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Dear Friend:
Is your heart in good shape? Are you sure? How do you know? What if you're wrong?
In this special report, I'm going to focus on your heart--not in its spiritual, loving, or caring sense, but its physical sense--its structure, purpose, and a little about its diseases. I'm also going to discuss some common heart tests you've probably heard about, but which few people really understand.
Heart disease is the leading cause of death in America today. While the overall mortality from heart disease is declining, more than 500,000 Americans still die each year, mainly from coronary heart disease, which I'll explain later on.
Other forms of heart disease, like weakening of the heart muscle due to high blood pressure, are also common. Even viruses and bacteria occasionally attack the heart, leading to disability and death. This is probably what happened to Boston Celtics basketball star Reggie Lewis.
Any practicing physician will tell you "there's a lot of heart disease out there." There's also a tremendous amount of confusion and misunderstanding, which produces stress, tension, and worry for many individuals. So in this report, I'm going to try to...
Clear up some of that confusion.
Obviously, I won't clear it all up. But I think you'll learn some important things from this issue that will definitely be of value to you. Heck, they might even save your life! Let's begin by addressing a few key points.
POINT #1: All Sudden Heart Afflictions are Not "Heart Attacks"
People tend to call any sudden heart affliction a "heart attack." Technically speaking,
a heart attack is a very specific event, with a specific underlying cause--blockage of blood flow in a coronary artery (to be described below).
True heart attacks can come on suddenly, although they are usually preceded by warning signs such as chest pain, fatigue, and shortness of breath. But all sudden heart afflictions are not true "heart attacks." For example, acute heart failure--sudden weakening of the heart's pumping ability, say due to an overwhelming infection--can come on very suddenly. But in this case, the coronary arteries may not be involved, so this would not be a true "heart attack."
Misunderstanding this distinction can lead to stress. "My grandparents all died of `heart attacks'" may not mean you are genetically prone to coronary heart disease--the leading killer of Americans over 40. Each grandparent may have died of a different heart disease, none of which may actually be hereditary! Similarly, lack of a family history or complete absence of cardiac symptoms may not always mean you are in the clear.
POINT #2: The Heart Has One Main Function and Four Main Components
The heart is a complex organ. It has many functions we don't yet understand. You can think of your heart, however, as having one main function and four main components. The one main function is to keep blood, oxygen, and other nutrients circulating to the rest of your body.
Without your heart pumping efficiently, you can't get oxygen and nutrients to your brain or other vital organs. You can't get your muscles to perform even minimal activities, like brushing your teeth, combing your hair, or putting on your clothes. And your body would not be able to respond to other increased demands, whether internal or external.
Thus, your heart can be thought of as a wondrous "pumping organ" that automatically varies its output depending upon the needs of your body. To perform this function, your heart has four main structural components, each of which can be subject to disease.
There is also an intake tube (vena cava), an outflow tube (aorta), and a thin membrane that surrounds the heart externally (pericardium), but we won't consider these further.
POINT #3: All Heart Tests Give Us Information About One or More Components
All heart tests give us information about one or more of these four components. Is your heart healthy? It all depends on which components you focus on.
A routine EKG, for example, gives us valuable information about the "electrical system" of your heart. An EKG can tell how fast or slow your heart is beating. It can tell if the electrical system is functioning normally, or if you've previously had a true heart attack (i.e. muscle damage). It can sometimes tell if there are signs of decreased blood flow to healthy muscle tissues. But the EKG tells you little about your heart valves. If you want to know how your valves are doing, you need to turn to other tests (discussed below).
POINT #4: All Heart Tests are Subject To Error!
While modern diagnosis of heart disease is pretty good, no single heart test is 100% reliable! Tests give us some information, but they rarely tell us everything we'd like to know. To make matters worse, all heart tests occasionally give us false information.
We've all heard stories about unfortunate individuals who, after visiting their doctor and having a normal EKG, suddenly dropped dead from a heart attack hours later. There's a reason for this (no, it's not that the doctor was incompetent!). Here it is...
