Mr.
Smith was lifting a heavy piece of furniture when he experienced crushing pain
in his chest, began sweating heavily, and was nauseated. His wife drove him to
the hospital, where he was diagnosed with a myocardial infarction (MI, also
called a heart attack) and given intravenous drugs to dissolve a clot that was
obstructing a major coronary artery. After his hospitalization, Mr. Smith’s
doctor told him that some of his heart muscle had died.
Explain
the pathological processes associated with the term “heart muscle died.”
Discuss and
contrast reversible and nonreversible cell injury. As per your analysis, what
type of cell injury did Mr. Smith sustain and why? Include pathophysiological
processes involved with cell injury.
Expert Solution Preview
Introduction:
The diagnosis of a myocardial infarction (MI) is a serious medical condition that requires urgent attention and appropriate medical interventions. In this question, we will discuss the pathological processes associated with the term “heart muscle died” and differentiate between reversible and non-reversible cell injuries. Based on the analysis of the case of Mr. Smith, we will diagnose the type of cell injury he suffered and explain the underlying pathophysiological processes related to this injury.
Answer:
Death or necrosis of heart muscle cells following an MI occurs due to a lack of oxygen and nutrients supply to the cardiac cells. The obstruction of a coronary artery by a blood clot reduces the blood supply to the heart muscle cells, leading to ischemia. If left untreated, the ischemia can cause irreversible damage to the cardiac muscle, resulting in the death of the cells. The necrotic heart tissue is then replaced by fibrous tissue, which does not contract and compromises the function of the heart.
Reversible cell injury occurs when the cellular injury is not severe or prolonged enough to cause permanent damage to the cells. The cellular damage can be reversed if the underlying cause of the injury is removed, and the cells are provided with adequate nutrients and oxygen. In contrast, non-reversible cell injury results in permanent cellular damage, and the cells cannot be restored to their previous condition.
Based on the given description, Mr. Smith suffered from non-reversible cell injury as some of his heart muscle died. The prolonged ischemia caused by the obstruction of a coronary artery resulted in irreversible damage to the cardiac muscle cells, leading to their death. The pathophysiological processes involved in ischemic cell injury include reduced ATP production, accumulation of calcium ions, oxidative stress, and inflammation. These processes collectively lead to a series of biochemical and molecular events that contribute to cellular damage and eventual death, as seen in the case of Mr. Smith.