Left ventricular hypertrophy (LVH) is a condition in which the lower-left chamber of the heart (left ventricle) grows abnormally thick. This may happen in response to an underlying condition that causes an abnormal strain on the heart’s main pumping chamber. Most commonly, the underlying condition is high blood pressure, and the resulting LVH can often be controlled or even improved with blood pressure medication (antihypertensives). Other underlying conditions include valvular heart disease and coronary artery disease. The risk of developing LVH increases with age.
Whichever condition is present, treatment focuses on the underlying disease process to prevent or even reverse the thickening and/or enlargement of the left ventricle. Treatment is important because LVH increases the risk of heart failure and sudden cardiac death. The best strategies for preventing LVH are to control blood pressure, weight and blood sugar, especially in people with diabetes. The symptoms of LVH will vary depending on the underlying cause. Since the condition tends to develop slowly, there may be little or no symptoms of LVH.
“Enlarged heart” is a broad term used to describe enlargement seen on a chest x-ray. LVH refers strictly to thickening and an increase in the mass of the heart muscle, and it may or may not be associated with enlargement.
About left ventricular hypertrophy (LVH)
Left ventricular hypertrophy (LVH) is a condition in which the lower-left chamber of the heart (the left ventricle, which is responsible for pumping blood through the aortic artery and out to the body) shows signs of hypertrophy. Hypertrophy means that the chamber is thickened, and its mass has increased. LVH suggests that something is putting an abnormal strain on the muscular left ventricle, forcing it to pump harder than it should. LVH is not a disease. Rather, it is the result of an underlying condition.
Ultimately, the left ventricle gradually shows signs of hypertrophy as it works harder to keep up with the increased demands. Over time, the left ventricle will need more and more blood to nourish the enlarged muscle and will begin to lose some of its ability to relax between contractions. It may also compress cardiac capillaries, thereby reducing blood flow to the heart muscle itself. Without treatment, left ventricular hypertrophy could lead to heart attack, heart failure, arrhythmias and/or sudden cardiac death.
The role of hypertension is particularly important in LVH. Studies have shown that LVH often occurs early in life among patients with hypertension. In some cases, LVH may even precede the development of hypertension leading researchers to suggest there is a genetic component to LVH that predisposes people to developing hypertension.
Risk factors and causes of LVH
Left ventricular hypertrophy (LVH) is the result an underlying condition that causes the heart muscle of the left ventricle to grow and thicken. There are two main causes for LVH, which include:
Systolic overload. In most cases of LVH, the left ventricle is being strained during the systole, the phase of the heartbeat in which the heart contracts to pump blood. Systolic overload tends to result in thickening but very little enlargement of the left ventricle, which is known as predominant LVH. Thickening of the heart muscle is considered a compensatory mechanism in response to excessive work. When this mechanism fails, heart enlargement (dilation) with subsequent heart failure may result. The most common cause of systolic overload is hypertension. Other causes include aortic valve stenosis and congenital anomalies such as coarctation of the aorta.
Diastolic overload. Diastolic overload is a strain on the left ventricle resulting from conditions that overload it with blood during diastole. This is the phase of the heartbeat in which the heart relaxes and takes in oxygen-rich blood, ready for the next contraction. In diastolic overload, the thickening can eventually be associated with progressive enlargement (dilatation) of the left ventricular chamber as it stretched to accommodate the extra blood. Causes of diastolic overload include mitral and aortic valve regurgitation and dilated cardiomyopathy.
An inherited condition, called hypertrophic cardiomyopathy, results in a thickening of both the left and the right ventricles. The condition is due to genetic defects in the enzymes that regulate heart muscle growth and/or metabolism. It may lead to sudden death, heart failure and arrhythmias.
In rare cases, well-trained athletes may experience physiologic hypertrophy. These individuals do not exhibit hypertension or signs of heart failure. It is important to differentiate this condition from other serious conditions that may not show symptoms, such as aortic stenosis or hypertrophic cardiomyopathy. Physiologic hypertrophy usually goes away after a period of physical training is discontinued.
Risk factors for LVH include:
Age. Most of the conditions that cause LVH (e.g., hypertension, valvular disease) increase with age.
Obesity. The larger the body, the harder the heart has to work to pump blood around it. This can lead to LVH. Additionally, obesity increases the risk of other conditions that cause LVH.
Coronary disease. Blockages in the blood vessels that restrict the flow of blood increase the workload of the heart.
Race. Recent studies have shown a grater prevalence of LVH among black Americans. This may be related to the higher instance of hypertension in this population.
