Understanding Angina And Its Underlying Pathophysiology ✓ Solved

Understanding Angina and Its Underlying Pathophysiology

Angina is a coronary artery disease that occurs when there is an imbalance between oxygen supply and demand in the myocardium (McCance & Huether, 2019). When supply is impaired and doesn’t meet demand, myocardial ischemia happens (McCance & Huether, 2019). There are two important concepts of accumulation of fatty streaks and endothelial dysfunction that explain the process of coronary artery disease (McCance & Huether, 2019). The coronary artery is made up of vascular smooth muscle and lined with vascular endothelium (McCance & Huether, 2019). With normal function, low-density lipoproteins (LDL) circulate throughout the arteries and deliver triacylglycerol fuel to tissues (McCance & Huether, 2019).

However, under abnormal circumstances, a certain percentage of LDLs are damaged by oxidative processes (McCance & Huether, 2019). Normally, macrophages ingest the oxidized LDL, attempting to clear waste, but these become engorged and transform into foam cells (McCance & Huether, 2019). These foam cells accumulate and lodge within the layer of vascular smooth muscle, forming fatty streaks visible as plaques in the arterial walls (McCance & Huether, 2019). As these foam cells and lipid deposits enlarge, they can rupture through the endothelial lining, causing damage and initiating inflammatory responses resulting in atherosclerosis (McCance & Huether, 2019). The damaged endothelial cells are unable to produce sufficient nitric oxide, impairing vasodilation and leading to narrowed coronary arteries (McCance & Huether, 2019).

This narrowing restricts blood flow, diminishes oxygen delivery to cardiac tissues, and precipitates angina or heart attack. Angina, characterized by chest discomfort caused by decreased blood flow and myocardial ischemia, serves as a clinical symptom of underlying coronary artery disease (Mayo Clinic, 2020). There are different types of angina, primarily stable and unstable, each with distinct characteristics and implications for management.

Stable Angina

Stable angina is not a heart attack and involves transient ischemia without permanent tissue damage or infarction (American Heart Association, 2020). Patients typically describe a sensation of pressure, fullness, squeezing, or pain centered in the chest area, often radiating to other regions such as the neck, jaw, shoulder, or arm (American Heart Association, 2020). This type of angina is usually predictable and triggered by exertion, emotional stress, cold temperatures, or heavy meals. It subsides with rest and responds well to medication (American Heart Association, 2020). High cholesterol levels and fixed atherosclerotic obstructions primarily cause stable angina, reflecting the presence of significant plaque buildup that reduces coronary perfusion (Huff, Boyd, & Jialal, 2020).

Unstable Angina

In contrast, unstable angina is unpredictable, occurring even at rest, with sudden and severe chest pain that may last longer and intensify over time (American Heart Association, 2020). Pain pattern changes are common, and it does not respond well to typical medications. The pathophysiology often involves rupture of a vulnerable plaque, leading to the formation of thrombi that occlude coronary arteries, thereby precipitating myocardial infarction (Ginghina et al., 2009). Patients experiencing unstable angina are at higher risk of heart attack and necessitate urgent medical care. Electrocardiograms during attacks often reveal ST-segment depression, indicating myocardial ischemia (Ginghina et al., 2009).

Diagnostic Approaches and Management

Healthcare providers utilize stress testing and coronary angiography to evaluate and diagnose angina (Mayo Clinic, 2020). Stress tests involve monitoring cardiac activity during exercise to identify ischemic changes, while angiograms visualize arterial blockages and plaque characteristics. Management aims to relieve symptoms, reduce the frequency of anginal attacks, and prevent myocardial infarction. Pharmacologic interventions include nitrates such as nitroglycerin, long-acting nitrates, and antiplatelet agents like aspirin to inhibit clot formation and improve blood flow (Mayo Clinic, 2020). Lifestyle modifications are equally vital, encompassing smoking cessation, alcohol moderation, weight management, healthy diet, and regular exercise, while avoiding exertion during symptomatic periods, stress, and large meals (Mayo Clinic, 2020).

In addition to medical therapy, invasive procedures like percutaneous coronary intervention (PCI) with stent placement or coronary artery bypass grafting (CABG) are indicated in cases of significant obstructive disease (Mayo Clinic, 2020). These surgical interventions help restore adequate blood flow, alleviate symptoms, and decrease the risk of adverse cardiac events. Continuous monitoring and secondary prevention strategies also involve controlling blood pressure, managing diabetes, and addressing dyslipidemia to prevent disease progression.

Conclusion

Understanding the pathophysiology of angina illuminates the critical role of atherosclerosis and endothelial dysfunction in its development. Effective diagnosis and treatment depend on recognizing the distinct features of stable versus unstable angina, facilitating timely medical intervention. Advances in pharmacological therapy and interventional cardiology continue to improve patient outcomes, emphasizing the importance of comprehensive cardiovascular care and lifestyle modifications. Managing angina effectively not only diminishes symptom burden but also significantly reduces the risk of progression to myocardial infarction, ultimately enhancing quality of life for affected individuals.

References

• American Heart Association. (2020). Unstable Angina. Retrieved from https://www.heart.org
• Ginghina, C., Ungureanu, C., Vladaia, A., Popescu, B. A., & Jurcut, R. (2009). The electrocardiographic profile of patients with angina pectoris. Journal of medicine and life, 2(1), 80–91.
• Huff, T., Boyd, B., & Jialal, I. (2020). Physiology, Cholesterol. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov
• Mayo Clinic. (2020). Angina. Retrieved from https://www.mayoclinic.org
• McCance, K. L., & Huether, S. E. (2019). Pathophysiology: The biologic basis for disease in adults and children (8th ed.). Elsevier.