| Return to Home Page |
Heart
Attacks: 10 Things You Should Know
There
is an abundance of information about heart attacks - much of it
interesting, some of it less relevant to the daily lives of Harvard Heart
Letter readers. Whether you have coronary artery disease or know someone
who does, here are 10 things you really should know about heart attacks. A
heart attack (myocardial infarction) occurs when a portion of the heart
muscle is deprived of blood and oxygen for too long. The
coronary arteries are the lifeline for heart tissue. These vessels lie on
the surface of the heart and supply the cardiac muscle with blood and
oxygen. Most often, the cause of a heart attack is a blood clot (or
thrombus) that forms on the surface of an atherosclerotic plaque within
one of the heart's coronary arteries. The clot chokes off the flow of
blood, denying some of the heart tissue crucial oxygen and nutrients. As a
result, part of the heart muscle downstream from the blockage dies and
eventually forms a scar. The
extent of that damage varies enormously. In some cases, an artery may
become completely blocked, yet very little heart muscle is lost. This is
most likely due to the adaptive safety net called "collateral
vessels.” Collateral
vessels are small arteries that develop over time to compensate for a
perpetually compromised blood supply. For example, the heart of a person
with worsening atherosclerosis likely has been running on reduced blood
flow for some time. This stimulates the development of these tiny
"alternate" routes that can deliver sufficient blood to the
heart muscle even when the main supply becomes completely cut off. A
single blockage can cause significant damage, however, particularly when
it occurs farther up the artery and if collateral vessels have not
developed. Chest pain is not always the first sign of a heart attack. The symptoms of a heart attack vary widely. Although some patients will clutch their chests in pain – the typical depiction of heart attacks on television and in the movies - symptoms are often far subtler. While some individuals do have chest pain in the early phase of a heart attack, many others report feeling "pressure" or "burning" beneath the breastbone. This sensation may well up and then subside, only to return within minutes or hours. In
certain cases, the signs of a heart attack may not appear in the chest at
all, and may appear as tightness or dullness in the left arm, or a feeling
of numbness and tingling in the fingers of the left hand. Less commonly,
the right arm may be affected. Some people describe the sensation as
prolonged indigestion or tightness in the jaw or shoulder. And as many as
one-third of heart attacks are "silent,” that is, they probably
cause no symptoms or such vague ones that the patient does not seek
medical attention. Often the only clues that such an event ever occurred
are changes that show up later in a routine echocardiogram or
electrocardiogram. The
important thing to remember is that a person who experiences prolonged and
unusual discomfort in the chest, neck, or upper abdomen should seek
immediate medical attention. Don't worry that it might turn out to be
nothing. Have it checked anyway. At the first sign of a possible heart
attack, you also should chew and swallow a single 325-mg aspirin tablet to
help slow the clotting process. Every
second counts.
One of the most important revelations of the past 20 years of
cardiology research and practice is that when someone has a heart attack,
quick action is absolutely crucial. Most heart-attack deaths occur within
the first few hours, and the cause is usually cardiac-rhythm disturbances.
Emergency medical technicians or hospital staff can monitor a patient's
heart rhythm and quickly correct any problems with an electrical
cardioversion device. When a heart-attack victim is under the care of
medical professionals, deaths from cardiac arrhythmias are very unusual.
This is why anyone who might be having a heart attack should immediately
call for an emergency medical team. Do not drive yourself or have a family
member take you to the hospital. Doing so is an invitation for disaster. Every second counts for another reason as well. The primary goal in treating a heart attack is to un-block the artery and restore blood flow to the heart muscle as fast as possible in order to minimize damage to the tissue. When the medical team accomplishes this quickly enough, the heart muscle may sustain little, if any, damage. On the other hand, significant and irreparable harm may occur should treatment be delayed as little as 12 hours. If you suspect that you might be having a heart attack, call for an ambulance right away, even if you're not 100% sure. Be ready
to provide emergency and hospital personnel with a brief and accurate
medical history. Certainly,
a complete medical history is of limited value during a possible heart
attack. Some medical issues of concern to your primary-care doctor - for
example, past tonsillitis or a family history of cancer - will not be
terribly useful to the emergency cardiac care team. However, there are
several key pieces of information you want to be sure to give to the
emergency and hospital staff who treat you. If you have ever had bleeding
problems, strokes, cancer, major surgery, or high blood pressure, it could
influence how doctors treat your heart attack. You
should also be sure to tell medical personnel all of the drugs you take
and whether or not you are allergic to any medications. A particularly
important example is sildenafil or Viagra. Any use of this drug within the
previous 24 hours of a suspected heart attack would prohibit the use of
nitroglycerin - a mainstay treatment during the early phase of a heart
attack. Nitroglycerin combined with recent Viagra use can result in a
rapid and potentially fatal drop in blood pressure. Your physician will
choose the safest medications and treatments for you, but to do so he or
she needs to know some basic information, so be prepared to answer this
rapid series of questions. Within
minutes of your arrival in the emergency room, physicians will make a key
decision as to how to open the artery. For
a heart attack that is only a few hours old, the cardiac care team might
opt to clear the artery with clot-dissolving (thrombolytic) drugs, such as
tissue plasminogen activator (tPA), or by inserting a catheter into the
vessel to break through the blockage. Once blood flow is restored, the
cardiologist might use a catheter to dilate the artery and place a fine
wire-mesh tube (stent) to keep the vessel open. The
catheter method (direct angioplasty) is more effective, but requires that
the hospital have a cardiac catheterization laboratory (which many
community hospitals do not) as well as a team trained and immediately
available to perform the procedure. Which method is preferable under a
given set of circumstances is controversial, but all cardiologists agree
that the artery should be opened as rapidly as possible. The interval
between the time a patient arrives in the emergency room and the time he
or she receives treatment to open the artery is so important that it is
regarded as a measure of a hospital's quality of care. There are
several complications that can occur after the first day, but these are
unusual. When
a heart-attack patient dies shortly after reaching the emergency room,
this is usually because she or he has already lost too much heart muscle.
