The heart is a pump responsible for distributing blood to the entire body. All of our cells, including those of the heart, require oxygen and nutrients which the blood supplies and a break in the supply of blood to them can cause cell death.
Myocardial infarction (MI) or commonly known as a heart attack, is the interruption of blood supply to the heart, usually by a blood clot, causing some heart cells to die. A heart attack is a serious medical emergency and can be life-threatening.
According to the World Health Organization, heart attacks led to over 9 million deaths in 2016 alone, making it the world’s leading cause of death. A heart attack differs from a cardiac arrest (when the heart malfunctions and stops working).
How does a heart attack occur?
Most patients who suffer a heart attack have atherosclerosis, a condition where the inner walls of major blood vessels that carry oxygenated blood to the heart (called arteries) are lined by cholesterol or fat (called plaques). This leads to the narrowing of the area that blood passes through. The process of atherosclerosis is gradual and has no symptoms.
One of the plaques formed in the blood vessels typically breaks off right before a heart attack (referred to as plaque rupture) causing a blood clot to form at the site it once was. This clot causes the stoppage to the supply of the areas after the blockage, triggering a heart attack.
Although the blood supply can be restored to the areas affected, complications may arise causing the affected heart wall muscle to work sub-optimally or not to work at all.
What are the risk factors for a heart attack?
Risk factors are conditions that increase one’s chances of developing a certain condition. For heart attacks, risk factors are as listed below:
1. Age: Heart attacks are commoner in men older than 45 years of age and women older than 55
3. Diabetes mellitus (and impaired glucose tolerance)
4. High cholesterol levels
6. Family history of heart attacks or heart disease
7. High-fat diet
8. Drug misuse. Examples are cocaine and crystal meth
9. Obesity and physical inactivity
10. Ethnicity: South Asians are thought to have a 40-60% higher risk of CHD-related mortality compared to other populations
What are the signs and symptoms of heart attacks?
A heart attack is a medical emergency as it can be fatal. While most heart attacks cause symptoms, one may not have symptoms in some cases, especially if you are diabetic. The commonest symptoms seen include:
• A squeezing, choking or smothering severe chest pain or heaviness. The chest pain feels like great pressure on the chest that may cause breathlessness, and it can be felt in the neck, left arm, jaw and back
• Typically, the chest pain lasts for longer than 15 minutes and is not relieved by rest or changing positions
• Nausea and Vomiting
• Excessive sweating
• Coughing or wheezing
• Generalised weakness and light-headedness
How is the diagnosis of a heart attack made?
Doctors make the diagnosis of a heart attack from the history of complaints and the physical findings. In addition to these, blood, imaging and other physical tests, chief of which is the Electrocardiogram or ECG (which measures the electrical activity of your heart), are carried out to ascertain the type and location of the heart attack (the part of the affected). These investigations also indicate if there are other medical conditions or concerns.
How are heart attacks managed?
Once the diagnosis of a heart attack is established, immediate stabilisation and resuscitation begin. This typically involves pain management, oxygen delivery, and the administration of medications to help the heart cope better.
Thereafter, treatment is dependent on the type of heart attack you have had (based on the findings on the electrocardiogram or ECG).
Restoration of the blood supply to the affected parts of the heart is carried out via medications (aptly named clot busters) or surgical intervention (via a procedure called percutaneous coronary intervention).
While waiting for an ambulance or transfer to the hospital, it is helpful to chew and then swallow a tablet of Aspirin, if the person having a heart attack is not allergic to Aspirin.
Once the supply is restored, and treatment is completed, medications are offered to reduce the risk of developing another heart attack, and lifestyle modifications (examples are increased physical fitness or smoking cessation) are prescribed.
Complications from a heart attack may also happen after recovery. These may occur immediately after the attack or as late as six weeks after a heart attack, typically causing death or a reduction in quality of life.
How can you prevent a heart attack?
Preventing heart attacks is tied to reducing your risks. These steps are simple and effective. However, they cannot eliminate the chances of developing a heart attack. These steps include:
1. Quit smoking
2. Reduce your alcohol intake
3. Exercise regularly: Do around 30 minutes of aerobic exercises daily or around 150 minutes weekly
4. A healthy balanced diet: Eat low fat, high fibre diet
5. Lose weight, especially if you are overweight or obese
6. Manage any health conditions optimally. Examples are hypertension, kidney disease and diabetes.