What is the proper way to diagnose heart failure?

Proper Diagnosis of Heart Failure

The diagnosis of heart failure requires both typical symptoms (dyspnea, fatigue, peripheral edema) AND objective evidence of cardiac dysfunction, usually through echocardiography. 1

Initial Clinical Assessment

• Obtain a thorough history focusing on:

  • Current symptoms: dyspnea, fatigue, peripheral edema, orthopnea, paroxysmal nocturnal dyspnea 2, 1
  • Current and past use of alcohol, illicit drugs, alternative therapies, and chemotherapy drugs 2
  • Patient's ability to perform routine and desired activities of daily living 2
  • Risk factors: hypertension, coronary artery disease, diabetes, obesity, metabolic syndrome, cardiotoxin exposure, family history of cardiomyopathy 2, 3

• Physical examination must include:

  • Assessment of volume status (jugular venous pressure, peripheral edema) 2, 1
  • Orthostatic blood pressure changes 2
  • Weight, height, and body mass index calculation 2
  • Cardiac examination for murmurs, gallops, and displaced point of maximal impulse 1, 4

Essential Diagnostic Tests

• First-line diagnostic tests (all patients with suspected heart failure):

  • 12-lead electrocardiogram (a normal ECG makes heart failure diagnosis unlikely with >90% negative predictive value) 2, 1
  • Chest radiograph (posterior-anterior and lateral) to detect cardiomegaly and pulmonary congestion 2
  • Laboratory evaluation: complete blood count, urinalysis, serum electrolytes (including calcium and magnesium), blood urea nitrogen, serum creatinine, fasting blood glucose, lipid profile, liver function tests, and thyroid-stimulating hormone 2, 3
  • Natriuretic peptides (BNP or NT-proBNP) when clinical diagnosis is uncertain (high negative predictive value) 1, 5

• Echocardiography with Doppler is the cornerstone diagnostic test that:

  • Provides objective evidence of cardiac dysfunction at rest 1
  • Measures left ventricular ejection fraction (LVEF) to distinguish between systolic dysfunction and preserved systolic function 2, 1
  • Assesses left ventricular size, wall thickness, and valve function 2
  • Evaluates diastolic function through Doppler measurements 2, 1
  • Helps determine the etiology of heart failure 2

Additional Testing in Selected Cases

• Coronary arteriography should be performed in patients with:

  • Angina or significant ischemia 2
  • Chest pain of uncertain origin who have no contraindications to revascularization 2
  • Known or suspected coronary artery disease without angina 2

• Exercise testing:

  • Limited value for diagnosis but useful for excluding heart failure 2, 1
  • Helpful for prognostic stratification 2
  • Useful to determine if heart failure is the cause of exercise limitation 1

• Radionuclide ventriculography can be performed to assess LVEF and volumes when echocardiography is technically limited 2, 3

• Specialized tests when clinically indicated:

  • Screening for hemochromatosis, sleep-disordered breathing, or HIV 1
  • Tests for rheumatologic diseases, amyloidosis, or pheochromocytoma 1

Diagnostic Algorithm

1. Evaluate symptoms and signs of heart failure (dyspnea, fatigue, peripheral edema) 1
2. Perform initial tests (ECG, chest X-ray, basic laboratory tests) 2, 1
3. Measure natriuretic peptides if clinical suspicion remains 1
4. Confirm with echocardiography 2, 1
5. Determine if systolic (HFrEF: LVEF <45-50%) or diastolic dysfunction (HFpEF: LVEF ≥45-50%) 1
6. Identify underlying etiology 2, 1
7. Classify severity using NYHA functional classification 1

Common Pitfalls and Caveats

• Heart failure symptoms are often non-specific and can be caused by other conditions like pulmonary disease, anemia, or obesity 1, 5
• There is often poor correlation between symptoms and the severity of cardiac dysfunction 1
• Obesity can limit physical examination findings, quality of cardiac imaging, and may cause falsely low BNP levels 5
• Heart failure should never be the final diagnosis - always identify and document the underlying etiology 2
• A normal maximal exercise test in an untreated patient effectively excludes heart failure 2
• Heart failure diagnosis is highly unlikely in the absence of both dyspnea and an abnormal chest radiograph or electrocardiogram 3