wk4patho - Running head WK4PATHO 1 wk4patho April Matthews...

Running head: WK4PATHO 1
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April Matthews
Walden University

WK4PATHO 2
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Then, explain how hypertension or dyslipidemia can lead to the alteration you selected for
patients with the factor you identified.
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Myocardial Infarction
Myocardial infarction is when there is death of the myocardial tissue, often referred to as a “heart
attack”. This occurs when perfusion to the heart is occluded for greater than 20 minutes. When
the demands on the heart increase there is a need for increased oxygenation. When increased,
oxygen is needed healthy vessels will dilate to increase blood flow to the myocardium. If there is
“a narrowing of a major coronary artery by more than 50%, it decreases blood flow enough to
hamper cellular metabolism” (Huether & McCance, 2017, p. 613). Ischemia occurs if the oxygen
is not enough to meet the demands. The most common cause of ischemia is a blockage caused by
atherosclerotic plaques. They plaques can be stable or unstable. The unstable clots are prone to
rupture, resulting in platelet adhesion and thrombus. A few other causes of ischemia are;
coronary spasm, hypotension, dysrhythmia. “Some common causes for increased myocardial
demand are: tachycardia, exercise, hypertension, and valvular disease” (Huether & McCance,
2017, p. 613). Ischemia takes place when the myocardial cells have been occluded for 10
seconds, initiating an anaerobic process to start and lactic acid to accumulate. The heart can