Left ventricular hypertrophy

Left ventricular hypertrophy is enlargement (hypertrophy) of the muscle tissue that makes up the wall of your heart's main pumping chamber (left ventricle).

Left ventricular hypertrophy develops in response to some factor, such as high blood pressure, that requires the left ventricle to work harder. As the workload increases, the walls of the chamber grow thicker, lose elasticity and eventually may fail to pump with as much force as a healthy heart.

If you have left ventricular hypertrophy, you're at increased risk of heart disease, including heart attack, heart failure, irregular heartbeats (arrhythmia) and sudden cardiac arrest.

The incidence of left ventricular hypertrophy (LVH) increases with age and is more common in people who have high blood pressure or other heart problems.

Symptoms

Left ventricular hypertrophy usually develops gradually. You may experience no signs or symptoms, especially during the early stages of development. When signs or symptoms are present, they may include:

• Shortness of breath
• Chest pain
• Sensation of rapid, fluttering or pounding heartbeats (palpitations)
• Dizziness
• Fainting
• Rapid exhaustion with physical activity

Cause

Left ventricular hypertrophy occurs as a result of one or more things making your heart work harder than normal to pump blood to your body. For example, if you have high blood pressure, the muscles of the left ventricle must contract more forcefully than normal in order to counter the effect of the elevated blood pressure.

The effect of the stronger contraction on your heart is similar to the response of other muscles to an increased workload. If you add weight to a dumbbell for arm curls, your biceps become larger. Similarly, the work of adapting to high blood pressure may result in larger muscle tissue in the walls of the left ventricle. Unlike weight training, however, the increased workload on the heart is constant with each heartbeat and with little time for the heart muscles to relax. The increase in muscle mass causes the heart to function poorly.

Factors that can cause your heart to work harder include the following:

• High blood pressure (hypertension) is the most common cause of left ventricular hypertrophy. A blood pressure reading is given in a unit of measure called millimeters of mercury (mm Hg). Hypertension is generally defined as systolic pressure greater than 140 mm Hg and a diastolic pressure greater than 90 mm Hg, or 140/90 mm Hg. Systolic pressure is blood pressure while the heart contracts, and diastolic pressure is blood pressure while the heart rests between beats.
• Aortic valve stenosis is a narrowing of the aortic valve, the flap separating your left ventricle from the aorta, the large blood vessel that delivers oxygen-rich blood to your body. This partial obstruction of blood flow requires the left ventricle to work harder to pump blood into the aorta.
• Aortic valve regurgitation is a condition in which the heart valve separating the left ventricle and the aorta doesn't close properly, resulting in some blood flowing backward into the left ventricle. This condition increases the volume of blood in the left ventricle and requires more force to pump it out.
• Dilated cardiomyopathy is enlargement of the left ventricle and, in some cases, other chambers of the heart. Because the space inside the left ventricle is large, it fills with more blood and requires the muscle to contract more forcefully when pumping the blood out.
• A heart attack usually causes the loss or scarring of muscle tissue. To compensate for this loss, the surviving muscles may need to pump harder.

Risk factors

Risk factors for left ventricular hypertrophy include the following:

• High blood pressure, a blood pressure reading greater than 140/90 mm Hg, is the greatest risk factor.
• Aortic stenosis, narrowing of the main valve through which blood leaves the heart, may increase the left ventricle's work load.
• Obesity can cause high blood pressure and increase your body's demand for oxygen — factors that require the left ventricle to work harder.
• Coronary artery disease is the obstruction of arteries that supply blood to your heart muscle. If your heart muscle isn't receiving enough blood, your heart responds by pumping more forcefully.

When to seek medical advice

If you experience shortness of breath, brief chest pain or other symptoms associated with left ventricular hypertrophy, see your doctor. Call 911 or your local emergency number if you feel chest pain that lasts more than a few minutes or have severe difficulty breathing.

If you have high blood pressure or another condition that increases your risk of left ventricular hypertrophy, talk to your doctor about regular appointments to monitor your heart. Even if you feel well, you need to have your blood pressure checked annually, or more often if you smoke, are overweight or have other conditions that increase the risk of high blood pressure.

Tests and diagnosis

If you have signs and symptoms associated with heart disease — such as shortness of breath, chest pain, palpitations or others — your doctor will examine your heart function and choose the best treatment.

If you have high blood pressure, your doctor may order heart-related tests as a part of the ongoing management of the condition.

For some of the exams, your doctor may refer you to a heart specialist (cardiologist). Screening tests for left ventricular hypertrophy include:

• Electrocardiogram (ECG). An electrocardiogram — also called an ECG or EKG — records electrical signals as they travel through your heart. Your doctor can look for patterns among these signals that indicate abnormal heart function and increased left ventricle muscle tissue.

