Did You Know?Athletes, or people who are involved in vigorous exercises on a daily basis, may have enlarged hearts. In fact, it has been reported for some athletes to have a heart with twice the mass of a normal heart! It is still a debate whether or not this change is healthy, because athletes are known to have sudden and unexpected cardiac arrests leading to death!
Our heart is divided into 2 sides - the left side and the right side. The right side of the heart is responsible for pumping the deoxygenated blood to the lungs from where it picks up oxygen. After receiving the oxygen from the lungs, the blood is passed to the left side and is pumped out to the body. When, due to certain causes, the heart is unable to meet the blood supply of the body, and tries to pump out blood beyond its normal capacity, it stresses out. This additional stress can lead to the thickening of the muscular walls of the heart, thereby enlarging it. The dilation of the four chambers of the heart (atria and ventricles) can also lead to an enlarged heart.
Note that an enlarged heart is not a disease in itself. Cardiomegaly, or enlargement of the heart can be a result of an underlying disease that one might be suffering from.
Cardiomegaly, or enlarged heart is usually an outcome of a condition known as cardiomyopathy. There are various ways in which the heart becomes enlarged. Either the muscular walls of the heart get extremely thick and /or stiff, or the ventricles and /or atria get dilated, thereby thinning the muscular wall of the heart. The images below will give you a clear picture of how an enlarged heart causes changes in its chambers and walls.
According to the Merck Manuals, there are 3 main types of cardiomyopathy. These are - Dilated Cardiomyopathy, Hypertrophic Cardiomyopathy, and Restrictive Cardiomyopathy.
The diagram above clearly shows the difference between a normal heart and an enlarged one. In case, the cause of enlargement is dilated cardiomyopathy, the ventricles, or in rare cases, the atria become enlarged. Again, in case of hypertrophic cardiomyopathy, the heart wall enlarges, and becomes thick and stiff. In restrictive cardiomyopathy, the walls of the heart become stiff but may not become thick. All these changes in the anatomy of the heart can cause impaired functioning, leading to damage that can prove to be fatal in the form of sudden cardiac arrests.
A point to be noted is that many times, due to temporary stress, the heart may enlarge for some time, eventually retaining its normal size after the cause is over. Certain lifestyle changes can improve the heart health, thereby reversing the enlargement. However, if the cause is serious in nature, or the heart has been enlarged for a long time, then it may not be possible to reverse the size of the heart to normal, as the changes might turn permanent. Listed below are some of the common causes of cardiomegaly.
High Blood Pressure
One of the most common reasons of enlarged heart is uncontrolled high blood pressure. High blood pressure makes the heart more stressed causing it to push itself harder to supply the blood to the entire body, which can often lead to the thickening and stiffening of the heart muscles.
As discussed earlier, cardiomyopathy is a condition wherein the muscles of the heart become weak leading to thickening, stiffening, and enlargement. This causes impairment in the function and structure of the heart, most often leading to heart failure.
Also known as myocardial infarction, a heart attack occurs when due to a blockage, a part of the heart is unable to receive blood supply. This usually happens due to the formation of blood clots in one of the coronary arteries. A section of the heart is deprived of blood supply, eventually leading to damage and death of the heart muscles of that section. This damage may lead to cardiomegaly.
A condition known as peripartum cardiomyopathy causes enlargement of the heart during the last month of pregnancy. The size of the heart may also increase within the 5 months post delivery. In the United States of America, this condition occurs once in every 1,300 - 4,000 deliveries. Peripartum cardiomyopathy is a form of dilated cardiomyopathy - where the ventricles enlarge due to dilation.
Arrhythmia is another term for irregular heartbeats. There are three types of arrhythmias - tachycardia: when the heartbeats are very fast, bradycardia: when the heartbeats are too slow, and irregular: when the heartbeats are uneven. The heart's ability to pump would vary depending upon the rate at which it beats. The stress on the heart resulting from arrhythmia may cause it to enlarge.
Congenital Heart Defects
Congenital defects in the heart are those present since birth. There are many types of congenital heart defects which may affect the valves, ventricles, septum, etc. The defect in the anatomy of the heart can cause it to work harder to meet the blood supply, thereby resulting in enlargement.
