Heart Attack

A heart attack occurs when the blood flow that brings oxygen to the heart muscle is severely reduced or cut off completely. This happens when coronary arteries that supply the heart muscle with blood become narrowed from a buildup of fat, cholesterol, and other substances collectively called plaque. The gradual accumulation of plaque is a slow process known as atherosclerosis. Over time, this buildup can significantly restrict blood flow to the heart, leading to a heart attack.

What is a Heart Attack?

A heart attack, or myocardial infarction, happens when a part of the heart muscle doesn't receive enough blood. The blockage is usually due to a buildup of fat, cholesterol, and other substances in the coronary arteries. These fatty, cholesterol-containing deposits are called plaques, and the process of plaque buildup is known as atherosclerosis. In some cases, a plaque can rupture and form a clot that blocks blood flow. This lack of blood flow can damage or destroy part of the heart muscle, emphasising the importance of prompt medical attention when symptoms of a heart attack are present.

A heart attack can be classified into two main types based on the severity of the blockage in the coronary arteries and the resulting damage to the heart muscle.

Type 1: ST-Elevation Myocardial Infarction (STEMI)

An ST-elevation myocardial infarction (STEMI) is caused by an acute complete blockage of a medium or large heart artery. This type of heart attack is characterised by ST-segment elevation on an electrocardiogram (ECG) and requires immediate medical attention. The complete blockage of the coronary artery in a STEMI results in more severe and extensive heart muscle damage compared to other types of heart attack.

Type 2: Non-ST Elevation Myocardial Infarction (NSTEMI)

A non-ST elevation myocardial infarction (NSTEMI) is typically caused by a partial blockage of a coronary artery, although some people with NSTEMI may have a total blockage. This type of heart attack does not show ST elevation on an ECG. While still a serious medical emergency, the extent of heart muscle damage in NSTEMI is usually less severe compared to STEMI due to the partial nature of the blockage.

Recognising the signs and symptoms of a heart attack, also known as myocardial infarction, is crucial for seeking prompt medical attention. While some symptoms may be similar in both men and women, there are also notable differences.

Symptoms in Men

• Chest Discomfort: Men often experience discomfort in the centre of the chest that may last for several minutes or come and go. It can feel like uncomfortable pressure, squeezing, fullness, or pain.
• Pain or Discomfort in Other Areas: Symptoms may include pain or discomfort in one or both arms, the back, neck, jaw, or stomach.
• Shortness of Breath: This can occur with or without chest discomfort.
• Other Signs: Men may break out in a cold sweat, experience nausea, or feel lightheaded.

Symptoms in Women

• Chest Pain or Pressure: The leading symptom, similar to men, but women may describe it as pressure or tightness more often.
• Non-Chest Pain Symptoms: Women are more likely to experience nausea, vomiting, sweating, and pain in the neck, jaw, throat, abdomen, or back.
• Shortness of Breath: With or without chest discomfort.
• Extreme Fatigue: Unexplained fatigue is more commonly reported by women.
• Other Symptoms: Indigestion, nausea/vomiting, palpitations, and sleep disturbances.

Symptoms in Diabetic Persons or Those with Other Disease Conditions

• Varied Symptoms: People with diabetes or other conditions may experience milder or different symptoms of heart attack, which can make it harder to recognise a myocardial infarction. For instance, diabetic neuropathy can alter pain perception, leading to less typical symptoms of heart blockage in females and males.
• Silent Myocardial Infarction: Individuals with diabetes are at higher risk for silent heart attack, where there is minimal to no chest pain.

The primary cause of a heart attack is a severe reduction or complete blockage of blood flow to the heart. This is typically due to a buildup of fat, cholesterol, and other substances in the coronary arteries, a condition known as atherosclerosis. When a plaque in the artery ruptures, it can form a clot that obstructs blood flow. Less common causes of heart attack include severe spasms of a coronary artery and certain infections.`

Several factors can contribute to the development of atherosclerosis and increase the risk of a heart attack:

Coronary Artery Disease

A heart attack is mostly caused by coronary artery disease (CAD), characterised by the accumulation of plaques in the heart arteries, leading to atherosclerosis.

Plaque Rupture

A ruptured plaque can form a clot that blocks blood flow, resulting in damage or destruction of part of the heart muscle.

Other Causes

Less common causes of a heart attack include:

• Coronary artery spasms: Temporary contractions of coronary arteries that can reduce blood flow.
• Infections: Certain infections, like COVID-19, can contribute to heart attack.
• Spontaneous coronary artery dissection (SCAD): A rare condition involving a tear in the coronary artery wall.
• Irregular heart rhythms (arrhythmias): Abnormal heart rhythms that can disrupt normal blood flow.

