Heart Attacks

HEART ATTACKS

Heart attacks are almost always the result of progressive coronary artery disease (CAD). In CAD, the arteries that supply blood to the heart become choked with fatty deposits called plaque, which narrows and blocks arteries. This condition is called atherosclerosis. Pieces of plaque when they break free, can form blood clots that may block the flow of blood to the heart. When that happens, the heart muscle does not get the oxygen and the other nutrients that it needs, and parts of the heart may become damaged or die. This is a heart attack, also known as myocardial infarction.

TYPES

Acute coronary syndrome (ACS) is when the arteries that carry blood, oxygen, and nutrients become blocked. Heart attacks are a form of ACS. They occur when the heart doesn't get enough blood supply. A heart attack is also known as a myocardial infarction.

The three types of heart attacks are:

• ST segment elevation myocardial infarction (STEMI) – This is a very serious type of heart attack during which one of the heart's major arteries (one of the arteries that supplies oxygen and nutrient-rich blood to the heart muscle) is blocked. It is a profoundly life-threatening medical emergency, usually associated with a disease process called atherosclerosis (coronary artery disease). Patients experiencing acute STEMI are at risk for developing life-threatening arrhythmias like ventricular fibrillation which causes sudden cardiac arrest. These patients require cardiopulmonary resuscitation (CPR) and defibrillation to restore normal heart rhythm.
• Non-ST segment elevation myocardial infarction (NSTEMI) - Compared to the more common type of heart attack known as STEMI, an NSTEMI is typically less damaging to the heart. An ECG will show the following characteristics for an NSTEMI:
• A partial blockage of the coronary artery
• A depressed ST wave or T-wave inversion
• No progression to Q wave
• Coronary spasm, or unstable angina – A coronary artery spasm is a temporary constriction (tightening) of the muscles in the wall of one of the arteries that sends blood to the heart. A spasm can decrease or completely block blood flow to part of the heart. A spasm that lasts long can bring about chest pain (angina) and even a heart attack (myocardial infarction). Unlike the typical angina, which usually occurs with physical activity, coronary artery spasms often occur while at rest, most often between midnight and early morning.

Both STEMI and NSTEMI heart attacks can cause enough damage to be considered major heart attacks.

CAUSES

A heart attack occurs when one or more of the coronary arteries becomes blocked. Over time, a buildup of fatty deposits, including cholesterol, form material called plaque. This can cause atherosclerosis (the narrowing of the arteries). This condition, called coronary artery disease, is what causes most heart attacks. During a heart attack, a plaque can rupture and spill cholesterol and other substances into the bloodstream. A blood clot forms at the site of the rupture and if the clot is large, it can block blood flow through the coronary artery, starving the heart of oxygen and nutrients (ischemia).

One might have a complete or partial blockage of the coronary artery.

• A complete blockage means an ST elevation myocardial infarction (STEMI).
• A partial blockage means a non-ST elevation myocardial infarction (NSTEMI).

Diagnosis and treatment might be different depending on the type of heart attack.

• Another cause of a heart attack is a spasm of a coronary artery that shuts down blood flow to part of the heart muscle.
• Using tobacco and illicit drugs, such as cocaine, can cause a life-threatening spasm.
• Infection with COVID-19 also may damage the heart in ways that result in a heart attack.

SYMPTOMS

Common heart attack signs and symptoms include:

• Indigestion, nausea, heartburn or abdominal pain
• Fatigue
• Pressure, tightness, pain, or a squeezing or aching sensation in the chest or arms, which may spread to the neck, jaw or the back
• Sudden dizziness
• Shortness of breath
• Cold sweat
• Light headedness

Heart attack symptoms vary

Not all people who have heart attacks experience the same symptoms or have the same severity of symptoms. Whilst some people have mild pain, others may have more severe pain. Indeed, some people have no symptoms at all.

Some heart attacks occur suddenly, however, many people have warning signs and symptoms hours, days, sometimes weeks in advance. Because angina is caused by a temporary decrease in blood flow to the heart, the earliest warning might be recurrent chest pain or pressure (angina) that's triggered by activity and relieved by rest.

RISK FACTORS

The following can increase the risk of a heart attack:

• High levels of stress
• Older age
• Being male
• High cholesterol levels
• High blood pressure
• Obesity
• Diabetes
• Eating processed foods and added fats, sugars, and salt
• Low activity levels
• Genetic factors and family history
• Smoking
• High alcohol intake

Often, a heart attack results from a combination of factors.

In addition, some studies have established that Black Americans, Latin Americans, Native Americans have increased risks of high blood pressure and dying of heart disease, compared with their white counterparts.