A routine EKG, taken when you are lying still, gives you limited information about the status of your coronary arteries. Remember, it is blockages in these arteries that eventually cause most heart attacks, but...
You can have extensive blockages in your coronary arteries and have a perfectly normal EKG lying down!!!
This also applies to listening to your heart with a stethoscope. This simple test is good for many things. Yet it tells you or your doctor almost nothing about your coronary arteries.
Thus, just having your doctor examine your heart and perform a resting EKG does not tell you that you're heart is completely "fine." Other tests may be needed, depending upon your age and other risk factors.
Understanding Common Heart Tests
Let's now look at some common hearts tests you may have heard about or personally experienced. For each grouping of tests below, I'll start with simple ones, then move on to the more complex. I'll also try to give you a general idea of how much each test costs.
GROUP I--INEXPENSIVE TESTS OF YOUR HEART
There are several inexpensive tests of your heart. Most of these involve going to your family doctor, who can perform these tests and interpret the results without a specialist.
A. History & Physical Examination--a detailed medical history and physical examination, including listening to your heart, lungs, and major arteries with a stethoscope can reveal a wealth of information. Enlargement of the heart, malfunctioning heart valves, irregular heart rhythms, and all sorts of other diseases can sometimes be diagnosed this way. But physical examination can also be inconclusive. A myriad of heart problems--including several that can kill you suddenly--may not show up even if you were examined by the world's best cardiologist.
B. Routine EKG--($25-$50 including interpretation). We've already talked about some of the information gained from this safe, inexpensive test. The important thing to remember about EKG's however, is...
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A NORMAL RESTING EKG TELLS YOU LITTLE ABOUT YOUR CORONARY ARTERIES!
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An abnormal resting EKG means there may be a problem, which is not always serious in nature. But a "completely normal resting EKG" in no way guarantees that your heart is fine or you are immune from suffering a major heart attack. It is still very useful, however, to have this test done every 1-2 years, depending upon your age. If something abnormal does pop up, your life can be saved by finding this out early rather than later.
C. Chest X-ray ($35-$60)--a routine chest xray can tell you about the overall size of your heart, aorta, and other main blood vessels. Sometimes, routine chest xrays pick up heart problems that weren't suspected, but this is rare.
GROUP II--TESTS OF YOUR HEART'S MUSCLE/PUMPING FUNCTION
In addition to physical examination, several sophisticated tests are available to assess the overall pumping efficiency of your heart's muscle chambers.
A. Echocardiogram ($250-$600)--is a painless, risk free test that takes about 30 minutes. A hand-held microphone is placed on your chest and sound waves are recorded as they "bounce back" from your heart, much like sonar on a submarine. The returning echos are captured by a machine which immediately converts them to pictures. With this technology, we can literally "visualize" the internal structures of your heart. We can record how the muscle chambers and valves are functioning, and we can get accurate measurements of heart wall thicknesses.
If a chamber of your heart is not functioning properly, say because it's been damaged by a previous heart attack, or if your heart muscle is abnormally thickened due to years of untreated high blood pressure, we can "see" these abnormalities and measure their severity. Several different types of echocardiograms are currently available. Your doctor can advise you when you might need such a test and which type would be most appropriate.
B. Nuclear Scans ($300-$600)--this test reveals similar information, although somewhat different from echocardiography. The most common nuclear test of muscle function is called a MUGA scan (the letters stand for "multiple gated" heart scan, if you really want to know). A tiny amount of harmless radioactive material is injected through an arm vein and your heart is then "scanned" by a large camera positioned above you as you lie on a table. The injected material mixes with your blood, giving the camera a dynamic view of how well your heart is pumping.
