A heart in its weakened state is termed heart failure. Debilitating symptoms arise when the heart can no longer pump blood to tissues adequately. This is referred to as congestive heart failure or CHF. Primarily a disease of the elderly, the Centers for Disease Control (CDC) reports more than 670,000 new cases each year. It has multiple causes and a confusing classification system. However, classification of CHF based on function and structure of the heart helps understand the disease.
Left Ventricular Failure
There are four chambers of the heart. Two atria and two ventricles--one on each side of the heart. The ventricles have the most muscle and therefore add the most strength during contraction. The left ventricle is the strongest of all the chambers. Although there are four connecting chambers, occasionally dysfunction occurs in one of the chambers without initially affecting the others. Left ventricle failure is exactly what implies, impairment of the left ventricle due to damage to the heart that exceeds the left ventricle's ability to compensate. The Merck Manual lists causes of left ventricular impairments as coronary artery disease, high blood pressure, heart valve damage, and defects of the heart.
Right Ventricular Failure
The right ventricle of the heart is the second strongest chamber in the heart. It has a direct connection to the rest of the body. Its deterioration in function leads to swelling in the legs. The most common cause of right ventricular failure is left ventricular failure. Pressure built up from the left ventricle's inability to pump blood forward inefficiently leads to increased blood volume and increased pressure in the lung and right ventricle behind it. Other causes of right ventricular failure include all the causes of left ventricular failure plus a right ventricle blood clot, lung disease, hardened heart valves, lung clot, or heart defects.
Systolic Heart Failure
The heart contracts in a regular beating pattern. When the heart contracts, it pushes blood forward through out the blood vessels in the body. Tissues get necessary oxygen to meet metabolic needs. Interference with contraction prevents the heart's primary objective of meeting energy demands. Left ventricular failure and its causes are the primary reasons for systolic heart failure. Damage from a heart attack is the number one cause of systolic failure.
Diastolic Heart Failure
When the heart contracts, it squeezes all the blood from its chambers. When the heart relaxes, it fills with blood for the next contraction to take place. When there is interference with diastolic or relaxation filling, the heart cannot do its job efficiently. The most common causes of diastolic heart failure are those that cause a resistance to filling. These are those associated with aging, including damage to the heart muscle from scarring, an excessively large heart from years of hypertension and diseases that damages heart muscle fibers, making them stiff.
