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High cholesterol can have wide-ranging effects—both direct and indirect—on your heart and several other organs served by your vascular system. As cholesterol builds in the arteries of your heart, brain, and throughout your body, it usually does so silently. In some cases, the first signs of atherosclerosis may be a cardiovascular event, such as a heart attack or stroke.
Acute Coronary Syndrome
Experts use the term “acute coronary syndrome” to describe situations in which atherosclerotic plaque accumulation or ruptures cause the narrowing or blocking of one or more coronary arteries, leading to inadequate blood flow to the heart muscle. These situations include stable angina and heart attack.
Atherosclerosis can contribute to heart failure in several ways. Coronary arteries narrowed by atherosclerotic plaque can reduce blood flow to the heart muscle, weakening it.
Also, as arteries outside the heart become narrowed, your heart has to work harder to pump blood. In response, your heart thickens and enlarges to meet the increased demands. Unfortunately, your heart can’t keep up this pace. Over time, the ventricles may stiffen, and the heart muscle may weaken.
In some cases, blood can back up, or congest, in the lungs, abdomen, and lower extremities—the term “congestive heart failure” is derived from this complication. Heart failure patients may experience fatigue and breathing problems, weight gain, swelling in the lower extremities and abdomen due to fluid buildup, and increased/irregular heart rate.
Coronary artery disease and heart attack are risk factors for A-fib, in which irregular electrical impulses cause the heart’s two upper chambers, the atria, to beat rapidly and erratically. As a result, blood isn’t fully pumped out of the heart, but instead pools in the atria, where it can clot. These clots may break free from the atria, travel to the brain, and cause strokes. In fact, A-fib is a leading stroke risk factor.
Carotid Artery Disease
Cholesterol-laden plaque can accumulate in the carotid arteries, the two large arteries on either side of your neck that supply oxygen-rich blood to the brain. Carotid artery disease is a leading risk factor for stroke.
The cerebral arteries of the brain are among the many blood vessels damaged by atherosclerosis, so unhealthy cholesterol levels are a risk factor for stroke.
Most strokes are ischemic strokes, which occur when a blood clot forms and blocks blood flow in the brain. Ischemic strokes also can originate in the carotid arteries. A smaller percentage of strokes are hemorrhagic strokes, caused by ruptured blood vessels inside or on the surface of the brain.
Having high cholesterol also may increase your risk of a transient ischemic attack (TIA), or “mini-stroke,” caused by brief, temporary blockages of blood vessels in or leading to the brain. Research suggests that TIAs increase the risk of stroke and other cardiovascular problems not only for the next several days and weeks, but also over the long term.
When a stroke occurs, the brain tissue served by the affected artery is deprived of blood and begins to die. Strokes and TIAs can cause a variety of sudden symptoms.
High cholesterol and other cardiovascular risk factors not only raise your risk of heart attack and stroke, but they also appear to increase your odds of cognitive disorders.
One of these disorders is vascular dementia, which occurs when damage to the cerebral blood vessels disrupts the connections between areas of the brain or makes them less efficient. Cognitive problems from vascular dementia may occur rapidly after a stroke that affects one of the major brain blood vessels, or they may develop gradually due to cumulative damage from one or more minor strokes in the smaller cerebral vessels.
Vascular dementia is especially characterized by slowed thinking and problems with complex thought processes, such as planning, organizing, and decision-making. It can affect memory, and it also can occur simultaneously with Alzheimer’s disease.
It’s easy to understand how high cholesterol is linked with vascular dementia, and some evidence suggests that it also may be connected with Alzheimer’s disease.
For example, a study involving 74 people (average age 78) found that high levels of HDL and low levels of LDL cholesterol were associated with lower levels of amyloid plaque in the brain. Conversely, the researchers found that the participants with higher LDL levels and lower HDL levels had greater amyloid deposition in their brains.
The processes underlying both Alzheimer’s and vascular dementia may begin years to decades before they ever produce any warning signs. So, your best hope for preventing or delaying the onset of these cognitive disorders may be controlling your cholesterol and other cardiovascular risk factors sooner rather than later.
High cholesterol, diabetes, and other cardiovascular risk factors contribute to the occlusion (blockage) of small veins that transport blood away from the retina. The blockage often occurs where arteries in the retina affected by atherosclerosis press on a retinal vein.
The blockage can lead to bleeding and fluid leakage from the blocked blood vessels. Symptoms include blurry vision or vision loss in all or part of one eye, occurring suddenly or worsening over the course of several hours or days.
Peripheral artery disease occurs when plaques accumulate in the peripheral arteries and limit blood circulation to the legs, feet, arms, and other locations away from the heart. The lack of blood flow jeopardizes the health of your legs and feet; in fact, foot amputation is required in a small percentage of PAD cases.
Some 80 percent of people with PAD also have blockages in their coronary arteries. The AHA estimates that people with PAD face a four to five times greater risk of heart attack and stroke compared to those without the disease.
One of the causes of erectile dysfunction is damage or blockage of the blood supply to the penis due to atherosclerosis. Many experts now consider ED a harbinger of coronary heart disease, since the smaller arteries of the penis are affected up to four years before the larger coronary arteries.
Some evidence suggests that treating high cholesterol may help counter ED. In a meta-analysis of 11 clinical trials, researchers found that men with ED who took cholesterol-lowering statin drugs experienced improvements in their erectile function.
Just as high cholesterol, via atherosclerosis, can restrict blood flow to the penis, it also may affect the vessels supplying blood to the vagina and may potentially cause problems such as vaginal dryness or decreased sex drive or arousal.
For more information about preventing and treating high cholesterol, purchase Managing Your Cholesterol at www.UniversityHealthNews.com.