A heart attack, also known as a myocardial infarction, can occur when the heart is not receiving the blood supply and oxygen it needs to function properly. A common cause is when the coronary artery is blocked by a blood clot from receiving its supply of oxygenated blood. A portion of the heart's muscle can die, causing intense chest pain.
Definition & Facts
During a heart attack, a muscle of the heart loses its oxygenated blood supply. Blood flow needs to be restored as quickly as possible or that part of the heart's muscle will deteriorate and die. A blood clot may cause a heart attack as it can block the coronary artery's blood supply to the heart muscle. Complications arising from a heart attack include heart failure and ventricular fibrillation.
Symptoms & Complaints
Other symptoms include pain that radiates to the back, neck, arms and the jaw. Someone can experience pain in these areas of the body without having any chest pain. A person may also experience shortness of breath, difficulty breathing, nausea, vomiting and rapid heart rate or irregular heartbeat.
Additional signs of a heart attack can include:
- Anxiety - feeling a sense of foreboding, as in a panic attack
- Lightheadedness - feelings of dizziness can occur combined with chest tightness
- Sweating - skin may become cold and clammy
Women may experience the symptoms of myocardial infarction differently from men. Women's symptoms may not include chest pain, but rather include feelings of heartburn, exhaustion, flutters, coughing and a loss of appetite.
A heart attack can occur due to a number of different causes. Coronary heart disease is the main cause of most heart attacks. This involves the narrowing of a coronary artery due to atherosclerosis or the buildup of fatty plaque calcifications one of which is usually cholesterol.
When a person experiences a heart attack, a plaque may break open and allow cholesterol into the bloodstream, forming a clot where a rupture takes place. If this clot is big enough, it may block blood flow to the coronary artery, causing myocardial infarction.
Another reason for a heart attack is if the coronary artery is spasming, thereby blocking blood flow to the heart muscle, or there may be a tear in the coronary artery.
There are a number of risk factors that contribute to the causes of heart attacks. Some risk factors for myocardial infection include high blood pressure, using illegal drugs like cocaine, high cholesterol, obesity, smoking, and diabetes. Stress can be a link to heart attacks, as can leading a sedentary lifestyle and having a family history of heart disease.
Diagnosis & Tests
A heart attack can be diagnosed by a cardiologist using a variety of tests to pinpoint where there are blockages and damage to the heart tissue. An electrocardiogram (EKG or ECG) is a test that will show any damage to the heart muscle and where that damage exists. An EKG records the electrical activity of the heart, showing how fast it is beating and whether its rhythm is steady or irregular. This test will also measure the electrical signals passing through the parts of the heart and records their strength and timing. An EKG will exhibit the signs of heart damage from coronary heart disease and whether there has been a previous heart attack or if a current one is occurring.
Other diagnostic tests include blood tests and an angiography. Blood tests can show a higher-than-normal amount of certain proteins in the bloodstream that can result from heart muscle death. A coronary angiography displays the interior of the coronary arteries by using a dye placed into the bloodstream and x-rays. If done while a heart attack is ongoing, the blockages in the coronary artery can often be illuminated as the x-rays show the blood flowing through the heart and blood vessels.
Treatment & Therapy
If a myocardial infarction is suspected, it can be treated immediately with aspirin, nitroglycerin, and oxygen therapy. The aspirin will help stave off any more blood from clotting. Nitroglycerin allows for your heart to not work as hard and eases the flow of blood throughout the arteries. Oxygen therapy restores blood flow to your vessels and organs and allows a person to breathe more easily.
There are also medicines available to dissolve blood clots that are causing the heart attack. The use of these drugs is called thrombolytic therapy and they should be taken within a few hours of when the symptoms of a heart attack began, or as soon as possible.
Another treatment is percutaneous coronary intervention (PCI), which is a procedure to open narrowed or blocked arteries using a fine flexible catheter with a balloon. This tube is taken through a blood vessel in the groin and threaded up to the blocked artery where it is then inflated to restore blood flow. At this point, a stent may be put into place to keep the vessel open and prevent future blockages. Some drug therapies for heart attack include angiotensin-converting enzyme (ACE)) inhibitors to lower blood pressure, anti-clotting drugs, anticoagulants, beta blockers, and statins. A coronary artery bypass graft surgery procedure can also give a different route for blood to flow to the heart muscle.
Prevention & Prophylaxis
Maintaining a heart-healthy diet includes incorporating fat-free or low-fat dairy products, foods high in omega-3 fatty acids, fruits, legumes, vegetables, and whole grains. To keep the heart healthy, avoid eating too much red meat, palm or coconut oils and overly sugar-laden foods and drinks. Both saturated fats and trans fats contribute to high blood cholesterol levels. Exercise on a regular basis, managing stress levels and keeping an eye on blood pressure and cholesterol levels all contribute to the prevention of heart attacks.