Heart Attack Overview
Function of the cardiovascular system
The heart is an incredibly powerful organ. It can beat more than 100,000 times a day, pumping approximately
2,000 gallons of blood through a 60,000-mile network of vessels in the body. The blood that the heart pumps
provides nutrients, including oxygen, to all the body’s organs.
What is a heart attack?
Like all the body’s organs, the heart needs oxygen to work. A heart attack occurs when the blood that brings
life-giving oxygen to the heart muscle is significantly reduced or cut off completely.
Coronary arteries supply the heart muscle with oxygen-rich blood. Over time, arteries can narrow from a buildup of fat, cholesterol, and other substances that, together, are called plaque. This process is called atherosclerosis and has no obvious symptoms. Plaques can sometimes rupture. This results in the formation of a blood clot. Blood clots can either reduce or completely block blood flow, leading to acute coronary syndrome (ACS).
Some patients may not be familiar with ACS, but they may know the 2 component names—unstable angina and
heart attack. When the blood flow that brings oxygen to the heart muscle is severely reduced, but not completely cut off, this is called unstable angina, which does not permanently damage the heart muscle. When the blood flow is severely reduced or cut off completely and there is heart muscle damage, the result is a heart attack, or myocardial infarction (MI).
- In the United States, a person has a heart attack approximately every 42 seconds
- About 735,000 Americans have heart attacks every year
- For 525,000 of these Americans, this is a first-time heart attack
- For the remaining 210,000 people, a heart attack is a recurrent event
Significance of a heart attack
When a heart attack occurs, the portion of the heart muscle that lost its supply of blood can be permanently
damaged as a result of a lack of oxygen. Scar tissue forms at the site of the injured muscle within a few weeks after a heart attack. The scar tissue may not contract or pump as efficiently, making patients more susceptible to an irregular heartbeat, commonly referred to as arrhythmia.
Medications that may be prescribed after a heart attack
Medication is given after a heart attack to maintain or improve cardiac function and prevent a recurrent heart attack. A physician will prescribe medication based on the type of ACS event that occurred. Each medication has a different purpose, such as:
- Preventing blood clots
- Decreasing heart rate
- Treating high cholesterol
- Treating high blood pressure
- Relaxing blood vessels
Procedures and treatments that may be administered at the hospital during and after a heart attack
Procedures and treatments that restore blood flow after a heart attack include:
- Coronary artery bypass grafting (CABG), a procedure to bypass a blocked blood vessel in the heart
- by grafting a healthy one from elsewhere in the body8
- Percutaneous coronary intervention (PCI), a nonsurgical procedure done through the skin that opens a
- narrow or blocked coronary artery to restore blood flow to the heart. Once opened, a stent, a tiny wire mesh
- tube, is placed in the artery to keep it open8
- Thrombolysis, an emergency intravenous (IV) treatment to dissolve dangerous clots in blood vessels and
- improve blood flow