There is, of course, a very small (but real) risk that other serious
complications might occur during hospitalization, including stroke,
pneumonia, or rupture of the heart muscle. For most individuals, however,
the crisis begins to pass when they reach the hospital and the artery has
been opened. From that point on, the real work is rehabilitation and
secondary prevention. Secondary
prevention begins while you are still in the hospital. Secondary
prevention is the effort taken to prevent a second heart attack (or
complications of the first heart attack). Such measures begin from the
time a cardiac patient is first admitted to the hospital. In addition to
clot busters and the drugs used during catheterization, there are a number
of other medications that will likely be added to the list. There is
compelling evidence that these drugs - aspirin, beta blockers, and
angiotensin-converting enzyme inhibitors (ACE inhibitors) promote healing
of the heart and help fend off future events. Your doctor may start you on any of these drugs (in addition to aspirin) as early as the first day of your heart attack and might adjust the dosages while you are still in the hospital. Patients usually stay on aspirin indefinitely and may remain on these other medications for at least one year, and sometimes longer. Because statins are so effective in helping prevent future heart attacks, it is now recommended that cardiologists attack the cholesterol problem immediately by starting patients on these drugs right away. During your recovery, you will undergo a series of tests to assess your long-term cardiac risk. While no cardiologist and no test result can guarantee that you won't have more heart problems, there are tools to assess the likelihood of future cardiac events. These include exercise tests (often performed at a "submaximal" level early after a heart attack), heart-rhythm monitoring, and imaging tests such as echocardiograms (which can determine the extent of heart-muscle damage). Most patients will undergo these tests while in the hospital and over the weeks or months after discharge. When clot busters are used to open the artery, doctors may recommend an angiogram later to look at the coronary arteries, even if the person is doing fine. These additional evaluations may feel burdensome, but they are important to assess and minimize the risk for future problems - and to help you and your doctor be certain that you are doing all you can to keep that risk as low as possible. The
goal of your healthcare team is to get you back on your feet and back to a
normal lifestyle as quickly as possible. Appropriate
heart-attack care in the 1950s and '60s included prolonged bed rest with
hospital stays of a month or more being common practice. We now know that
this is not only unnecessary, but also counterproductive. An extended
period of inactivity results in deconditioning of the body's muscles
(which makes recovery more arduous) and may set the stage for potentially
dangerous blood clots in the legs. What's more, the isolation that may
accompany being out of one's usual routine can psychologically hinder
recovery. As early as the day after a heart attack, nurses and doctors
will begin getting a patient back on his or her feet. Although a complete
return to normal (including sexual activity and exercise) should await
complete clearance from your cardiologist, expect to resume walking and
other daily activities almost right away. Many people benefit from
referral to a cardiac rehabilitation program. Such programs help with
implementing a safe and effective exercise program and risk-factor
control. Prevention
of future heart attacks is essential. The
best treatment for a heart attack is to prevent it. This is why each issue
of the Harvard Heart Letter is filled with messages about diet, the
dangers of smoking, and the benefits of exercise. These risk-reduction
strategies are equally important, if not more so, for patients who have
already had a heart attack. Many
heart-attack patients recover completely and never have another cardiac
problem. In fact, if the first heart attack causes only minimal damage -
and no additional heart attacks occur - it can be almost as if the person
never even had a heart attack. It's the second or third heart attack that
often causes the heart to fail. For this reason, prevention of future
heart attacks is extremely important. There's never a good time to smoke
or to lead a sedentary lifestyle, but after a first heart attack, the
stakes get much higher. The efforts that you make to protect your heart
now may spare you a second heart attack and its potentially debilitating
effects. reprinted from the Harvard Heart Letter - February, 2000 issue |