Signs and symptoms of LVH
In the absence of a related condition called hypertrophic cardiomyopathy, mild left ventricular hypertrophy (LVH) typically produces no symptoms. In more advanced forms, the condition may begin to progress to heart failure, with symptoms such as:
Shortness of breath (dyspnea). This is one of the earliest symptoms of heart failure. The patient gets winded and fatigued more quickly than before, perhaps just by doing regular daily activities or even lying in bed. There is also decreased tolerance to exercise, and the muscles may feel weaker than before.
Angina, due to the increased demand for oxygen.
Swelling (edema) of the legs is another common symptom in heart failure, though it could also be caused by unrelated conditions.
Swollen neck veins.
Abdominal discomfort such as swelling, pain or nausea.
Mental confusion.
Dizziness or fainting.
Galloping heartbeat (palpitations).
In addition to these symptoms, which the patient may notice, the physician may also be able to detect signs of congestive heart failure, including:
An abnormal heart murmur (a telltale sign of a valve-related disorder).
A crackling sound of fluid in the lungs (rales), which is a sign of pulmonary congestion.
A rapid heartbeat (tachycardia) or other abnormal heart rhythms (arrhythmias).
Kidney malfunction or failure (in the later stages of heart failure).
Swelling and fluid retention (edema) in the liver or gastrointestinal tract (in advanced stages of heart failure).
Diagnosis and treatment of LVH
After a physician has obtained the patient’s full medical history and given the patient a physical examination, several tests may be ordered to diagnose left ventricular hypertrophy (LVH). Typically, physicians use one of the following tests:
Electrocardiogram. This test measures the electrical activity that occurs when the heart contracts. To obtain this information, electrodes are placed on various points on a patient’s body. The electrical activity is recorded on a paper print-out for analysis. LVH produces abnormal electrical activity on an electrocardiogram.
Echocardiogram. This test used sound waves that bounce off the heart to produce moving images on a screen. An echocardiogram can measure the thickness of the heart wall and can detect other conditions that may have caused LVH. An echocardiogram is more sensitive in detecting LVH and can usually confirm a diagnosis and rule out a related condition called hypertrophic cardiomyopathy and valvular abnormalities.
Treatment of LVH depends on the underlying cause of the condition. It can often be controlled or even improved with blood pressure medications (antihypertensives) such as ACE inhibitors, beta blockers, diuretics and calcium channel blockers. Some studies suggest that ACE inhibitors, beta blockers and calcium channel blockers are more effective in reducing the heart’s size than other types of blood pressure medications, such as diuretics.
If hypertension is the cause, physicians may also recommend weight loss and reduced salt intake.
If one or more leaky valves (valvular regurgitation) are present, this condition may also require treatment, such as an aortic valve replacement.
LVH may develop as a result of hypertrophic cardiomyopathy. This genetic condition causes partial or complete thickening of the heart, which can interfere with blood flow. Severe cardiomyopathy may require surgery to remove a portion of the thickened wall.
In all cases, reducing the degree of LVH has been associated with a decreased risk of adverse cardiovascular events, including arrhythmia, congestive heart failure and ischemic heart disease.
Prevention methods for LVH
The main controllable risk factors for left ventricular hypertrophy (LVH) are high blood pressure and being obesity. People with diabetes may also be at increased risk. Therefore, the best ways to reduce the risk of developing LVH are:
Regular checkups at the physician, including blood pressure checks and glucose tests to screen for diabetes.
Careful control of high blood pressure or diabetes (e.g., with antihypertensives or insulin, respectively).
Exercise regularly.
Eat a heart-healthy diet.
Maintain a healthy weight.
It is also important that patients who have aortic stenosis are treated for the condition before it permanently damages the heart.
Athletes who are at risk for physiologic hypertrophy may wish to consult their physician about ways to reduce this risk.
Questions for your doctor
Preparing questions in advance can help patients have meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctors the following questions related to left ventricular hypertrophy (LVH):
Why do you suspect that I have LVH?
If I have LVH, does that mean I have an enlarged heart?
What tests will I receive to diagnose this condition?
How often will I need to have these tests?
What is the likely cause of my LVH?
What are my treatment options?
What are the risks associated with these treatments?
If medications are part of my treatment, which ones will I be prescribed?
How will I know if the medications are working?
What will happen if the medications do not improve my condition?
What lifestyle changes could help me?
Should I limit or modify my exercise program because of LVH?
Can I pass LVH on to my children?
How does LVH differ from hypertrophic cardiomyopathy?
