What is it?

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.

Left ventricular hypertrophy (LVH) 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 the condition. As left ventricular hypertrophy progresses and complications develop, you may experience these left ventricular hypertrophy symptoms:

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

Causes

Left ventricular hypertrophy can happen when one or more things make 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 work of adapting to high blood pressure may result in larger muscle tissue in the walls of the left ventricle. 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). This condition 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. This disease 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.
• Hypertrophic cardiomyopathy. In this disease, the heart muscle (myocardium) becomes abnormally thick — or hypertrophied. This thickened heart muscle can make it harder for the heart to pump blood.
• Athletic training. Intense, prolonged endurance and strength training can cause the heart to adapt so that it can handle the extra workload. In some people, these changes may lead to left ventricular hypertrophy.
• Other medical conditions. Some rare conditions, such as certain types of muscular dystrophy and Fabry's disease, are associated with changes in the heart that increase the risk of left ventricular hypertrophy.

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 workload.
• Obesity can cause high blood pressure and increase your body's demand for oxygen, factors that may lead to left ventricular hypertrophy.

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 (ischaemic heart disease)
• Interruption of blood supply to the heart (heart attack)
• Sudden, unexpected loss of heart function, breathing and consciousness (sudden cardiac arrest)

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. 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 3-D image.

References

http://my.clevelandclinic.org/services/heart/disorders/left-ventricular-hypertrophy-lvh

http://jama.jamanetwork.com/article.aspx?articleid=199812

http://www.mayoclinic.org/diseases-conditions/left-ventricular-hypertrophy/basics/definition/con-20026690

http://www.bloodpressureuk.org/BloodPressureandyou/Yourbody/Enlargedheart