Congestive Heart Failure (CHF)

Congestive heart failure (CHF) or simply called heart failure, develops due to cardiac malfunctioning that causes a buildup of fluid inside the tissues and extracellular spaces. The heart fails to pump blood at a rate that is compatible with the requirements of metabolizing tissues. To overcome the gap, the filling pressure, also called diastolic filling pressure, is increased. Heart failure can also exist with normal cardiac function in high-demand conditions. The compensatory mechanisms in such cases that increase the blood flow filling pressures or blood pressure, etc., further deteriorate the cardiac function.

Following are the causes of congestive heart failure:

• Underlying conditions that affect the structure and function of the heart. These include diseases like hypertension, coronary artery disease, diabetes mellitus, valvular heart diseases, infections of the heart valves, etc.
• Any physiologic or pathological mechanism that causes a decrease in the oxygen delivery or puts oxidative stress on cardiac muscles.
• Precipitating factors that worsen the underlying disease and further speed up the progression of heart failures, such as anemia or certain drugs.
• Genetic causes for conditions like cardiomyopathies are very common, resulting in heart failure.

There are various categorizations of heart failure depending upon the clinical symptoms. According to one classification, CHF can be classified into:

• Class I- there is no limitation of physical activity
• Class II- there is a slight limitation of physical activity
• Class III- there is a marked limitation of physical activity
• Class IV- the symptoms of heart failure occur even at rest.

According to another classification, CHF can be divided into:

• Stage A- there is a high risk of heart failure, but it is not evident clinically with no symptoms or structural changes that can be detected
• Stage B- there are structural changes in the heart but no symptoms
• Stage C- structural changes with clinically detectable symptoms
• Stage D- heart failure that requires specialized interventions

Heart failure is a global problem. It is becoming an increasing problem in developed and developing countries where lifestyles are becoming more affluent. People take more processed food and resort to limited physical activity for routine functioning. In the United States, heart failure affects 6.5 million people yearly, aged 20 years or older. It is one of the major causes of hospitalizations in the elderly population. Every year, one in eight deaths in the United States is due to heart failure. Risk factors for congestive heart failure include:

• Previous heart attack
• Hypertension
• Diabetes
• Alcohol use
• Dyslipidemia
• Myopathy
• Coronary artery disease
• Pheochromocytoma
• Sleep disorders
• Substance abuse

Signs and symptoms of congestive heart failure are:

• Shortness of breath on exertion
• Shortness of breath on rest
• Shortness of breath on lying down
• Pulmonary edema
• Chest pain
• Palpitations
• Tachycardia
• Fatigue
• Weakness
• Wheezing
• Visible pulsation of eyes
• Distension of neck veins
• Anorexia
• Weight loss
• Nausea
• Weak and rapid pulse
• Central or peripheral cyanosis
• Pallor
• Ascites
• Increased heart sound (P2) with gallop rhythm

 Diagnosis of congestive heart failure is established by the following tests:

• Complete blood count
• Urine analysis
• Serum electrolytes
• Liver function tests
• Renal function tests
• Fasting blood glucose
• Lipid profile
• Thyroid-stimulating hormone (TSH)
• Natriuretic peptide levels
• Chest radiography
• Electrocardiography (ECG)
• Echocardiography
• Pulse oximetry
• Atrial blood gases
• Nuclear imaging
• Exercise testing

Differential diagnoses of congestive heart failure include:

• Acute kidney injury
• Acute respiratory distress syndrome (ARDS)
• Chronic obstructive pulmonary disorder (COPD)
• Emphysema
• Pneumonia
• Cirrhosis
• Pulmonary edema
•  Respiratory failure
• Myocardial infarction
• Nephrotic syndrome

Treatment of congestive heart failure focuses on:

• Finding the underlying cause of heart failure, preventing the precipitating factors, and treating it to relieve symptoms.
• Oxygen supplementation that might require positive pressure ventilation therapy as well.
• Dietary restriction of salt and continuous monitoring of volume intake and outtake on a daily basis to monitor fluid retention.
• The basic aim of pharmacologic therapy is to provide relief against symptoms such as fluid retention that cause breathlessness and prevent complications such as remodeling of the heart.
• Surgical interventions mostly include revascularization procedures, defibrillation devices, valve replacement surgeries or repair, heart transplantation, and ventricular assist devices.

Medications used to manage congestive heart failure include:

• Diuretics
• ACE inhibitors
• Nitrates
• Beta-blockers
• Aldosterone antagonists
• Digoxin
• Anticoagulants
• Inotropic agents

The prognosis of patients with severe disease (class IV) is generally poor. The mortality rate in hospitalized patients with heart failure is more than 10%. As the complication develop, the mortality rate increases. It increases to 40% with myocardial infarction and around 80% with cardiogenic shock. Similarly, comorbid conditions such as hypertension and diabetes also increase the mortality rate significantly and are associated with poor outcomes.

• Heart failure can be avoided by adopting a healthy lifestyle with a balanced diet and regular physical activity.
• Once it has occurred, the recurrence can be prevented by patient education. They should be educated about the importance of compliance with the prescribed treatment regimen and lifestyle changes such as proper diet.
• Maintain a healthy body weight (within normal BMI range) as obesity predisposes to many cardiac conditions that can ultimately lead to heart failure.
• Smoking, alcohol intake, and use of recreational drugs such as cocaine, heroin, ecstasy, and amphetamines can be damaging for the heart and should be avoided.
• Drugs such as NSAIDs, certain antiarrhythmic drugs, and calcium channel blockers exacerbate heart failure and should be avoided in such patients.
• Stress management through medication, counseling, or yoga should be done, as stress can exacerbate blood pressure and ultimately jeopardize cardiac function.