A “heart attack” is a myocardial infarction (MI). An MI results from occlusion of the vasculature that supplies cardiac muscle (myo = muscle cardial = relating to the heart infarction = region of dead “necrosed” tissue).
Essentially, the different coronary arteries supply different regions of the heart. For example, the left coronary artery supplies most of the left atrium and left ventricle. Thus, a total blockage in the left coronary artery would result in an infarct in the left atrium and left ventricle.
Cardiac arrest occurs when there is a disruption of the normal rhythmic contractions of the heart, resulting in loss of spontaneous circulation of blood throughout the body. In this case, the “pump” is broken, and so the vital organs are starved of oxygen and nutrients. Unfortunately, the survival rate for out of hospital cardiac arrest is extremely low (median survival is approximately 8.5%) . Furthermore, many patients who survive, are admitted to the hospital, and survive to be discharged have severe neurological deficits .
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