 1.5% per month especially from the lower vertebrae, hip and femur. Due to microgravity and the decreased load