Review Note

Heart Failure (HF)

• Definition: A condition where the heart is unable to pump enough blood to meet the metabolic needs of the body.

Causes

• Hypertension (leading to HFpEF).
• Coronary artery disease (CAD), myocardial infarction (MI).
• Valvular pathology:
  • Examples: aortic stenosis (AS), aortic regurgitation (AR), pulmonary valve stenosis or regurgitation.
• Arrhythmias (e.g., tachyarrhythmias).
• Cardiomyopathies: Dilated, hypertrophic, restrictive, Takotsubo syndrome, toxins (e.g., alcohol, cocaine).
• Congenital heart disease.
• Infective causes: Myocarditis, HIV, Lyme disease.
• Infiltrative diseases: Sarcoidosis, amyloidosis.
• Storage disorders: Hemochromatosis, glycogen storage diseases.
• Drug-induced: Anthracyclines, trastuzumab.
• Metabolic causes: Endocrine diseases, autoimmune diseases.

Diagnosis

• Signs and symptoms of heart failure depending on the underlying cause.

• Signs of right-sided HF:
  • Jugular venous distention.
  • Peripheral edema.
  • Hepatomegaly.
• Signs of left-sided HF:
  • Exertional dyspnea.
  • Angina.
  • Exercise intolerance.
• Auscultation findings:
• Depending on the cause of HF (e.g., systolic or diastolic murmurs, irregular heart rate).

• Rarely normal (if normal, most likely not HF).
• Arrhythmias: e.g., atrial fibrillation (afib).
• Signs of prior ischemia: e.g., Q-waves.
• Signs of LVH.
• Widened QRS.

• Cardiomegaly (cardiothoracic ratio >0.5).
• Boot-shaped heart.
• Pulmonary congestion & pulmonary effusion (in left-sided HF).

• CBC: To rule out anemia.
• ↑ Pro-BNP or BNP.
• If BNP > 35 pg/mL or NT-proBNP > 125 pg/mL, heart failure is suspected.
  

• Possibly ↓LVEF.
  • Normal LVEF: 50-70%.
  • Decreased LVEF: < 40%.
• Diastolic dysfunction.

Classification (According to LVEF)

• HFpEF: LVEF ≥ 50%.
• HFmrEF: LVEF 40-49%.
• HFrEF: LVEF < 40%.