CHAPTER 6

The Heart and Circulation

We all know that the heart pumps blood to the rest of the body, and without a healthy heart, none of us would survive. In fact, about 50% of the people living in an industrialized society will eventually die from diseases related to the heart and circulation. Most of these conditions are avoidable by eating properly, exercising regularly, stopping smoking, and drinking alcohol only in moderation. But how exactly does a physician examine the heart and know whether or not it is functioning properly?

A complete evaluation of the heart and its function includes taking a detailed history, doing a physical examination, taking a chest x-ray, and doing an electrocardiogram. There are several other tests which could also be done, but these are usually reserved for people with specific symptoms and signs which indicate the possibility of heart disease.

The goal of examining the heart is not only to determine if there is any disease, but to decide whether the problem is in the small vessels which actually supply blood to the muscle of the heart (coronary arteries are like three straws lying on the surface which penetrate the muscular walls of the heart itself) or in the valves (the doors between the rooms or chambers of the heart). Further, one needs to determine whether the problem is on the left or right side of the heart. The left side of the heart pumps blood to most of the body under high pressure (which we measure as blood pressure). The right side of the heart receives blood from all over the body and pumps it to the lungs to be oxygenated before it is returned to the heart. This side operates under low pressure. [Figure 6A] Also, problems could relate to the internal nervous system of the heart which coordinates its pumping action.

1. The History: The following symptoms are generally considered to be important in assessing heart functioning: shortness of breath, swelling of ankles (edema), feeling one's own heart beating fast (palpitations), dizziness or fainting (syncope), and chest pain. These symptoms should be reported whenever they occur.
   
   Some symptoms occur primarily with left-sided heart disease, while others occur predominantly with right-sided heart disease. For example, swelling of the legs and a swollen liver and abdomen usually suggests right-sided heart disease. Shortness of breath and fatigue usually suggest left-sided heart disease.
   
   
2. The Physical Examination: The only special equipment needed for this examination is the stethoscope and a penlight.
   1. Looking (Inspection): The first thing that a physician will do in examining the heart is to observe the patient and look for signs of heart disease. The skin should be carefully examined to look for discoloration (a blueness called cyanosis) which could indicate that the tissues are not receiving enough oxygenated blood. The skin can also show signs of too much cholesterol in the blood (which is dangerous for the heart). For example, some people with high cholesterol will have deposits of cholesterol under their skin which appear as little lumps (or nodules) on the elbows or on the eyelids. Others with abnormally high cholesterol levels may have rings of whitish-yellow cholesterol deposits around the edge of their eyes (this is called arcus senilis and is considered normal in people over the age of 60). The fingernails are examined for rounded nails (called clubbing) which indicate long term (or chronic) lack of oxygen. This can be seen in many smokers with emphysema. The patient should also be observed for swelling of the ankles and for shortness of breath. These signs can be subtle indications of a failing heart where the heart muscle does not work well and so blood and fluid get backed up in the lungs (left heart failure) or in the rest of the body (right heart failure).
      
      The final observation involves the veins of the neck. The veins in the neck drain blood from the brain into the right side of the heart. Since this side of the heart operates under low pressure, these veins are normally collapsed. However, when the right side of the heart gets behind in pumping blood to the lungs, these veins may become full and distended. In fact, this happens for short periods of time to all of us each day. When we strain to lift a heavy object or when the opera singer strains to hit the highest note, the right heart temporarily gets behind and our neck veins pop out. If a patient has a disease which causes the right side of the heart to fail, their neck veins may stick out all the time. In addition, their feet may swell with the extra fluid that the heart is unable to pump. A doctor can estimate how much pressure is in these veins (and the right side of the heart) by observing the popping out of the neck veins in various sitting positions. When sitting upright, those of us with normal hearts would not have distended neck veins; while if we were to lay flat, our neck veins would all be somewhat distended. By sitting a patient up at different angles and seeing how far up the neck the distended veins extend, a doctor can estimate the pressure in the right side of the heart (called jugular venous pressure) and, hence, determine if the right side of the heart is weak. Try sitting at different angles in a recliner chair and see if you can determine at what angle your neck veins first pop out.

