Heart failure is a medical condition where the heart cannot pump enough blood to meet the body’s demands for oxygen and nutrients. This happens when the heart becomes too weak or stiff to function effectively, struggling to circulate blood throughout the body.
The Heart’s Pumping Action
The heart operates as a two-sided pump, divided by a muscular wall known as the septum, which prevents the mixing of oxygenated and deoxygenated blood. Each side has two chambers: an upper atrium and a lower ventricle.
The right side collects oxygen-poor blood returning from the body and pumps it to the lungs for oxygenation.
The left side receives newly oxygenated blood from the lungs. It then pumps this oxygen-rich blood out to the rest of the body through the aorta. The left ventricle has thicker, more muscular walls compared to the right, enabling it to generate the higher pressure needed to deliver blood throughout the entire body.
Left-Sided Heart Failure
Left-sided heart failure occurs when the left side of the heart loses its ability to pump oxygenated blood efficiently to the body. This can happen if the left ventricle becomes too weak to contract forcefully (systolic heart failure) or too stiff to relax and fill properly with blood (diastolic heart failure).
When the left side fails, blood can back up into the pulmonary veins and ultimately into the lungs, leading to pulmonary congestion. This fluid buildup causes symptoms such as shortness of breath, which can worsen with physical activity or when lying flat. Individuals may also experience a persistent cough, sometimes producing pink or white frothy mucus, and fatigue.
Common causes include coronary artery disease, where plaque buildup narrows the arteries supplying blood to the heart muscle, high blood pressure, and heart valve diseases. A prior heart attack can also damage heart muscle, leading to left-sided heart failure.
Right-Sided Heart Failure
Right-sided heart failure develops when the right side of the heart is too weak to effectively pump deoxygenated blood to the lungs. As a result, blood can back up into the body’s veins. This increased pressure causes fluid to leak out of the blood vessels and accumulate in various tissues.
Symptoms are primarily related to fluid retention throughout the body. Individuals commonly experience swelling (peripheral edema) in their legs, ankles, and feet. Fluid can also accumulate in the abdominal area, leading to abdominal swelling or ascites. Rapid weight gain from fluid retention is another indicator.
Causes often involve conditions that increase the workload on the right ventricle. Chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) or pulmonary hypertension, elevate pressure in the lung arteries, making it harder for the right side to pump blood forward. It frequently develops as a consequence of long-standing left-sided heart failure.
The Connection Between Left and Right Heart Failure
Left-sided heart failure is a common precursor to right-sided heart failure. When the left ventricle struggles to pump blood efficiently to the body, pressure increases in the left atrium and subsequently backs up into the pulmonary circulation. This elevated pressure makes it more difficult for the right ventricle to pump deoxygenated blood into the lungs. Over time, this sustained increased workload can weaken and damage the right side of the heart, eventually leading to its failure. This results in combined, or biventricular, heart failure, where both sides are impaired.
Diagnosis and Treatment Approaches
Diagnosing heart failure involves a comprehensive approach. Healthcare professionals conduct a physical examination, looking for signs such as fluid retention or abnormal heart sounds. Blood tests, including checks for B-type natriuretic peptide (BNP) levels, can indicate heart strain.
Diagnostic tools include an electrocardiogram (ECG) to assess the heart’s electrical activity, a chest X-ray to check for fluid in the lungs or an enlarged heart, and an echocardiogram, which uses sound waves to create images of the heart’s structure and function. These tests help determine the type and severity of heart failure.
Treatment aims to manage symptoms, slow disease progression, and improve quality of life. Lifestyle adjustments are recommended, such as dietary changes to reduce sodium intake and regular appropriate exercise. Medications play a significant role, including diuretics to reduce fluid buildup, ACE inhibitors or ARBs to relax blood vessels and lower blood pressure, and beta-blockers to slow heart rate and improve heart function.