Heart Failure

Types of Heart Failure

1. Left-Sided Heart Failure:
   • The left ventricle (the main pumping chamber of the heart) is unable to pump blood efficiently into the body.
   • Systolic heart failure (heart failure with reduced ejection fraction, HFrEF): The heart’s pumping ability is weakened, and the left ventricle cannot contract effectively to pump blood.
   • Diastolic heart failure (heart failure with preserved ejection fraction, HFpEF): The left ventricle becomes stiff and does not fill with enough blood during relaxation, leading to reduced blood flow.
2. Right-Sided Heart Failure:
   • The right ventricle is unable to pump blood effectively into the lungs for oxygenation.
   • Often results from left-sided heart failure, as the increased pressure in the left side of the heart is transmitted to the lungs, causing strain on the right side.
   • Can also be caused by conditions like pulmonary hypertension or lung diseases (e.g., chronic obstructive pulmonary disease, or COPD).
3. Congestive Heart Failure (CHF):
   • Refers to the stage of heart failure where fluid builds up in the lungs, liver, and other parts of the body. “Congestive” refers to fluid congestion due to the heart’s inability to pump blood effectively.
4. Acute vs. Chronic Heart Failure:
   • Acute heart failure: A sudden onset of symptoms, often requiring emergency treatment (e.g., due to a heart attack or severe arrhythmia).
   • Chronic heart failure: A long-term, progressive condition that develops slowly over time.

Causes of Heart Failure

Heart failure is usually the result of a variety of conditions that weaken or damage the heart. The most common causes include:

1. Coronary Artery Disease (CAD): Reduced blood flow to the heart muscle from blocked coronary arteries is the leading cause of heart failure. Over time, this can weaken the heart.
2. High Blood Pressure (Hypertension): Chronic high blood pressure forces the heart to work harder, which can lead to heart muscle thickening or weakening.
3. Heart Attacks: A heart attack (myocardial infarction) can damage part of the heart muscle, impairing its ability to pump effectively.
4. Cardiomyopathy: A disease of the heart muscle itself, which may be caused by genetic factors, viral infections, alcohol abuse, or certain medications.
5. Valvular Heart Disease: Damaged or diseased heart valves can disrupt blood flow and cause heart failure.
6. Arrhythmias: Abnormal heart rhythms, particularly atrial fibrillation, can lead to inefficient heart pumping and heart failure.
7. Diabetes: Uncontrolled diabetes can lead to heart disease and, over time, heart failure.
8. Thyroid Disorders: Both an underactive and overactive thyroid can affect heart function.
9. Congenital Heart Defects: Structural problems with the heart present at birth can contribute to heart failure.
10. Chronic Lung Diseases: Conditions like COPD or pulmonary embolism can strain the heart, especially the right side.

Symptoms of Heart Failure

The symptoms of heart failure are varied and depend on the severity of the condition, the side of the heart affected, and other individual factors. Common symptoms include:

1. Shortness of Breath:
   • Often occurs during physical activity or while lying down (orthopnea).
   • May also cause difficulty breathing at night (paroxysmal nocturnal dyspnea).
2. Fatigue and Weakness:
   • The body does not receive enough oxygenated blood, leading to fatigue and reduced ability to perform everyday activities.
3. Swelling (Edema):
   • Fluid retention can cause swelling in the legs, ankles, feet, and sometimes in the abdomen (ascites).
4. Rapid or Irregular Heartbeats:
   • The heart may beat rapidly or irregularly to try to compensate for reduced pumping efficiency.
5. Cough or Wheezing:
   • Due to fluid accumulation in the lungs (pulmonary congestion).
6. Decreased Exercise Capacity:
   • The person may have trouble keeping up with physical activity or become easily winded.
7. Sudden Weight Gain:
   • A rapid increase in weight due to fluid retention.
8. Reduced Appetite and Nausea:
   • Blood flow to the digestive system may decrease, leading to discomfort, nausea, or a loss of appetite.
9. Confusion or Impaired Thinking:
   • In severe cases, reduced blood flow to the brain can cause confusion or difficulty concentrating.

