The heart is the hardest working muscle in the human body. Located almost in the center of the chest, the adult human heart is about the size of a fist.
“At an average rate of 80 times a minute, the heart beats about 115,000 times in one day or about 42 million times in a year,” said Shazib N. Khawaja, MD, FACC, FSCAI, an interventional cardiologist with Tanner Heart & Vascular Specialists, a Tanner Medical Group practice. “In a 70-year lifetime, an average human heart will beat more than 2.5 billion times. Even when a person is at rest, the heart continuously works hard.”
How the Heart Works
The cardiovascular system is made up of the heart and blood vessels. It's responsible for circulating blood throughout your body to supply the tissues with oxygen and nutrients.
The heart is the muscle that pumps blood filled with oxygen and nutrients through the blood vessels to the body tissues. It is comprised of:
- Four chambers (two atria and two ventricles) that receive blue (deoxygenated) blood from the body and pump out red (oxygen-rich) blood
- Blood vessels, which include a network of arteries and veins that carry blood throughout the body
- Four valves to prevent backward flow of blood
- An electrical system that serves as a natural pacemaker and stimulates contraction of the heart muscle
What is a Heart Attack?
During a heart attack, or myocardial infarction, one of the coronary arteries that supply the heart with oxygen becomes blocked, depriving the muscle of oxygen and causing the chest pain and pressure that are so synonymous with heart attacks.
The blockage is often a result of atherosclerosis — a buildup of plaque composed of fat deposits, cholesterol and other substances. When a plaque ruptures, a blood clot quickly forms. The blood clot is the actual cause of the heart attack.
As the heart muscle is deprived of oxygen, the cells that make up the muscle begin to die. Muscle is lost by the minute during a heart attack, and if blood is not restored to the heart quickly, it can lead to irreversible damage to the heart and, sometimes, even death. Limiting damage to the heart – and possibly saving the life of the patient – requires opening the blocked coronary artery to restore the flow of oxygen-rich blood to the cells of the heart muscle. To do this, facilities across the country, including Tanner Heart and Vascular Center at Tanner Medical Center/Carrollton, use a procedure called cardiac angioplasty/stent placement.
"During cardiac angioplasty, a small incision is made, often in the leg or arm, and a thin tube called a catheter is inserted into a large artery," said Dr. Khawaja. "The catheter is then navigated to the heart arteries, and a balloon and/or stent – a small tube made of wire mesh – is inserted in the heart artery at the site of the blockage. The balloon or stent is inflated to open the blockage and restore blood flow."
Blockages in the coronary arteries can be caused by high levels of bad cholesterol, which turns into plaque lining the walls of arteries, causing them to narrow or become blocked over time. The surface of the plaque in the artery may also rupture, causing a blood clot to form and leading to a heart attack.
Anyone experiencing a heart attack and arriving at any of Tanner’s 24-hour emergency departments will activate Tanner’s Heart Alert System. If at Tanner Medical Center/Villa Rica or Higgins General Hospital in Bremen, the patient will immediately be transferred to Tanner Heart and Vascular Center in Carrollton where specially-trained physicians, nurses and technologists will oversee their care.
Angioplasty and stenting can also be used to treat other vascular conditions as well, such as peripheral artery disease (PAD).
Heart Attack Warning Signs
The following are the most common symptoms of a heart attack. However, each individual may experience symptoms differently. Symptoms may include:
- Severe pressure, fullness, squeezing, pain and/or discomfort in the center of the chest that lasts for more than a few minutes or that goes away and comes back
- Pain or discomfort that spreads to the shoulders, neck, arms or jaw
- Chest pain/pressure that increases in intensity
- Chest pain/pressure that is not relieved by rest or by taking nitroglycerin (NTG)
- Chest pain/pressure that occurs with any/all of the following (additional) symptoms:
- Sweating, cool, clammy skin and/or paleness
- Shortness of breath
- Nausea or vomiting
- Dizziness or fainting
- Unexplained weakness or fatigue
- Rapid or irregular pulse
Although chest pain is the key warning sign of a heart attack, it may be confused with indigestion, pleurisy, pneumonia or other disorders. The symptoms of a heart attack also may resemble other medical conditions or problems. Always consult your healthcare provider for a diagnosis.
Know What to Do
If you or someone you know exhibits any of the above warning signs:
- Recognize the symptoms and act at once. Don’t deny or ignore what is happening.
- Stop any activity and sit or lie down.
- If you have nitroglycerin (NTG), take it as directed.
- If the pain lasts more than a few minutes, call emergency medical services at 911.
Dr. Khawaja is board-certified in interventional cardiology and vascular medicine and endovascular intervention and is an interventional cardiologist with Tanner Heart & Vascular Specialists and the medical operations leader of cardiac services for Tanner Health System. More information about the practice is available online at www.HeartAndVascularSpecialists.org.