What happens during a heart attack?
The heart muscle requires a constant supply of oxygen-rich blood. The
coronary arteries provide the heart with blood. If you have coronary artery
disease, those arteries become narrow and the blood cannot flow as well as
it should. Fatty matter, calcium, proteins and inflammatory cells build up
within the arteries to form plaques of different sizes. The plaque deposits
are hard on the outside and soft and mushy on the inside.
When the plaque's hard, outer shell cracks,
platelets (disc-shaped particles in the blood that aid clotting) come to the
area, and blood clots form around the plaque. If a blood clot totally blocks
the artery, the heart muscle becomes "starved" for oxygen and nutrients
(ischemia) in the region below the blockage. Within a short time, death of
heart muscle cells occurs, causing permanent damage. This is called a
myocardial infarction (MI) or heart attack.
it is unusual, a heart attack can also be caused by a spasm of a coronary
artery. During coronary spasm, the coronary arteries restrict or spasm on
and off, causing lack of blood supply to the heart muscle (ischemia). It may
occur at rest and can even occur in people without significant coronary
Each coronary artery supplies blood to a
region of heart muscle. The amount of damage to the heart muscle depends on
the size of the area supplied by the blocked artery and the time between
injury and treatment.
Healing of the heart muscle begins soon
after a heart attack and takes about eight weeks. Just like a skin wound,
the heart's wound heals and a scar will form in the damaged area. The new
scar tissue does not contract or pump as well as healthy heart muscle
tissue. So, the heart's pumping ability is lessened. The amount of lost
pumping ability depends on the size and location of the scar.
What are the
symptoms of a heart attack?
Symptoms of a heart attack include:
- discomfort, pressure,
heaviness, or pain in the chest (angina), arm or below the breastbone
- discomfort radiating to
the back, jaw, throat or arm
- a fullness, indigestion
or choking feeling (may feel like heartburn)
- sweating, nausea,
vomiting or dizziness
- extreme weakness,
anxiety or shortness of breath
- rapid or irregular
During a heart attack, symptoms last 30
minutes or longer and are not relieved by rest or oral medications
(medications taken by mouth).
Some people have a heart attack without
having any symptoms (a "silent" myocardial infarction). A silent MI can
occur among all patients, though it is more common among diabetics.
Do not delay
Quick treatment to open the blocked artery is essential to lessen the amount
of damage. At the first signs of a heart attack, call for emergency
treatment . The best time to treat a heart attack is within one to two hours
of the first onset of symptoms. Waiting longer than that increases the
damage to your heart and reduces your chance of survival.
Reasons people delay:
- They are young and
cannot believe it is happening to them.
- Symptoms are not what
- They may deny the
symptoms are serious and wait until they go away.
- They may ask the advice
of others, especially family members.
- They may first try to
treat the symptoms themselves, using aspirin or antacids.
- They may think the
symptoms are related to other health problems (stomach, arthritis).
- They may put the care of
others first (first take care of children or other family members) and not
want to worry them.
Chest discomfort can be described many
ways. It can occur in the chest or in the arms, back or jaw. If you have
symptoms, take notice. These are your heart disease warning symptoms. Treat
all chest discomfort as angina or a heart attack unless your doctor has told
Treatments (medications, open heart surgery
and interventional procedures) do not cure coronary artery disease.
Having had a heart attack or treatment does not mean you will never have
another heart attack; it can happen again.
How is a heart
Once the emergency care team arrives, they will ask you about your symptoms
and begin to evaluate you. The diagnosis of the heart attack is based on
your symptoms, ECG and the results of your blood tests. The goal of
treatment is to treat you quickly and limit heart muscle damage.
The ECG (also known as EKG or electrocardiogram) can help to tell how much
damage has occurred to your heart muscle and where it has occurred. In
addition, your heart rate and rhythm can be watched.
Blood may be drawn to measure levels of biochemical markers (sometimes
called enzymes). These markers are found inside your body's cells and are
needed for their function. When your heart muscle cells are injured, their
contents -- including the markers -- are released into your bloodstream. By
measuring the levels of these markers, the doctor can determine the size of
the heart attack and approximately when the heart attack started. Other
blood tests may also be performed.
Echocardiography can be used during and after a heart attack to learn about
how the heart is pumping and what areas are not pumping normally. The echo
is also valuable to see if any structures of the heart (valves, septum,
etc.) have been injured during the heart attack.
Cardiac catheterization, also called cardiac cath, may be used during the
first hours of a heart attack if medications are not relieving the ischemia
or symptoms. The cardiac cath can be used to directly visualize the blocked
artery and guide the choice for which procedure (such as angioplasty, stent
placement or coronary artery bypass surgery) may follow.
How is a heart
Once your heart attack is diagnosed, your treatment begins immediately --
possibly right in the ambulance or emergency room.
The knowledge gained in past years regarding acute coronary syndromes and
what happens in the artery during a heart attack has helped guide medical
treatment. The goals of medication therapy are to break up or prevent blood
clots, prevent platelets from gathering and sticking to the plaque,
stabilize the plaque and prevent further ischemia.
These medications must be given as soon as
possible (within one to two hours from the start of your heart attack) to
decrease the amount of damage. The longer the delay in starting these drugs,
the more damage that occurs and the less benefit they can provide.
Medications for this purpose may include:
- thrombolytic therapy
- other antiplatelet drugs
- any combination of the
Other drugs, given during or after a heart
attack, lessen your heart's work, improve the functioning of the heart,
widen or dilate your blood vessels, decrease your pain and guard against any
life-threatening heart rhythms.
During or shortly after a heart attack, you may go to the cardiac
catheterization laboratory to directly evaluate the status of your heart,
arteries and the amount of heart damage. In some cases, procedures (such as
angioplasty or stents) are used to open up your narrowed or blocked
arteries. These procedures may be combined with thrombolytic therapy to open
up the narrowed arteries, as well as to break up any clots that are blocking
If necessary, bypass surgery may be
performed to restore the heart muscle's supply of blood.
subsequent heart attacks prevented?
The goal after your heart attack is to keep your heart healthy and
reduce your risks, to prevent future damage to your heart. Take your
medications, change your lifestyle and see you doctor for regular heart
Medications are prescribed after a heart attack to:
- prevent future blood
- lessen the work of your
heart and improve your heart's performance and recovery
- lower cholesterol
Other medications may be prescribed if
needed. These include medications to treat irregular heartbeats, lower blood
pressure, control angina (chest discomfort) and treat heart failure.
It is important to know the names of your
medications, what they are for and how often and at what times to take them.
Your doctor or nurse should review your medications with you. Keep a list of
your medications and bring them to each of your doctor visits. If you have
questions about your medications, ask your doctor or pharmacist.
There is no cure for coronary artery disease. In order to prevent the
progression of this disease, you must follow your doctor's advice and make
necessary lifestyle changes. You can stop smoking, lower your blood
cholesterol, control your diabetes and high blood pressure, follow an
exercise plan, lose weight, and control stress and anger.
See you doctor for
regular heart check-ups
Make a doctor's appointment four to six weeks after you leave the hospital.
Your doctor will want to check the progress of your recovery. Your doctor
may ask you to undergo diagnostic tests (such as exercise or pharmacological
stress tests or cardiac catheterization) at regular intervals. These tests
can help the doctor to diagnose the presence or progression of blockages in
your coronary arteries and to plan treatment.
Call your doctor sooner if you have
symptoms such as chest pain that becomes more frequent, increases in
intensity, lasts longer, or spreads to other areas; shortness of breath,
especially at rest; dizziness. or irregular heartbeats.