C. Cardiac Catheterization/Angiogram ($1500-$3000)--a more expensive and invasive test, where a thin plastic catheter is inserted into an arm or groin artery and threaded up to the heart. Xray dye is then injected directly into the chambers and coronary arteries. Before echocardiograms and MUGA scans were available, this test was often needed to diagnose major heart muscle or valvular disorders. Today, it's rarely used for these purposes, unless heart surgery is being contemplated. It's more commonly used today to evaluate the status of coronary arteries. But when this test is done for any reason, valuable information about heart valves and muscle function is always obtained.
GROUP III--TESTS OF YOUR HEART VALVES
Most valve problems cause audible murmurs detectable with a stethoscope. A murmur is nothing more than a sound blood makes when it flows in a swirling manner. Normally, no such swirling sounds are heard. But when valves become stiff, narrowed, "floppy," or "leaky," the resulting turbulence of blood flow inside the chambers causes characteristic types of murmurs to arise.
(NOTE: Some heart murmurs are not significant, and many people have these so-called "innocent murmurs" which never cause any problems. Sometimes, however, a person with a soft heart murmur may need to take antibiotics before certain types of surgery or dental procedures to prevent infections on their valves. Your doctor can advise you if this is needed.)
A. Echocardiograms--in addition to physical examination, echocardiograms are excellent for detecting and quantifying valvular abnormalities. A new type of echocardiogram, called a Doppler Flow Study, is sometimes useful in selected situations.
B. Cardiac Catheterization--as mentioned above, this test yields good information about heart valve function. It is not usually performed for this purpose today, because it does involve some risk (small) and since non-invasive tests such as echocardiograms can give similar information.
GROUP IV-TESTS OF YOUR HEART'S ELECTRICAL SYSTEM
A. Routine EKG--a routine EKG, done in your doctor's office, can pick up many major and minor electrical abnormalities. These include extra heart beats, irregular heart rhythms, abnormal conduction patterns, and several types of electrical "heart block." A downside of EKG's, however, is they can only detect an electrical abnormality if it occurs while the test is being done.
Many electrical problems of the heart are intermittent in nature. If you "catch" an episode while the EKG is being recorded, the diagnosis is very simple. But if these abnormalities happen only occasionally, you've got to go to other means.
B. Holter Monitors and Event Recorders--($150-$300). These are portable EKG recorders connected to wires taped to your chest. You wear these around, day and night, for 1-7 days (24 hours being the most common interval). They record every heart beat, usually more than 100,000 per day, and the recording is then analyzed by computer and reviewed by a physician.
C. Electro-Physiological Stimulation--in some instances, advanced electrical tests must be performed by an expert. These tests involve a tiny risk, similar to cardiac catheterization. But in the rare instance when you might need this test, the risk of not doing it is usually far greater.
GROUP V--TESTS OF CORONARY BLOOD FLOW ("AM I GOING TO HAVE A HEART ATTACK?)
When people ask "is my heart healthy?" most often they want to know--"Am I in danger of having a heart attack?" Remember, the absence of symptoms plus a normal physical exam plus a normal resting EKG does not answer this question! The best way to sort this question out is to have some type of stress test.
All "stress tests" do one important thing--they measure your heart's performance not at rest, but under activity or other increased work load. When your heart is forced to work harder, it increases its output. This requires an increase flow of blood, nutrients, and oxygen to the heart muscle via your coronary arteries. If these arteries are partially blocked or diseased, enough blood may get through at rest or with minimal activity to meet the demand. But when the demand is raised higher, signs of inadequate blood flow through your coronary arteries will usually emerge. These signs can be detected and measured in several ways (see below).
There are different types of stress tests available today. Not everyone needs these tests, and sometimes they are performed for other reasons than assessing heart attack risk. Your doctor can advise you about this, and help you decide which test, if any, is best for you.
A. EKG Stress Testing--($150-$350)--this test uses EKG leads taped to your chest to detect signs of decreased coronary blood flow. Your heart's work load is increased by having you walk on a moving treadmill, or by having you do other types of exercise like riding a stationary bicycle. An EKG is recorded during the entire period of exercise (and for several minutes after exercise) and then is examined carefully for signs of decreased coronary flow.