• Echocardiogram. An echocardiogram uses sound waves to produce live-action images of the heart. This common test enables your doctor to watch your ventricles squeezing and relaxing and valves opening and closing in rhythm with your heartbeat.

  The echocardiogram is a primary tool for diagnosing left ventricular hypertrophy. If you have left ventricular hypertrophy, your doctor will be able to see thickening of muscle tissue in the left ventricle. An echocardiogram can also reveal how much blood is pumped from the heart with each beat and how stiff the heart muscle is. It may also show related heart abnormalities, such as aortic valve stenosis.

• Magnetic resonance imaging (MRI). Magnetic resonance imaging is a technique that uses a magnetic field and radio waves to create images of soft tissues in the body. It can be used to produce a thin cross-sectional "slice" of your heart or a three-dimensional image.

Complications

Left ventricular hypertrophy changes both the structure and function of the chamber:

• The enlarged muscle loses elasticity and stiffens, preventing the chamber from filling properly and leading to increased pressure in the heart.
• The enlarged muscle tissue compresses its own blood vessels (coronary arteries) and may restrict its own supply of blood.
• The overworked muscle weakens.

Complications that can occur as a result of these problems include:

• Inability of your heart to pump enough blood to your body (heart failure)
• Abnormal heart rhythm (arrhythmia)
• Insufficient supply of oxygen to the heart (ischemic heart disease)
• Interruption of blood supply to the heart (heart attack)
• Sudden, unexpected loss of heart function, breathing and consciousness (sudden cardiac arrest)

Treatments and drugs

Treatment for left ventricular hypertrophy focuses on the underlying cause of the condition. Depending on the cause, treatment may involve medication or surgery.

Treating high blood pressure
Treatment for high blood pressure usually includes both medications and lifestyle changes, such as regular exercise; a low-sodium, low-fat diet; and no smoking.

In addition to lowering blood pressure, some high blood pressure drugs may prevent further enlargement of left ventricle muscle tissue and may even result in shrinking of the hypertrophic muscles. Blood pressure drugs that may reverse muscle growth include the following:

• Thiazide diuretics act on your kidneys to help your body eliminate sodium and water, thereby reducing blood volume. Thiazide diuretics are often the first — but not the only — choice in high blood pressure medications.

• Angiotensin-converting enzyme (ACE) inhibitors are a type of drug that widens, or dilates, blood vessels to lower blood pressure, improve blood flow and decrease the workload on the heart. Examples include enalapril (Vasotec), lisinopril (Prinivil, Zestril) and captopril (Capoten).

  ACE inhibitors cause an irritating cough in some people. It may be best to put up with the cough, if you can, to gain the medication's benefits. Discuss this side effect with your doctor. Switching to another ACE inhibitor or an angiotensin II receptor blocker may help.

• Angiotensin II receptor blockers (ARBs), which include losartan (Cozaar) and valsartan (Diovan), have many of the beneficial effects of ACE inhibitors, but they don't cause a persistent cough. They may be an alternative for people who can't tolerate ACE inhibitors.
• Beta blockers slow your heart rate, reduce blood pressure and prevent some of the harmful effects of stress hormones. These drugs include carvedilol (Coreg), metoprolol (Toprol XL) and bisoprolol (Zebeta).
• Calcium channel blockers prevent calcium from entering cells of the heart and blood vessel walls. This lowers blood pressure. These drugs include amlodipine (Norvasc), diltiazem (Cardizem, Dilacor XR), nifedipine (Adalat, Procardia) and verapamil (Calan, Isoptin, Verelan, Covera).

Aortic valve repair or replacement
If left ventricular hypertrophy is caused by aortic valve stenosis, you may have surgery to remove the narrow valve and replace it with either an artificial valve or a tissue valve from a pig, cow or human-cadaver donor. If you have aortic valve regurgitation, the leaky valve may be surgical repaired or replaced.

Prevention

The best way to help prevent left ventricular hypertrophy is to maintain healthy blood pressure. Here are a few tips to better manage your blood pressure:

• Monitor high blood pressure. If you have high blood pressure, get a home blood pressure measuring device and check your blood pressure frequently. Schedule regular checkups with your doctor. The target for healthy blood pressure is less than 120/80 mm Hg.
• Make time for exercise. Regular exercise helps lower blood pressure. Aim for 30 minutes of moderate activity at least five times a week. Talk to your doctor about whether you need to restrict certain physical activities, such as weightlifting, which may temporarily raise your blood pressure.
• Watch your diet. Avoid foods that are high in fat and salt, and increase your consumption of fruits and vegetables. Avoid alcohol and caffeinated beverages, or drink them in moderation.

Source:
http://www.mayoclinic.com/print/left-ventricular-hypertrophy/DS00680/DSECTION=all&METHOD=print