The first and by far the most common cause of an enlarged heart is high blood pressure.  Everyone knows that if you "pump iron" your arms and your legs get stronger and the muscles get bigger.  This is looked upon as a sign of health and being robust.  But in a case of the heart, it is a sign of disease.  Just as a muscle gets bigger when a person lifts weights, the heart gets bigger and thicker when it has to pump against high blood pressure for a prolonged period of time.  Nobody "pumps iron 24 hours a day".  But a poor heart that has to pump against high blood pressure 24 hours a day, eventually begins to wear out.  If a muscle in your arm or your leg gets bigger and stronger, it grows more blood vessels to carry more blood to that muscle.  Unfortunately, this is not true for the heart.  As the heart gets bigger and thicker, it must supply more muscle mass with the same amount of blood that it started off with before high blood pressure occurred.  Thus the amount of blood for the amount of muscle decreases.  This makes the heart less efficient and irritable.  Thus the individual with a thickened heart has less stamina and energy than if the blood pressure is controlled.  Fortunately, there are now medications that can reverse the thickening of the heart that comes from prolonged high blood pressure.  This improves the function of the heart and improves longevity in addition.

     One additional point to make in regards to high blood pressure induced enlargement of the heart is that the heart becomes irritable.  Premature heart beats that feel like extra strong heart beats often occur in this setting.  After a prolonged period of time such as several years, the extra heartbeats can degenerate into what is called ventricular fibrillation.  This is probably the most common cause of sudden death in our society.   It is most commonly associated with high blood pressure.

     The second kind of enlargement of the heart relates to what occurs when the heart finally wears out.  Normally. the heart fills up with about one half glass of blood for each heart beat.  It pumps out a little bit more than half of his blood with each heartbeat.  Thus a little less than half of the blood that was in the heart to begin with is still there after the heart finishes its beat.  The amount of blood pumped out of the heart with each heart beat is called the ejection fraction and is normally around 65% of the blood that was in the heart prior to the heartbeat.  If a heart weakens, the muscle can't contract as well as it normally would.  This results in more blood left in the heart after a heartbeat.  Some people with very severely damaged hearts will only pump out 20% of the blood present in the heart prior to the heartbeat.  These individuals have what is called severe congestive heart failure.  Their hearts are simply too weak to provide the body's needs.  Normally a heart at rest pumps about 5 quarts of blood per minute.  Under extreme need, a normal heart can pump 15-20 quarts of blood per minute when a person is running a race or playing a vigorous athletic game.  People with bad heart failure can maybe pump 3-4 quarts of blood per minute and they have no reserve to increase the heartbeat when stressed.  The individuals with this problem have a severe compromise on what their activities can be and they have a shortened life span as a group.

     The great American way that South Dakotans know and understand says, "pick up the slack and get that heart working harder."  For many years time, doctors tried to find medications that would make a failing heart stronger so it could pump more blood.  Uniformly every endeavor that used this strategy resulted in an increased mortality for the treated group with no real benefit.

     But several years ago instead of trying to make the heart work harder, some very smart doctors decided to give the heart less work to do.  By this strategy, the person's blood pressure is lowered substantially so the heart doesn't have to pump against so much pressure.  It has been found that hearts can recover and regain some strength when this strategy is utilized and there are many medications now that help achieve this.

     The last type of heart enlargement to talk about is called hypertrophic cardiomyopathy.  To break these words down, the prefix "hyper" means increased.  The word "trophic" has to do with growth.  Thus "hypertrophic" means increased or abnormal growth.  The prefix "cardio-" refers to the heart.  That middle part as "-myo-" has to do with heart muscle.  Lastly, the word "-pathy" means disease.  Thus hypertrophic cardiomyopathy means a heart muscle that has gotten diseased because it grew too much.  This is a hereditary condition that is passed to half of the children from the parent who has it.  It is characterized by the heart muscle growing too thick so that the cavity inside of the heart is crowded out.  Normally, the heart should hold a half a glass of blood  before a heartbeat.  In a patient with hypertrophic cardiomyopathy, this is down to much less than that.  In addition, the ability of the heart to empty is compromised because the muscle around the top of the heart where blood goes out becomes too thick and obstructs the flow of blood out of the heart.

     This condition is associated with an increased incidence of sudden unexpected death especially in young athletes.  While it is relatively easy to diagnose if it is thought of, patients usually do not have any symptoms with this condition and thus they don't go to the doctor to be checked.  These are usually healthy, robust individuals.  The markers for a problem include a history of sudden death in young members of the family, increasing fatigue, and irregularity of the heartbeat.  These signs coupled with an increased pulse rate can provide a clinical suspicion to look for individuals with hypertrophic cardiomyopathy before disaster strikes.

     Other than being a compliment for a generous, kind individual, having a big heart is not a good thing at all.  It is relatively easy to diagnose and treat through your local clinics where primary care begins.  Physical examinations to screen for problems at age 30-40 are highly recommended to pick these problems up before they become a tragedy.