• Sarah Kosoy

Heart Attacks and Strokes--What About ‘Em?

Picture this: You're studying for that test about the circulatory system. Your teacher assigns you to research both strokes and heart attacks, but you do not know where to start. Sounds familiar? You’ve most certainly heard the words, “heart attack” and “stroke” more than once in your life. You probably know that a person suffering from either one of these medical emergencies may die if not tended to quickly enough, but you are unsure of the mechanisms behind such catastrophic events. So what exactly are heart attacks and strokes and what is the aftermath of both illnesses?

A heart attack, also referred to as myocardial infarction, occurs when oxygenated blood flow traveling from the coronary arteries to the heart is severely reduced, or cut off instantaneously. The heart muscle relies on oxygen for its survival, so the lack of this essential element causes severe damage to the function of the organ. Atherosclerosis, or a buildup of fat and cholesterol in the coronary arteries, is one common culprit for the onset of myocardial infarction. A diet high in saturated fats causes the body’s blood cholesterol and lipid levels to rise significantly. As a result, these materials become in excess and tend to deposit within the walls of blood vessels, particularly arteries. Over time, the continued buildup of plaque clogs arteries to the point where blood simply cannot pass through them. The blood of the affected area then clots around the plaque. Eventually, the lack of blood flow provokes oxygen deprivation, also known as ischemia, which severely damages the tissues of the heart. Now might be a good time to start eating those greens!

The aftermath of a heart attack is dependent on (1) the size of the area affected by clotted blood and (2) the length of time it takes to treat the suffering patient. Larger areas starved of essential oxygen and nutrients tend to cause more destruction to the heart muscle than that of smaller affected regions. At the same token, the longer the heart goes without oxygen, the more severe damage that results. Assuming that a patient has a happy ending and makes a successful recovery, a scar tissue will form over the injured area within eight weeks of the incident. Though this essentially mends the damage, scar tissue is not as strong and effective at pumping blood as non scar tissue. As a result, recovering patients’ heart function will be below normal levels. Additionally, most heart attack survivors will develop coronary artery disease, which is the narrowing of blood vessels resulting from a buildup of plaque. Patients afflicted with this illness are administered medication that must be taken for the rest of their lives.

Like heart attacks, some strokes result from a restriction of oxygenated blood travelling to a particular region. These types of strokes are referred to as ischemic, similar to the ischemia that occurs when the heart muscle is starved of oxygen. Strokes are also provoked by the bursting of blood vessels. These are often called hemorrhage strokes. Unlike myocardial infarction, however, the disruption of blood flow occurs in vessels travelling to the brain and not the heart. The brain requires about 20% of the body’s entire oxygen supply to function efficiently, so you can probably imagine the effects that severely reducing oxygen transport will have on this small, but mighty organ.

Unfortunately, it is inevitable that strokes of all magnitudes will cause some sort of damage, or even disability to the body. Depending on where the stroke occurs, injury can range from memory loss to complete lack of mobility. As an example, strokes located in the back of the brain will likely provoke vision loss, since the vision centers are found in this region. It is also important to note that damage on one side of the brain will affect the opposite side of the body, similar to how a mirror flips the features of its subject. There is one exception to this rule, however. If you’ve taken anatomy class before, you may recall that the brain stem controls the message flow to both sides of the body. As a result, strokes of the brainstem cause the most extensive disability, leaving patients unable to speak or move below the neck. On a much happier note, there are ways to prevent the onset of strokes. By simply consuming a diet, low in salts and trans fats and by partaking in moderate exercise often, you can avoid damage to your blood vessels. Embracing a healthy lifestyle is essential to long term health and it is never too late to start!

Today, you’ve learned of the science behind both heart attacks and strokes. You are now equipped with the tools to create an awesome research project. Hopefully you took helpful notes for your assignment because there are plenty of significant points throughout this article. Happy studying and good luck on the project!