What is Plantar Fasciitis? Causes, Symptoms, and Treatment
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The human body is a complex system, and each organ plays a crucial role in maintaining its overall functioning. One such organ is the heart, which requires a steady supply of oxygen and nutrients to function optimally. This supply is ensured by a dense network of vessels known as the coronary system. Understanding the coronary system and its function is critical to understanding ischemic heart disease.
The coronary system consists of veins and arteries that surround the heart's surface, forming a crown-like structure, hence the term coronary arteries. These arteries, rich in arterial blood, supply the heart with oxygen and nutrients, while the veins transport waste blood from the heart to the lungs for purification.
The coronary system is divided into two distinct subsystems: the left coronary system, which primarily supplies blood to the left side of the heart, and the right coronary system, which caters to the right side. Both systems originate from the root of the aorta.
The heart's oxygen consumption is high, even at rest, and much higher than other organs and tissues. The heart muscle tissue, or myocardium, is particularly adept at extracting oxygen from the blood it receives. However, compared to other muscles, the heart has a limited ability to draw energy from anaerobic processes.
Ischemic heart disease, also referred to as myocardial ischemia, is a condition characterized by a discrepancy between the heart's oxygen consumption and the oxygen supply it receives from the coronary arteries. In other words, the heart requires more oxygen than the coronary arteries can provide, leading to a state of hypoxia or oxygen deficiency.
Ischemia can occur due to an increase in myocardial oxygen demand and/or a reduction in coronary flow, leading to an imbalance between the need and availability of oxygen and nutrients. This deficit can be transient or permanent, and permanent deficits can lead to serious damage.
Various pathologies can lead to ischemic heart disease, all of which involve a reduction in blood supply to the heart. The primary cause is atherosclerotic disease affecting the coronary arteries. Atherosclerosis is a degenerative disease that promotes the deposition of fats and other substances in the internal wall of the arteries, reducing the vessel's diameter and elasticity, leading to increased blood pressure and potential vessel rupture.
The consequences of cardiac ischemia depend on several factors, including the importance of the occluded vessel, the duration of occlusion, perfusion by a collateral circulation, and the metabolic and functional state of the myocardium before the interruption of blood flow.
The severity and duration of the ischemia determine whether the cardiac damage is reversible. If ischemia persists, heart cells can withstand the lack of oxygen and nutrients for approximately 20-360 minutes, after which they die. This cellular necrosis is called a heart attack and can be fatal if it involves a large number of cells.
Primary prevention or prophylaxis aims to prevent the onset of ischemic heart disease. It involves the identification and correction of main risk factors such as smoking, diabetes mellitus, dyslipidemia, hypertension, sedentary lifestyle, obesity, and hyperhomocysteinemia.
If ischemic heart disease has already manifested, there are medications that can control the disease's progression and reduce the risk of new serious ischemic episodes. These include nitrates, beta blockers, and calcium antagonists.
Understanding ischemic heart disease is crucial for prevention and treatment. By understanding the coronary system and the factors that can lead to ischemic heart disease, individuals can take steps to maintain their heart health and reduce their risk of serious complications.