Several health conditions, lifestyle factors, age, and family history can increase the risk of a heart attack. Some of the key risk factors include:

• High blood pressure
• High cholesterol
• Smoking
• Obesity
• Diabetes
• Physical inactivity
• Unhealthy diet high in saturated and trans fats
• Excessive alcohol consumption
• Stress
• Family history of heart disease
• Age (risk increases with age, especially after 45 for men and 55 for women)
• Other Disease Conditions Associated with Heart Attack

Who's at Risk?

• Individuals with a family history of heart disease
• Those with high blood pressure, high cholesterol, or diabetes
• Smokers and those exposed to secondhand smoke
• People who are overweight or obese
• Individuals with a sedentary lifestyle
• Those consuming a diet high in saturated and trans fats
• Excessive alcohol drinkers
• People under high levels of stress
• People with Coronary Artery Disease or CAD (when the arteries that supply blood to the heart become narrowed or blocked due to plaque buildup)
• People with Peripheral Artery Disease or PAD (where the arteries in the legs, arms, or other areas of the body become narrowed or blocked).
• Individuals with diabetes (due to the damage that high blood sugar levels can cause to the blood vessels and nerves.)

A heart attack can lead to various complications, some of which can be life-threatening. These complications may occur immediately after the heart attack or develop over time.

Arrhythmias

Abnormal heart rhythms can develop due to damage to the heart muscle. These can vary from minor palpitations to life-threatening conditions such as ventricular fibrillation.

Heart Failure

A heart attack can weaken the heart muscle, making it difficult for the heart to pump blood effectively. This can lead to heart failure, a condition where the heart cannot meet the body's demands.

Valve Problems

Damage to the heart valves can occur after a heart attack. This damage may lead to leaks or narrowing of the valves, which can affect blood flow.

Cardiogenic Shock

In severe cases, a heart attack can cause cardiogenic shock. This condition occurs when the heart is unable to pump enough blood to meet the body's needs, potentially leading to organ failure, and is considered a life-threatening emergency.

Pericarditis

Inflammation of the pericardium, the sac surrounding the heart, can occur after a heart attack.

Aneurysm

In rare cases, a heart attack can cause a weakened area in the heart wall to bulge or rupture, leading to an aneurysm.

Preventing heart attack involves a combination of lifestyle changes, managing risk factors, and regular medical check-ups. Here are some key strategies:

Healthy Diet

Eating a heart-healthy diet is crucial. This includes consuming foods low in saturated fat, trans fat, and sodium. Focus on eating plenty of fresh fruits, vegetables, whole grains, fish (especially oily fish), nuts, legumes, and seeds. The Mediterranean and DASH diets are examples of eating plans that can help lower blood pressure and cholesterol levels, reducing the risk of myocardial infarction.

Physical Activity

Regular physical activity is essential for maintaining heart health and preventing a heart attack. Aim for at least 2½ hours (150 minutes) of moderate-intensity aerobic physical activity or 1 hour and 15 minutes (75 minutes) of vigorous-intensity aerobic physical activity per week. Additionally, include muscle-strengthening activities at least two days a week. Exercise helps control weight, reduce blood pressure, and improve cholesterol levels - all factors that lower the risk of heart attack, especially in women who may have atypical symptoms of heart blockage.

Tobacco Use

Quitting smoking and avoiding secondhand smoke are critical for heart attack prevention. Smoking significantly increases the risk of heart attack and stroke, and even minimal smoking can have detrimental effects. Quitting smoking is one of the most important steps in preventing the various types of heart attack.

Diagnosing a heart attack involves several steps to quickly identify and treat the condition. Recognising the symptoms is the first crucial step.

Symptom Recognition

Common heart attack symptoms include chest pain or discomfort, shortness of breath, pain or discomfort in the arms, back, neck, jaw, or stomach, cold sweat, nausea, and lightheadedness. Women are more likely to experience atypical symptoms like shortness of breath, nausea/vomiting, and back or jaw pain without chest discomfort. Prompt medical attention is vital if these heart attack symptoms in women or men are present.

Diagnostic Tests

Several tests help diagnose a heart attack:

Electrocardiogram (ECG)

This records the heart's electrical activity, helping detect abnormalities suggesting a heart attack.

Blood Tests

These measure levels of cardiac enzymes and troponins that leak into the bloodstream when the heart muscle is damaged.

Chest X-ray

This visualizes the heart, lungs, and blood vessels to check for abnormalities.

Echocardiogram

This uses sound waves to create a moving picture of the heart to assess damage and pumping function.

Coronary Angiography

This involves injecting dye into the coronary arteries to detect blockages on X-rays.

Cardiac CT or MRI

These scans provide detailed images of the heart to evaluate damage.

