Cardiovascular System

CONGESTIVE HEART FAILURE

Congestive Cardiac failure is a condition associated with heart disorders leading to impairment of the heart to supply sufficient blood to meet the body requirements. Cardiac Failure may be associated with the failure of the right or left ventricle or both. Cardiac failure causes the blood to move through the heart and body at a slower rate, leading to increased pressure in the heart. As a result, the heart is unable to pump enough oxygen and nutrients to meet the body's requirements. The heart chambers thus respond by stretching in order to hold more blood to pump through the body or by becoming more stiff and thickened. Such mechanism helps to keep the blood moving for a short while, but the heart muscle walls tend to weaken with time and then are unable to pump with enough strength.

The direct result of the reduced contractility of the cardiac muscles especially those of the ventricles, cause a decrease in the cardiac output and increase in the blood volume of the heart. This causes the kidneys to often respond by causing the body to retain fluid (water) and sodium, as the systemic blood pressure and the renal blood flow both are reduced. This results into building up of fluid in the arms, legs, ankles, feet, lungs or other organs causing oedema which makes the body congested, hence the name Congestive cardiac failure.

The term congestive heart failure is used for the chronic form of heart failure in which the patient has evidence of congestion of peripheral circulation and of lungs; CHF is the end result of various forms of serious heart diseases.

Etiology

There are many causes of congestive heart failure including:

1. Coronary artery disease leading to heart attacks and heart muscle weakness.

2. Primary heart muscle weakness from viral infections or toxins such as prolonged alcohol exposure.

3. Heart valve disease causing heart muscle weakness due to too much leaking of blood or heart muscle stiffness from a blocked valve, and Hypertension.

4. Rarer causes of heart failure include:

• Viral myocarditis (an infection of the heart muscle).
• Infiltrations of the muscle such as amyloidosis.

• HIV cardiomyopathy (caused by Human Immunodeficiency Virus).

• Connective tissue diseases such as Systemic lupus erythematosus.

• Abuse of drugs such as alcohol.

• Pharmaceutical drugs such as chemotherapeutic agents.

• Arrhythmias.

Pathogenesis

Heart failure may be caused by one of the following factors either singly or in combination.

1. Intrinsic Pump Failure: The most common and most important cause of heart failure is weakening of the ventricular muscle due to disease so that the heart fails to act as an efficient pump.

2. Increased workload on the heart:

Increased mechanical load on the heart results in increased myocardial demand resulting in myocardial failure. Increased load on the heart may be in the form of pressure load or volume load.

Types of Heart Failure

Congestive heart failure (CHF) is generally classified as systolic or diastolic heart failure and becomes progressively more common with increasing age. In addition, patients with risk factors for heart disease are more likely to develop congestive heart failure.

Systolic Heart Failure

This condition occurs when the pumping action of the heart is reduced or weakened. A common clinical measurement is ejection fraction (EF). The ejection fraction is a calculation of how much blood is ejected out of the left ventricle (stroke volume) divided by the maximum volume remaining in the left ventricle at the end of diastole, or when the heart is relaxed after filling with blood.

2. Diastolic heart failure: This condition occurs when the heart can contract normally but is stiff, or less compliant, when it is relaxing and filling with blood. The heart is unable to fill with blood properly, which produces backup into the lungs and heart failure symptoms.

3. Acute heart failure: It is sudden and rapid development of failure following massive myocardial infarction, valve rupture, myocarditis etc. The sudden reduction in cardiac output, hypotension without edema is prominent features.

4. Chronic heart failure: It develops slowly with gradual reduction in cardiac output. It is commonly seen in slowly progressive valvular heart disease, systemic arterial hypertension, chronic obstructive pulmonary diseases etc.

Treatment

Treatment of Congestive Cardiac Failure is focused on improving the symptoms and preventing the progression of the disease. The major and often neglected form of treatment is lifestyle improvement, which includes:

1. Regulation of the salt and fluid intake: As the entire body suffers from congestion due to fluid accumulation and also that sodium leads to increased fluid accumulation in the body tissues, it is often recommended to restrict the sodium and fluid intake during the cardiac failure.

2. Exercise: It is recommended to do any activity which one can sustain for more than just a few minutes while your heart, lungs and muscles work overtime. Such an exercise is known as aerobic exercise