Heart Valve Disease
Our heart contains 4 valves located at the exit of each of the 4 chambers. These valves are responsible for ensuring that the blood flows in one direction to avoid problems including overflow resulting in backward leakage. If there is an impairment in any of the 4 valves, one develops heart valve disease. Because the blood flow is affected, it may cause the heart to enlarge. Conditions like rheumatic fever, heart attack, and heart infections may cause this disease.
Hyperthyroidism and Hypothyroidism
The thyroid hormones are secreted by the thyroid gland present in our throat. Hyperthyroidism is a condition in which this gland secretes excessive amount of thyroid hormone, whereas in case of hypothyroidism, the gland is unable to produce the required amount of the hormone. Thyroid is needed by the body to regulate its metabolism, and to aid proper functioning of the muscles - including the heart muscles. Any disorder in this hormone may cause cardiomegaly.
Coronary Heart Disease
This disease accounts for the maximum number of deaths in the United States. Here, the coronary arteries that are responsible for supplying blood to the heart, become narrow as a result of the accumulation of cholesterol deposits in them. The narrowing of the arteries causes decreased blood supply to the heart, thereby causing it to enlarge due to the extra pressure.
Alcohol and /or Cocaine Abuse
The consumption of alcohol, cocaine, and crack, may cause cardiomegaly. This is because the intake of these substances affects the cardiovascular system of the body, putting one under the risk of problems like arrhythmia and high blood pressure. Both these conditions cause an increase in the size of the heart.
Anemia is a condition in which there is a low count of healthy red blood cells in the body. These cells in the blood are responsible for supplying oxygen to the entire body. If the number of red blood cells are inadequate, it means that there would be a decreased supply of oxygen in the body, as well. The heart needs oxygen to enable smooth functioning. The lack of oxygen would cause it to pump harder. If the condition is left untreated, the size of the heart may increase.
It is a disorder in which the body absorbs excessively high amount of iron, which leads to accumulation of iron in various parts - including the vital organs such as the heart. This disorder can either be genetic or acquired. The buildup of iron in the heart can lead to impaired functioning - including enlargement.
Pulmonary hypertension (PH) is a form of high blood pressure that affects only the pulmonary artery (the artery that connects the heart and lungs). PH may cause the blood vessels of the arteries to thicken and constrict, thereby adding pressure on the heart to force the blood to pass through. This may cause weakness in the ventricles, thereby causing enlargement.
Amyloidosis is a rare disease in which the body ends up absorbing high amount of protein, eventually causing protein buildup in various parts of the body - including the heart. When the heart is affected by this condition, its capacity to pump the blood reduces. This reduction causes inadequate supply to the body, forcing the heart to exert. The outcome may be cardiomegaly.
There are certain rare conditions which may lead to heart enlargement. One of them is a condition known as Fabry's disease, in which excessive deposits of a fatty substance known as globotriaosylceramide (GL-3) is observed in the blood vessels of the body. This is due to the inherited deficiency of an enzyme known as alpha galactosidase A, which helps in breaking down (metabolizing) the GL-3 in the body. Accumulation of GL-3 in the heart may cause stress to the heart leading to cardiomegaly.
Other causes include - kidney diseases which require dialysis, lung diseases, HIV infection, nutritional deficiencies, viral infections, and the consumption of certain medications and supplements. For example, medications that alter the thyroid levels in the body, increase the blood pressure, and reduce the red blood cells in the body may change the size of the heart.
Symptoms do not always occur in case of cardiomegaly. However, at times, there are ways in which your heart signifies that it is overworked. Some of the symptoms are listed as under.
» Abnormal /Irregular heartbeats
» Fatigue /Weakness
» Chest Pain
» Breathing Difficulty
» Swelling in the Legs
» Increase in the Abdominal Girth
It is not necessary for one to experience all these symptoms. Depending upon the cause, the symptoms may either be absent, mild, or severe. If there is anything unusual that you are experiencing, do consult your doctor at the earliest.
Diagnosis of cardiomegaly includes a combination of physical examination, laboratory testing, and imaging tests. After you have discussed your symptoms with the doctor, he or she will examine your heart rate using a stethoscope. If swelling is present, the doctor will examine the area as well. Apart from the physical examination, your doctor may ask you to perform the following tests.
A chest X-ray will give the doctor a clear picture of the increased size of your heart. Once it is confirmed that you have cardiomegaly, the rest of the tests are mostly done to determine the cause of the enlargement.
