Heart Attack

WHAT IS IT?
A heart attack occurs when the flow of blood to the heart is blocked, most often by a buildup of fat, cholesterol, and other substances that form a hard deposit called plaque in a heart (coronary) artery. The interrupted blood flow can damage or destroy part of the heart muscle.
Another cause of a heart attack is a spasm in a coronary artery that shuts down blood flow to the heart. A heart attack can also result from a tear in a coronary artery.
A heart attack results when deposits (plaques) form in a coronary artery, limiting blood flow. Some plaques become unstable and rupture. A blood clot forms at the rupture site, blocking blood flow through the artery and to the heart muscle.

Factors that can increase your risk of a heart attack include:

  • Age. Men aged 45 or older and women age 55 or older are at higher risk of a heart attack.
  • Tobacco. Smoking and long-term exposure to secondhand smoke increase the risk of a heart attack.
  • High blood pressure. Over time, high blood pressure can damage the arteries that feed your heart.
  • High blood cholesterol or triglyceride levels. A high level of low-density lipoprotein (LDL, or “bad”) cholesterol is most likely to narrow arteries. A high level of triglycerides, a type of blood fat related to your diet, also ups your risk of a heart attack.
  • Diabetes. Having diabetes, especially uncontrolled diabetes, increases your risk of a heart attack.
  • Family history. If your siblings, parents or grandparents had early heart attacks (by age 55 for male relatives and age 65 for female relatives), you may be at increased risk.
  • Inactivity. An inactive lifestyle can increase your risk.
  • Obesity. Obesity is associated with high blood cholesterol levels, high triglyceride levels, high blood pressure, and diabetes.
  • Stress. How you respond to stress can increase your risk.
  • Illegal drug use. Using stimulant drugs can trigger a spasm of your coronary arteries that can cause a heart attack.

SYMPTOM

  • Pressure, tightness, pain, or a squeezing or aching sensation in your chest or arms that may spread to your neck, jaw or back
  • Nausea, indigestion, heartburn or abdominal pain
  • Shortness of breath
  • Cold sweat
  • Fatigue
  • Lightheadedness or sudden dizziness
Some heart attacks strike suddenly, but many people have warning signs and symptoms in advance. The earliest warning may be recurrent chest pain (angina) that’s triggered by exertion and relieved by rest. It’s caused by a temporary decrease in blood flow to the heart.

WHAT TESTS TO EXPECT
You’ll likely be asked about your symptoms and have your blood pressure, pulse and temperature checked. Tests that may be performed include:
  • Electrocardiogram (ECG). It records the electrical activity of your heart via electrodes attached to your skin. Because injured heart muscle doesn’t conduct electrical impulses normally, the ECG may show that a heart attack has occurred or is in progress.
  • Blood tests. Certain heart enzymes slowly leak into your blood if your heart has been damaged by a heart attack. Samples of your blood may be taken to test for the presence of these enzymes.
  • Chest X-ray. It allows your doctor to check the size of your heart and its blood vessels and to look for fluid in your lungs.
  • Echocardiogram. It can help identify whether an area of your heart has been damaged by a heart attack and isn’t pumping normally or at peak capacity.
  • Coronary catheterization (angiogram). A liquid dye is injected into the arteries of your heart through a long, thin tube (catheter) that’s fed through an artery. The dye makes the arteries visible on X-ray, revealing areas of blockage.
  • Stress test. After a heart attack, a stress test may be performed to measure how your heart and blood vessels respond to exertion. You may walk on a treadmill or pedal a stationary bike while attached to a monitoring device. Or you may receive a drug that stimulates your heart similar to exercise.
  • CT scan or MRI. A computerized tomography (CT) scan or magnetic resonance imaging (MRI) may be used to diagnose heart problems, including the extent of damage from a heart attack.

TREATMENT
With each passing minute after a heart attack, more heart tissue loses oxygen and other vital nutrients and the tissue deteriorates. The main way to prevent heart damage is to restore blood flow quickly.

Medications
Medications given to treat a heart attack include:

  • Aspirin. Take aspirin immediately. It reduces blood clotting, helping maintain blood flow through a narrowed artery. If you have a regular tablet (not coated), chew it before swallowing.
  • Thrombolytics. Also called clot busters, they help dissolve a blood clot that’s blocking blood flow to your heart.
  • Anti-platelet agents. These drugs help prevent new clots and keep existing clots from getting larger.
  • Other blood-thinning medications. Medications such as heparin make your blood less “sticky” and less likely to form clots.
  • Nitroglycerin. This medication can help improve blood flow to the heart by widening (dilating) the blood vessels.
  • Beta-blockers. They help relax your heart muscle, slow your heart rate, and decrease blood pressure, making your heart’s job easier.
  • Angiotensin-converting enzyme (ACE) inhibitors. They lower blood pressure and help reduce stress on the heart.  

Medical procedures
In addition to medications, you may undergo one of the following:

Coronary angioplasty and stenting. A long, thin tube (catheter) is threaded through an artery to the blocked artery in your heart. Once in position, a special balloon is briefly inflated to open the artery. A metal mesh stent may be inserted into the artery to keep it open long term. Some stents are coated with a slow-releasing medication to help prevent another blockage.

Coronary artery bypass surgery. Occasionally, doctors may perform emergency surgery at the time of a heart attack. Or you may undergo bypass surgery after your heart has had time to recover from a heart attack. Bypass surgery involves sewing veins or arteries in place around a blocked or narrowed coronary artery, allowing blood to bypass the narrowed section as it flows to the heart.

CHEST PAIN
People typically equate chest pain with a heart attack, but other problems can trigger chest pain. Often, the underlying cause has nothing to do with your heart.

               Excerpt From: The Mayo Clinic. “Mayo Clinic A to Z Health Guide”.