People with high blood pressure or a history of heart disease or cardiovascular disease also have an increased risk of a heart attack.

COMPLICATIONS

Complications from a heart attack can vary widely, from mild to life threatening. Some people experience minor heart attacks with no associated complications. This is also known as an uncomplicated heart attack. Other people experience major heart attacks, which would have a wide range of potential complications and may require extensive treatment.

Arrhythmia

An arrhythmia is an abnormal heartbeat and can include:

• Supraventricular tachycardia (Beating too quickly)
• Bradycardia (Beating too slowly)
• Atrial fibrillation (Beating irregularly)

Arrhythmias can develop after a heart attack as a result of damage to the heart muscles because damaged muscles disrupt electrical signals that control the heart.

Some arrhythmias, such as tachycardia, are mild and cause symptoms such as:

• Breathlessness
• Palpitations – the sensation of the heart pounding, fluttering or beating irregularly, felt in the chest or throat
• Chest pain
• Dizziness or lightheadedness
• Fatigue (Tiredness)

Other arrhythmias can be life threatening, including:

• A complete heart block, where electrical signals are unable to travel from one side of the heart to the other, so the heart cannot pump blood properly
• Ventricular arrhythmia, in which the heart begins to beat faster before going into a spasm and stops pumping completely; this is also known as sudden cardiac arrest

These life-threatening types of arrhythmia were a major cause of death during the 24 to 48 hours after a heart attack. Survival rates have however, improved significantly with the the invention of the portable defibrillator (a device that delivers an electric shock to the heart and resets it to the right rhythm).

Mild arrhythmias can usually be controlled with medicine such as beta-blockers.

More troublesome occurrences that cause repeated and prolonged symptoms may need to be treated with a pacemaker. This is an electric device surgically implanted in the chest to help regulate the heartbeat.

Heart failure

Heart failure happens when the heart is unable to effectively pump blood around the body. This can develop after a heart attack if the heart muscle is extensively damaged. It usually happens in the left side of the heart (the left ventricle).

Symptoms of heart failure include:

• Breathlessness
• Tiredness or fatigue
• Swelling in the arms and legs due to a build-up of fluid

Heart failure can be treated with a combination of medicines and, in some cases, surgery.

Cardiogenic shock

Cardiogenic shock is similar to heart failure, but a lot more serious. It develops after the heart muscle has been damaged so much that it can no longer pump enough blood to maintain many of the body's functions.

Symptoms may include:

• Rapid heartbeat
• Mental confusion
• Cold hands and feet
• A decreased need to urinate or not urinating at all
• Pale skin
• Breathing difficulties

A type of medicine called vasopressors may be used. Vasopressors help constrict the blood vessels, which increases blood pressure and improves blood circulation.

After the initial symptoms of cardiogenic shock may have been stabilized, surgery may be required to improve the functioning of the heart. This may include percutaneous coronary intervention (PCI), alongside the insertion of a small pump, known as an intra-aortic balloon pump. This can effectively help improve the flow of blood from the heart. Heart rupture

A heart rupture is an extremely serious but relatively uncommon complication of a heart attack where the heart's muscles, walls or valves split apart (rupture).

DIAGNOSIS

Emergency medical workers will ask about the symptoms and do some tests.

The doctor may order tests that may include:

• EKG. An EKG (also known as an electrocardiogram or ECG) can tell how much the heart muscle has been damaged and where. It can also monitor the heart rate and rhythm.
• Blood tests. Different levels of cardiac enzymes in the blood can indicate heart muscle damage. When those cells are injured, their contents which includes the enzymes spill into the bloodstream. By measuring the levels of these enzymes, the doctor can find out the size of the heart attack and when it began. Tests can also establish troponin levels. Troponins are proteins inside heart cells that are released when the cells are damaged by the lack of blood supply to the heart.
• Echocardiography. This imaging test can be used during and after a heart attack to learn how the heart is pumping and what areas aren't pumping the way they should. The same test can also tell whether any parts of the heart (valves, septum, etc.) may have been injured in the heart attack.
• Cardiac catheterization. One might need cardiac catheterization, also called cardiac cath, during the first hours of a heart attack if medications aren't helping the ischemia or symptoms. The cardiac cath can give an image of the blocked artery and help the doctor decide on a treatment.

TREATMENT

A heart attack is life threatening and needs emergency attention. Nowadays due to effective treatment, many people survive heart attacks.

Delaying treatment, however, would dramatically reduce the chances of survival.

• Call 911 immediately,
• Be ready to explain what has happened and where the patient is
• Stay calm and follow all instructions from the emergency team
• While waiting for the team to arrive, talk to the person, and reassure them that help is on the way.