   2. Listening (Auscultation): The heart and lungs can be listened to directly with the stethoscope. [Figure 6B] However, before listening to the heart, the doctor should listen to the lungs. When the left side of the heart fails, it is unable to keep up with all the blood coming from the lungs, and so fluid can collect in the lungs. This can cause the lungs not to work efficiently, and the patient may experience shortness of breath. When the doctor listens to the lungs of such a patient, she or he will often hear crackling sounds which indicate too much fluid backed up in the lungs.
      
      

      

      Next, the doctor should listen to the heart and assess the rate, rhythm, and the working sounds of the valves. The function of the heart's four valves can be carefully evaluated by listening to the heart in four different places.
      
      Remember, there are four rooms (chambers) in the heart, two on the right and two on the left. On each side of the heart, there is a door (valve) between the two main chambers and a door at the exit of the chambers. There are no valves at the entrance to either side of the heart. The valves in the right side of the heart are named the tricuspid and the pulmonic valves while those on the left side are named the mitral and the aortic valves. For each valve, there is a place on the chest wall from which it can best be heard. When one listens to the heart, one normally hears two sounds followed by a pause. People have described it thus: "Lub-dupp---Lub-dupp---." These two sounds are the normal heart sounds and doctors call them Sl and S2.
      
      Heart valves can be heard when they slap shut and are generally not heard when they slide open. When we hear "lub," we are actually hearing the closing of the tricuspid and mitral valves (or the doors between the chambers of the heart on the right and left sides), and when we hear the "dupp," we are hearing the aortic and pulmonic valves close (the doors at the exits to the right and left sides of the heart). For the most part, these pairs of valves open and close almost simultaneously. If one of the valves closes early or late, the sounds may become split and doctors talk of hearing a split Sl or split S2.
      
      Extra sounds: the S3 and S4: In addition to hearing "lub" and "dupp," doctors can sometimes hear extra sounds called S3 and S4, which may be abnormal. A S3 sound is very low pitched (heard best with the bell of the stethoscope) and occurs in young adults when there is a fluid overload on either side of the heart. A S4 sound is also very low pitched and occurs when the left or right ventricle is stiff and resistant to the flow to incoming blood.
      
      Murmurs: A murmur is what a doctor hears when the valves of the heart are stuck and do not open or close all the way. There are three causes of murmurs. The first is caused by a leaking valve which allows blood to escape backwards and through it. This process is called regurgitation. The second type of murmur is caused by the damage or scarring of a valve. When this occurs, the valve narrows, and the blood passes through the valve when it is only half open. Thus, the sound of blood rushing through the narrowed opening makes a humming sound. This narrowing is called a stenosis. The third type of murmur is caused by a hole in the wall between two of the heart's chambers. The blood leaking through this opening produces a sound recognizable as a murmur. Physicians are able to determine what kind of murmur a patient has by listening to when in the pumping cycle it occurs, how long it lasts, what its pitch is, whether or not its sound tapers, and, if so, by how much, how loud it is, from which listening position it is loudest, which activities make it louder or softer, and whether or not it radiates and can be heard in other areas. A few murmurs are normal, especially in children who have a lot of blood flowing around very fast in a very small space.
      
      In addition to normal heart sounds and murmurs, there are at least three other sounds which can be heard: the rub, the click, and the snap.
      
      Rub: The heart is surrounded by a sac which is filled with a small amount of fluid enabling it to slide freely as it moves while pumping. In some diseases, this sac may become inflamed or filled with large amounts of fluid. When this happens, the heart does not move freely in its protective sac, and its movement has a scratching sound -- almost like opening velcro -- this sound is called a rub.
      
      Clicks: Clicks are heard in the pumping part of the heart cycle (systole) and can be due to the opening of abnormally stiff aortic and pulmonic valves (which is usually not heard) or due to the closing sound of an abnormal mitral valve.
      
      Snaps: Snaps can be heard in the resting part of the heart cycle (diastole) and are usually due to the opening of an abnormal mitral valve.
      
      Bruit (BROO-EE): Besides listening directly to the heart, a doctor will sometimes listen to the arteries in the neck or the arteries in the abdomen which supply blood to the kidneys. In normal arteries, one would hear nothing. However, if some part of the artery is partially blocked, you can sometimes hear the blood moving past a blockage. This sound is called a bruit.

