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The primary function of perfusion is the efficient removal of cellular waste and nutrition supply during gas exchange. Perfusion occurs during heart contraction when the oxygenated blood is pumped into the arteries. The arteries deliver the blood to the capillary bed of the tissues, where the oxygen is removed by diffusion. [7]
This matching may be assessed in the lung as a whole, or in individual or in sub-groups of gas-exchanging units in the lung. On the other side Ventilation-perfusion mismatch is the term used when the ventilation and the perfusion of a gas exchanging unit are not matched. The actual values in the lung vary depending on the position within the lung.
Smoking most commonly leads to diseases affecting the heart and lungs and will commonly affect areas such as hands or feet. First signs of smoking-related health issues often show up as numbness in the extremities, with smoking being a major risk factor for heart attacks, chronic obstructive pulmonary disease (COPD), emphysema, and cancer, particularly lung cancer, cancers of the larynx and ...
Myocardial infarction; Other names: Acute myocardial infarction (AMI), heart attack: A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, causing catastrophic thrombus formation, totally occluding the artery and preventing blood flow downstream to the heart muscle.
In the heart, increased arterial stiffness, increased systolic blood pressure, and widened pulse pressures, all resulting from chronic hypertension, can cause significant damage. Coronary perfusion pressures are decreased by these factors, which also increase myocardial oxygen consumption, possibly leading to left ventricular hypertrophy. As ...
When the heart contracts during systole, the contraction compresses the coronary arteries, which prevents perfusion. Therefore, it is only when the heart relaxes, during diastole , that the coronary vessels open up and allow for perfusion; thus CPP is highest during diastole, unlike most other arteries, which experience higher perfusion ...
This can actually trigger a heart attack in people with cardiac structural abnormalities i.e. coronary bridge, missing coronary, and atherosclerosis. If the heart rate drops too low for too long, catecholamines are released to counteract any lowering of blood pressure.
Myocardial perfusion imaging or scanning (also referred to as MPI or MPS) is a nuclear medicine procedure that illustrates the function of the heart muscle . [ 1 ] It evaluates many heart conditions, such as coronary artery disease (CAD), [ 2 ] hypertrophic cardiomyopathy and heart wall motion abnormalities.