Through an echocardiogram, your doctor can obtain the important details of the physical changes in your heart. Accurate information regarding the thickness of the heart muscles, the condition of the heart valves, the size of the heart, the efficiency in the pumping function, and the damage in the heart tissues, can be determined through this test. It may also be helpful in highlighting the possible causes for cardiomegaly.
This test is helpful in checking the pattern of your heartbeats, and also in determining if there is any damage to the heart. All these details may help the doctor diagnose the cause of enlargement.
CT Scan and MRI
Both these tests provide detailed scans and images of the heart and help the doctors to determine the cause behind the enlargement.
During a stress test, the functioning of your heart is analyzed by putting your body under physical stress. Our heart tends to beat faster while performing a physical activity. This test is done to reveal problems present in the heart, when it is under physical stress. The rate at which the heart beats, and the blood pressure levels are examined by making the patient walk on a treadmill.
Blood tests may be suggested to determine the presence of certain elements and their levels in the body. One can also check if abnormal levels are the cause behind cardiomegaly. This test may help the doctor to identify the possible underlying cause.
It is a medical procedure which helps in evaluating the defects present in the heart. A small tube known as the catheter is inserted through your arm, neck, or groin, and is passed on to your heart. This procedure can also be used to identify the blockage in the blood vessels, if any.
Biopsy is a procedure through which samples of heart tissues are collected for evaluation, thereby diagnosing the cause of the increased size of the heart. This sample may be collected through the process of cardiac catheterization.
Considering the several conditions that may be associated with cardiomegaly, it is needless to say that the treatment would depend upon the specific cause. The treatment plan may be a combination of oral medications, medical procedures, or even surgical procedures. These are explained as under.
Medications and Drugs -
Diuretics - These help in reducing the amount of water and sodium in the body, thereby lowering the blood pressure.
Beta blockers - They contribute in lowering the blood pressure thereby reducing the stress on the heart.
Angiotensin-converting Enzyme (ACE) inhibitors or Angiotensin Receptor Blockers (ARBs) - Both these medications aid the pumping function of the heart by lowering the blood pressure. Your doctor may recommend the use of either of the two, depending on your health condition.
Anticoagulants - To prevent the clotting of blood in the body and reducing the risk of blockage, which may lead to a heart attack.
Digoxin - To help control the abnormal heartbeats, thereby allowing your heart to pump properly.
Medical and Surgical Procedures -
Implantable Cardioverter-defibrillators (ICDs) - It is a small device that is implanted in the chest, especially in patients with severe cases of arrhythmias. ICDs help in monitoring your heartbeats by delivering electric shocks to control your heart rate.
Biventricular Pacemaker - In a healthy heart, the lower chambers pump together at the same time and are in sync with the upper chambers. However, in case of a heart failure, this synchronization is missing. A biventricular pacemaker is implanted to achieve cardiac resynchronization. It is a device that works with the help of a battery and consists of wires known as leads. These lead are placed in the heart tissue to synchronize the upper and lower chambers.
Heart Valve Surgery - A heart valve surgery is done to fix or replace the faulty valve in the heart. Either an artificial valve is replaced with the original valve, or a tissue valve may be taken from a dead human body, or in some cases, from a pig or a cow, to repair the valve of the heart.
Ventricular Assist Devices (VADs) - A VAD is a mechanical pump operated through a battery, which helps the heart to perform its pumping function properly. This device is implanted in your chest through an open-heart surgery. Most of the time, this device is implanted in patients who are waiting for a heart transplant. Usually there is a waiting period to perform a transplant as the patients are more, and the donors are less.
Coronary Bypass Surgery - This option is used if the cause of cardiomegaly is coronary artery disease. In this surgical procedure, a healthy vein is taken from your wrist, legs, or chest, and is placed around the narrowed or blocked region of the artery. This is to divert the blood flow from the area that is blocked to maintain a healthy blood supply to the heart.
Heart Transplant - In severe cases, where it is impossible to correct the functioning of the heart, a heart transplant may be needed. The enlarged heart is replaced with a healthy one, usually obtained from a donor.
Regular monitoring of blood pressure and cholesterol levels helps in identifying improvement in the heart's condition. A fitness regimen, in sync with a diet plan designed for an enlarged heart, should be religiously followed. Since this disorder is a trigger for sudden cardiac death and spares no age group, it is necessary to keep a check on the functioning of the heart under the supervision of a trusted physician.
Disclaimer: The information provided in this article is solely for educating the reader. It is not intended to be a substitute for the advice of a medical expert.