Diagnosis of Heart Failure

To diagnose heart failure, a doctor will consider medical history, symptoms, physical examination, and diagnostic tests, including:

1. Physical Exam: The doctor will listen for abnormal heart sounds, check for signs of fluid retention, and assess overall health.
2. Echocardiogram: An ultrasound of the heart that shows the size, shape, and function of the heart chambers, as well as how well the heart pumps blood (ejection fraction).
3. Electrocardiogram (ECG): Measures the heart’s electrical activity and can help identify arrhythmias or other heart problems.
4. Blood Tests:
   • B-type natriuretic peptide (BNP): Elevated levels of this hormone suggest heart failure.
   • Kidney function tests and liver function tests: To assess how well these organs are functioning in the context of heart failure.
5. Chest X-ray: Can show signs of fluid accumulation in the lungs or enlargement of the heart.
6. Cardiac MRI or CT scan: Provides detailed images of the heart’s structure and function.

Stages of Heart Failure

The American College of Cardiology (ACC) and the American Heart Association (AHA) have developed a staging system to help guide treatment based on the severity of the condition:

• Stage A: At high risk for heart failure but no symptoms (e.g., people with hypertension, diabetes, or a family history of heart disease).
• Stage B: Structural heart disease but no symptoms (e.g., previous heart attack or abnormal heart valve).
• Stage C: Heart failure with symptoms (e.g., shortness of breath, fatigue, fluid retention).
• Stage D: Advanced heart failure requiring specialized treatment, such as heart transplantation or mechanical circulatory support.

Treatment of Heart Failure

The goal of heart failure treatment is to relieve symptoms, improve quality of life, and prevent further damage to the heart. Treatment strategies include lifestyle changes, medications, and sometimes surgical interventions.

Lifestyle Modifications:

• Dietary Changes: A low-sodium diet is crucial to help reduce fluid buildup. Avoiding excess fluids may also be necessary.
• Exercise: Regular physical activity can strengthen the heart and improve symptoms, although it should be tailored to the patient’s ability.
• Weight Monitoring: Patients should regularly monitor their weight to detect early signs of fluid retention.
• Smoking Cessation and Alcohol Reduction: Avoiding smoking and limiting alcohol can significantly improve heart failure outcomes.

Medications:

Several medications are commonly prescribed to help manage heart failure:

• ACE Inhibitors (e.g., lisinopril): Lower blood pressure and reduce the heart’s workload.
• Angiotensin II Receptor Blockers (ARBs) (e.g., losartan): Used when ACE inhibitors are not tolerated.
• Beta-Blockers (e.g., metoprolol, carvedilol): Slow the heart rate and lower blood pressure.
• Diuretics (e.g., furosemide): Help remove excess fluid from the body, reducing swelling and shortness of breath.
• Aldosterone Antagonists (e.g., spironolactone): Help the body excrete excess sodium and fluid.
• SGLT2 Inhibitors (e.g., dapagliflozin): Used for both diabetes and heart failure to reduce symptoms and hospitalizations.
• Digoxin: Improves heart function and helps regulate the heart rate in certain cases.
• Vasodilators (e.g., nitroglycerin): Relax blood vessels to reduce the workload on the heart.

Device Therapies:

• Implantable Cardioverter Defibrillators (ICDs): A device implanted under the skin to detect and correct life-threatening arrhythmias.
• Cardiac Resynchronization Therapy (CRT): A pacemaker-like device that coordinates the timing of the heart’s contractions to improve its pumping ability.

Surgical Options:

• Heart Transplant: For patients with end-stage heart failure who do not respond to other treatments.
• Ventricular Assist Devices (LVADs): Mechanical pumps used to help the heart pump blood, often used as a bridge to a transplant.

Prevention of Heart Failure

Preventing heart failure involves managing underlying conditions and adopting a heart-healthy lifestyle:

• Controlling high blood pressure
• Managing diabetes and high cholesterol
• Eating a balanced, low-sodium diet
• Exercising regularly
• Avoiding excessive alcohol consumption and smoking