Treatment for a heart attack depends on the type and severity, but immediate intervention is critical to restore blood flow to the heart and prevent further damage. Here are the main treatment approaches:

Immediate Treatment

In the event of a heart attack, immediate treatment is crucial to minimise damage to the heart muscle and improve the chances of survival. This may include the administration of oxygen, aspirin to prevent further blood clotting, and nitroglycerin to improve blood flow to the heart. Pain relief medications, such as morphine, may also be given to manage chest pain and discomfort.

Medications

Various medications can be used to treat heart attack and prevent future myocardial infarctions. These include:

• Thrombolytic medications: These medications help dissolve blood clots that are blocking the coronary arteries, restoring blood flow to the heart muscle.

• Antiplatelet agents: Medications like aspirin and clopidogrel prevent blood platelets from sticking together and forming clots, reducing the risk of further heart attack.

• Beta-blockers: Beta-blockers, such as metoprolol and propranolol, slow the heart rate and force of contraction, lowering blood pressure and reducing the heart's workload.

• ACE inhibitors and ARBs: ACE inhibitors, like lisinopril, and angiotensin receptor blockers (ARBs), such as valsartan, lower blood pressure by widening blood vessels, thus reducing the heart's workload and helping prevent heart failure from worsening.

• ARNIs: Angiotensin-receptor neprilysin inhibitors (ARNIs), like sacubitril/valsartan, combine a neprilysin inhibitor and an ARB to improve artery opening, blood flow, reduce sodium retention, and decrease strain on the heart.

• Calcium channel blockers: Calcium channel blockers, such as amlodipine and verapamil, interrupt calcium movement into heart and blood vessel cells, relaxing blood vessels and decreasing the heart's pumping strength.

• Vasodilators: Vasodilators like nitroglycerin and isosorbide dinitrate, which can include nitrates, widen blood vessels, making it easier for blood to flow, increasing blood and oxygen supply to the heart, and reducing the heart's workload.

• Statins: These medications lower cholesterol levels, particularly LDL (bad) cholesterol, which can contribute to the formation of plaques in the coronary arteries.

Note: Some medications, particularly effervescent or soluble formulations of certain medications like paracetamol/acetaminophen, can contain high amounts of sodium. This can increase the risk of cardiovascular disease and heart attack. It is advised to avoid sodium-containing formulations when possible and opt for non-sodium-containing alternatives.

Surgical Interventions

In some cases, surgical interventions may be necessary to treat a heart attack and restore blood flow to the heart muscle. These include:

• Coronary angioplasty and stenting: This procedure involves inserting a small balloon into the blocked coronary artery and inflating it to open up the artery. A stent, a small wire mesh tube, may then be placed to keep the artery open and maintain blood flow.

• Coronary artery bypass graft (CABG) surgery: This operation involves using a blood vessel from another part of the body to bypass the blocked coronary artery, restoring blood flow to the heart muscle.

Lifestyle Changes

Following a heart attack, making lifestyle changes is essential to prevent future myocardial infarctions and improve overall cardiovascular health. This includes adopting a heart-healthy diet, quitting smoking, maintaining a healthy weight, managing stress, and engaging in regular physical activity as recommended by a healthcare provider.

If you experience any of the following symptoms, it is essential to seek medical attention promptly:

• Chest Pain or Discomfort: If you experience chest pain or discomfort that lasts for more than a few minutes or goes away and comes back, it could be a sign of a heart attack or other serious cardiovascular condition.

• Shortness of Breath: Difficulty breathing or feeling winded even when you are at rest can indicate a heart problem or other underlying health issue.

• Upper Body Discomfort: Pain or discomfort in the arms, back, neck, jaw, or stomach can be a sign of a heart attack, especially if accompanied by chest pain or shortness of breath.

• Cold Sweat, Nausea, or Lightheadedness: Breaking out in a cold sweat, feeling nauseous, or experiencing lightheadedness along with chest pain or discomfort can be additional signs of a heart attack.

• Heart attack, also known as myocardial infarction, occur when the blood flow to the heart is blocked, causing damage to the heart muscle.

• Common symptoms of a heart attack include chest pain or discomfort, shortness of breath, upper body discomfort, cold sweat, nausea, and lightheadedness.

• Women may experience additional or different symptoms, such as unusual fatigue, sleep disturbances, and anxiety.

• Risk factors for heart attack include high blood pressure, high cholesterol, smoking, obesity, diabetes, physical inactivity, and a family history of heart disease.

• Treatment for heart attack may involve medications such as beta-blockers, ACE inhibitors, ARBs, ARNIs, calcium channel blockers, and vasodilators.

• Some medications, particularly those containing sodium, can increase the risk of cardiovascular disease and heart attack.

• If you experience symptoms of a heart attack, seek medical attention immediately, as prompt intervention can significantly improve outcomes.