Cardiac hypertrophy refers to the enlargement of the heart muscle through a variety of factors. Though often related to chronic hypertension, cardiac hypertrophy can sometimes actually be a normal physiological response. In most cases, however, heart muscle enlargement is dangerous to the body and is considered a leading factor in heart function-related deaths.
Most of the time, abnormal heart muscle growth occurs in one of the two bottom chambers of the heart: the left and right ventricle. These areas are responsible for pumping blood; the left ventricle pumps blood to most of the body, while the right primarily services only the lungs. Hypertrophy may occur on either side, though different underlying conditions are related to the development of enlargement in each ventricle.
There are two instances in which cardiac hypertrophy can actually be of benefit to its host. Pregnant women may experience mild cardiac enlargement due to increased cardiac stress. This condition generally reverses after the pregnancy concludes and is rarely considered harmful. Competitive athletes may also develop mild hypertrophy due to high amounts of cardiovascular exercise. Since exercise is associated with lower heart risk overall, hypertrophy developed as a physiological response to exercise is rarely cause for concern.
The most common risk factor for developing cardiac hypertrophy is high blood pressure, also known as hypertension. High blood pressure occurs when blood and blood vessels have to work harder to push blood through the body. This, in turn, means that the heart must work harder to pump the requisite amount of blood at the force needed, which can lead to muscle enlargement. Hypertension plays a larger part in the development of left ventricular hypertrophy, whereas lung diseases such as emphysema are more likely to cause abnormal growth in the right ventricle.
Other risk factors for developing the disease include obesity, muscular dystrophy, and other heart problems, such as cardiomyopathy. It is important to note that some people develop the condition without evidence of other heart problems; since symptoms may be relatively mild, the first sign of the disease may be a heart attack or even death. Hypertrophy is often associated with the sudden death of endurance runners or other athletes, especially in the cases of teenage or young adult athletes who would not normally be considered at risk for heart problems.
Symptoms of cardiac hypertrophy may be difficult to detect at first, and tend to become more apparent over time. They may include shortness of breath, decreased exercise capacity, dizziness or blackouts, and periods of heart palpitations. Those with high blood pressure should be on the lookout for symptoms that may indicate hypertrophy.