B. Thallium Stress Testing--($800-$1200)--many people who have no heart disease will have abnormal EKG stress tests nonetheless. To sort these people out, we often go to another means of assessing coronary blood flow. The treadmill or bicycle stress test with EKG monitoring is done again, only this time a small amount of the radionucleide Thallium-201 (or similar isotope) is injected by arm vein toward the end of exercise. A nuclear scanning camera then takes a picture of your heart, at rest, which shows how much of the thallium reached all of your heart muscle. If the accumulation of thallium is decreased in a particular area, a blockage in the corresponding coronary artery is assumed to be present. To differentiate a permanent muscle scar (i.e. an area of muscle permanently damaged by a previous heart attack) from an area of living muscle that may be at risk, the scan is repeated several hours later, again at rest, and the two sets of pictures are compared. Usually, this test is only needed if the EKG stress test is unclear or in other specific situations, which your doctor might determine.
C. Echocardiographic Stress Testing--($500-$800)--similar to thallium stress testing, only before and after echocardiograms are used to detect muscle abnormalities that reflect decreased coronary blood flow during exercise.
D. Persantine, Dopamine, And Other Chemical Stimulation Stress Testing--($800-$1200)--for people who cannot physically walk fast on a treadmill or pedal an exercise bicycle, due to arthritis, leg injuries, or other physical limitations, stress testing can still be performed. In this case, we do the test (with EKG and thallium or echo monitoring) while you are lying still on a table. A small quantity of persantine or other suitable chemical is injected into an arm vein. These chemicals increase the heart rate without having you exercise, or they otherwise increase coronary artery circulation. The heart's function is then recorded in exactly the same ways as mentioned above.
E. Cardiac Catheterization--($1500-$3000)--this test, while not a stress test, is often the best test for detecting coronary artery blockages. It is expensive and it does involve a small degree of risk, however. So it is only used in selected situations, such as in emergency interventions, when bypass surgery is being considered, or when information from stress testing is inconclusive.
Whew! That was a lot of tests and information to cover. As you can see, the question "Is my heart healthy?" isn't a simple one to answer.
Your best bet is not to try to answer this question on your own. No matter how much you read, or how much you learn, you can almost always benefit from the wisdom and judgment of an experienced health professional.
If you are a male over 35 (for women, if you have reached menopause or have had your ovaries removed), if you have a family history of coronary heart disease, if you are significantly overweight, if you have high blood pressure, diabetes, or high blood cholesterol, if you smoke cigarettes, or if you work in a very stressful occupation, you should consider having an EKG stress test every 3-5 years, or more often if your condition warrants. You should also work very closely with your doctor to modify these risk factors as best you can.
This is what I do, since I have a strong history of coronary heart disease in my family. If you do have a stress test, remember that an "abnormal" result does not necessarily mean you have heart disease--other tests may be needed to clarify this. But a NORMAL EKG stress test IS very meaningful:
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KEY POINT TO REMEMBER--IF YOU HAVE A NORMAL EKG STRESS TEST, PROVIDED YOU REACHED THE
EXPECTED HEART RATE FOR YOUR AGE, THIS IS VERY GOOD EVIDENCE THAT YOUR HEART, SPECIFICALLY
YOUR CORONARY ARTERIES, IS IN PRETTY GOOD SHAPE.
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Few things are 100%, however. There are reported cases where people have done well on stress tests, yet their coronary arteries were diseased. Also stress testing doesn't rule out other types of heart disease that can be equally serious. But in this day and age, a normal EKG stress test is very reassuring.
Of course, if you are having any symptoms such as chest pains, palpitations, recurrent dizziness, or abnormal shortness of breath with activity, PLEASE DON'T TRY TO DIAGNOSE YOURSELF. Go to your doctor and get yourself checked out professionally.
Well, I hope you enjoyed this special report and that you learned something useful from it.
Wishing you good health, happiness, and much success,
Mort Orman, M.D.
Copyright ©1995-2010 M.C. Orman, MD, FLP.
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