The blockage can be sudden and occur in one instant, or it may come and go over a period of time.
The condition occurs due to the buildup of fatty deposits in and on the walls of the coronary arteries. These arteries are responsible for delivering oxygen and nutrients to heart muscles.
Heart muscles need a steady and constant supply of oxygen-rich blood to function. A blood clot is the most common cause of a blocked coronary artery.
Angina and heart attacks are types of acute coronary syndrome.
Acute coronary syndrome is used to describe three types of coronary artery disease:
- Unstable angina
- Non-ST-segment elevation myocardial infarction or heart attack (NSTEMI)
- ST-segment elevation myocardial infarction or heart attack (STEMI)
If the supply of oxygen to the cells becomes too low, the cells of the heart muscles can die.
The lack of blood supply to any tissue is called ischemia. The death of the cells results in damage to muscle tissue, and this is a heart attack or myocardial infarction.
In some cases, the cells do not die, but damage due to an inadequate supply of oxygen results in heart muscles that do not work correctly or efficiently. The problem may be temporary or permanent. Unstable angina is the term used to describe the condition when acute coronary syndrome does not lead to cell death.
The location of the blockage, the length of time that the blood flow is blocked, and the amount of damage that occurs determines the type of acute coronary syndrome. Doctors classify the coronary syndromes based on:
- The presence of certain substances in the blood released by the damaged heart
- Electrocardiography (ECG) results
Proper classification is especially important when it comes to choosing the right treatment.
Risk factors associated with acute coronary syndrome include smoking and obesity.
The signs and symptoms of acute coronary syndrome generally begin quickly, sometimes without warning, and can alert a person that something is wrong. Common symptoms include:
- Chest pain or discomfort
- Pain or discomfort in one or both arms, the back, jaw, neck, or stomach
- Shortness of breath
- Dizziness or feeling lightheaded
- Nausea or vomiting
These symptoms are very serious and a person should seek emergency treatment immediately. Chest pain caused by acute coronary syndromes can come on suddenly without warning, which occurs during a heart attack.
In other cases, the pain can be unpredictable and get noticeably worse even after rest, which is a symptom of unstable angina. Chest pain or discomfort is typically the most common symptom of acute coronary syndrome, but signs and symptoms vary depending on age, sex, and the presence of other medical conditions.
There are certain risk factors associated with acute coronary syndrome that people should be aware of. Risk factors include:
- Older age - men of 45 years or older, women aged 55 years or older
- High blood pressure or cholesterol
- Lack of physical activity
- Unhealthy diet, obesity, or overweight
- Family history
To make a quick and accurate diagnosis, a doctor will perform tests as well as inquire about any symptoms and previous medical history. Typical tests include:
- Electrocardiogram (ECG): This test measures the electrical activity in the heart via electrodes attached to the skin. Abnormal or irregular impulses may indicate poor heart function due to a lack of oxygen to the heart. Certain electrical signal patterns may also help to indicate the location of a blockage.
- Blood tests: Certain enzymes may be detectable in the blood if cell death results in damage to the heart tissue. A positive result indicates a heart attack.
- Cardiac perfusion scan: This scan can show if the heart is getting enough blood and can check areas of damage after a heart attack.
Information from these tests, as well as the actual signs and symptoms, are used to help diagnose acute coronary syndrome and determine whether it should be classified as a heart attack or unstable angina.
Doctors may use other tests to determine if additional treatment is needed or if there are additional heart problems present.
Some doctors may order a person to wear a Holter monitor, which records the heart's electrical activity for 24 hours. The monitor helps to detect whether the person has abnormal heart rhythms or periods of inadequate blood supply that may not have any symptoms.
Additional tests may be ordered to rule out other causes as well as help to treat the person better.
Acute coronary syndrome is a medical emergency and medical attention should be sought immediately.
This is a medical emergency. Immediate treatment is ordered for acute coronary syndrome. The short-term goals include relieving pain and improving blood flow to help restore heart function as quickly as possible.
Long-term goals include improving overall heart function, managing risk factors, and lowering the risk of a heart attack. Typical treatment includes a combination of medical drugs and surgical procedures.
- Antiplatelet drugs
- Beta blockers
- Angiotensin-converting enzyme (ACE) inhibitors
- Angiotensin receptor blockers (ARBs)
People who call the emergency services may be instructed to take or be given aspirin in the ambulance. If medications fail to alleviate the problems and restore proper blood function, angioplasty and stenting as well as coronary bypass surgery may be necessary.
In some people, acute coronary syndrome may be prevented. Heart disease can lead directly to acute coronary syndrome, but those who do not have heart disease can protect themselves by practicing a healthy lifestyle:
- Following a heart-healthy diet: Eating a diet that includes fruits, vegetables, whole grains, and lean protein.
- Not smoking: Those who smoke can try medicines and counseling to help them quit.
- Being active: Engaging in regular exercise to stay physically fit. People should aim for moderate exercise at least 2-3 hours a week.
- Paying attention to the numbers: People should know their blood pressure and cholesterol levels and understand what the numbers mean as well as the optimum range.
- Maintaining a healthy weight.
- Drinking alcohol in moderation: Drinking more than one or two alcoholic drinks per day can raise blood pressure.
People who have had problems such as a heart attack in the past may also be instructed to take one baby aspirin in addition to their daily medication. Aspirin helps to prevent platelets from forming clots and helps to reduce the risk of a second heart attack by around 22 percent.
With lifestyle changes and the right medication, it is possible to prevent acute coronary syndrome or to treat it and lead a normal life.