CPR

If the person stops breathing, take the following steps:

• Do manual chest compressions:
• Lock fingers together and place the base of the hands in the center of the chest.
• Position the shoulders over the hands, lock the elbows, and press hard and fast, to a depth of 2 inches repeatedly
• Continue these movements until the person starts to breathe or move, until someone else can take over, or until the person is exhausted
• If possible, take turns without pausing the compressions
• Use an automatic external defibrillator (AED)

Medical treatment

When the emergency team arrives give the team as much detail as possible about the person's health and what was happening before the event. The team will try to stabilize the person's condition, including providing oxygen.

Many approaches can help, but three common options are:

• Medications, including especially those to dissolve blood clots
• A mechanical method of restoring blood flow to any damaged tissue (Percutaneous coronary intervention).
• Coronary artery bypass grafting, to divert blood around damaged areas of the arteries to improve blood flow (commonly called a heart bypass).

Drugs used during a heart attack may include:

• Aspirin to stop blood clotting that may make the heart attack worse
• Other antiplatelet drugs, such as Plavix (clopidogrel) or Brilinta (ticagrelor) to stop clotting
• Thrombolytic therapy to dissolve blood clots in the heart's arteries

Other treatments for a heart attack

Cardiac catheterization. In addition to making a picture of the arteries, cardiac cath can be used for procedures such as angiography or stent to open narrowed or blocked arteries.

Bypass surgery. The doctors might perform a bypass surgery in the days after a heart attack to restore the blood supply to the heart.

Treatments don't cure coronary artery disease. One can still have another heart attack. But steps can be taken to make it less likely.

RECOVERY

Recovering from a heart attack can take several months, and it's very important not to rush the rehabilitation process.

During the recovery period, the patient will receive help and support from a wide range of healthcare professionals, which may include:

• Dietitians
• Exercise specialists
• Nurses
• Physiotherapists
• Pharmacists

These healthcare professionals will support physically and mentally to ensure the recovery is conducted safely and appropriately.

The recovery process usually happens in stages, starting in hospital, where the patient can be closely monitored and individual needs for the future can be assessed.

After being discharged from hospital, the recovery process can continue at home.

The 2 most important aims of the recovery process are:

• To gradually restore physical fitness so as to resume normal activities (cardiac rehabilitation)
• To reduce the risk of another heart attack

Cardiac rehabilitation

The cardiac rehabilitation programme normally begins at the hospital. Usually, one should also have another session within 10 days of leaving hospital.

A member of the cardiac rehabilitation team will visit the patient in hospital and provide detailed information about the person's:

• State of health and how the heart attack may have affected that
• Type of treatment received and to be continued with
• Medicines that will be needed after leaving hospital
• Specific risk factors that are thought to have contributed to the heart attack
• Lifestyle changes to be made to address those risk factors

Exercise

It is usually recommended that once the patient returns home they rest and only do light activities, such as walking up and down the stairs a few times a day or taking shorts walk.

Gradually, recovering patients must increase the amount of activity they do each day over several weeks. How to do this will depend on the condition of the heart and general health.

The care team can provide more detailed advice about plans to increase activity levels.

The rehabilitation programme should contain a range of different exercises, depending on age and ability. Most of the exercises will be aerobic. These are designed to strengthen the heart, improve circulation and lower blood pressure.

Some examples of aerobic exercises include riding an exercise bike, jogging on a treadmill and swimming.

Returning to work

Most people can return to work after having a heart attack, but how quickly that happens will depend on the patient's health, the state of the heart and the kind of work they do.

If the job involves light duties, such as working in an office, one may be able to return to work in 2 weeks.

However, if the job involves heavy manual tasks or the heart was extensively damaged, it may be several months before one can return to work.

Sex

Recovering patients are usually able to start having sex again once they feel well enough, usually in about 4 to 6 weeks after having a heart attack.

Having sex will not put one at further risk of having another heart attack.

Commonly due to anxiety and the emotional stress associated with having a heart attack, some men have erectile dysfunction after a heart attack. This may make having sex difficult. Aside of that and less commonly, erectile dysfunction is a side effect of a heart medicine called beta blockers.

Driving

As long they do not have other conditions or complications that would disqualify them from driving, many people can now return to driving a week after suffering a heart attack.

But in more severe cases, one may need to stop driving for about 4 weeks.

Depression

Having a heart attack can be frightening and traumatic, and it's common to have feelings of anxiety afterwards. For many people, the emotional stresses can cause them to feel depressed and tearful for a few weeks after returning home from hospital.

If feelings of depression persist, speak to a professional, as patient may have a more serious form of depression.

It's important to seek advice as serious types of depression often do not get better without treatment because a person's emotional state could also have an adverse effect on their physical recovery.