   3. Feeling (Palpation):
      Pulses: In assessing the left side of the heart, one can feel the pulses as described earlier and determine something about the rate and rhythm of the heart beat. [See Figure 3A] Feeling carefully along the neck to the side of the windpipe (trachea), the carotid pulses are easily detected. Be careful to feel only lightly so as not to irritate or block the vessel, and only feel on one side at a time so as not to block blood flow to the brain. See if you can find your own carotid pulsations. The normal pulse has a brisk upstroke, followed by a rapid downstroke and a pause.
      
      Liver: In addition to feeling the carotid pulses, the doctor palpates the abdomen to see if the liver is enlarged. When the right side of the heart fails, blood gets backed up, and the liver becomes engorged and swollen.
      
      Heart: The heart should also be felt directly to see what can be learned from feeling it as it beats. When the doctor places the palm of his hand on the left side of your chest, she or he is feeling for two things. The first is the point where the heart can be felt to beat with the greatest intensity. This point is called the point of maximum intensity (PMI) and is usually located near the left nipple. (See if you can feel yours while laying down; if not, try lying to the left side). The PMI is normally the size of a quarter. The second thing the doctor feels for is a movement next to the breastbone. Normally, this is not felt, but if the right side of the heart is abnormally large, it can be felt to push up or "heave" against the breastbone (sternum) during the heartbeat.
      
      The doctor can use the tips of her or his fingers to feel the pulses in the neck, elbow, wrist, groin, behind the knee, and the feet. This assures that blood is reaching all of the extremities. A doctor may also attempt to feel the largest artery, the aorta, as it passes down through the abdominal area. In relatively thin people, this can usually be felt. Sometimes, the examiner can also estimate the size of this artery. When it is thought to be larger than 4 cm, further investigation is needed to assure that the artery is not abnormally ballooned out or dilated. Such an abnormally dilated aorta is called an aneurysm, and if large enough, it is in danger of bursting or rupturing.

   4. Tapping (Percussion): Tapping is rarely used to assess the size of the heart. By tapping with the middle finger of the right hand on the middle finger of the left hand as it rests on the chest wall, a physician can hear different sounds depending on what is below the chest wall at that point. By tapping from the left side of the chest toward the middle, the doctor can get a crude estimate of the heart's size. Today, however, most doctors use a chest x-ray for this purpose since it is much more accurate.

3. Additional tests: An electrocardiogram (EKG) and a chest x-ray are sometimes used to complete the heart examination. Again, this is usually only necessary when symptoms or findings on the physical examination warrant further investigation.
   
   Chest x-ray: This is a picture of the soft tissues and bony structures of the chest which enables measurement of the size of the heart. Occasionally, an enlarged chamber can also be seen on the x-ray.
   
   EKG: Essentially, an EKG is an electrical picture of the heart. It shows what electrical impulses are generated and transmitted during the pumping cycle of the heart. It is excellent for determining the various complicated rhythms of the heart, but it is also useful in determining if any chambers of the heart are enlarged or if any of the heart muscle is dying from lack of oxygen because the small vessels which supply blood to the heart itself are blocked (as happens in a heart attack).
   
   The Echocardiogram: The echocardiogram is just an ultrasound picture of the heart (visualization through sound waves). Echocardiograms are good for seeing exactly what is wrong with a diseased heart valve, how big the chambers are, how thick the heart muscle is, and for determining the pumping efficiency of the heart.
   
   Arteriogram: An arteriogram is an x-ray dye study of the heart. The arteriogram gives an exact map of the arteries around the heart. These arteries supply blood to the muscle of the heart, and blockages in these arteries are the main cause of heart attacks. With the help of the arteriogram, the doctor can tell exactly where blockages are and plan various treatments, which may include surgery. The doctor can also determine how the valves are working with this study. Regurgitation of blood through valves and holes in the heart wall may cause the heart to fail because it is having to pump too large a volume of fluid. Any amount of blood that escapes backward through a valve must be pumped through again (twice), and this is very inefficient and overworks the heart from a volume standpoint. Blood passing through a narrowed valve, on the other hand, overworks the heart in a different way. To pump blood through a narrowed valve, the heart must generate greater pressures, which causes the heart to be overworked from a pressure standpoint.

Chapter 7