Diagnosing Heart Failure
The diagnosis of heart failure requires objective evidence of cardiac dysfunction at rest, with echocardiography being the preferred method for confirmation. 1
Initial Diagnostic Steps
- Assess for typical symptoms and signs of heart failure, including fatigue, dyspnea, and peripheral edema, though these are not necessarily specific 2, 1
- Perform an electrocardiogram (ECG), which has >90% negative predictive value to exclude LV systolic dysfunction (a normal ECG makes heart failure highly unlikely) 2, 1
- Order a chest X-ray to detect cardiomegaly and pulmonary congestion 2, 1
- Measure natriuretic peptide levels (BNP/NT-proBNP), which have high negative predictive value and can rule out heart failure when normal 1
- Conduct echocardiography to confirm cardiac dysfunction and determine left ventricular ejection fraction (LVEF), which is essential for distinguishing between systolic dysfunction and preserved systolic function 2, 1
Additional Diagnostic Testing
- Complete blood count, serum electrolytes, blood glucose, liver function tests, blood urea nitrogen, creatinine, lipid panel, urinalysis, and thyroid-stimulating hormone level 3
- Pulmonary function tests to exclude respiratory causes of breathlessness 2
- Consider additional non-invasive imaging in patients with coronary artery disease 2:
- Stress echocardiography
- Nuclear cardiology
- Cardiac magnetic resonance imaging (CMR)
Invasive Testing
- Invasive investigation is generally not required to establish heart failure but may be important for determining cause in individual patients 2
- Coronary angiography should be considered in patients with acute or acutely decompensated chronic heart failure, especially if angina is present 2, 4
- Hemodynamic monitoring should be considered in patients with severe heart failure not responding to initial treatment 2
Common Pitfalls in Diagnosis
- Relying solely on symptoms without objective evidence of cardiac dysfunction 2
- Failing to recognize heart failure with preserved ejection fraction (HFpEF), which accounts for up to 40-50% of heart failure cases 4
- Overlooking heart failure in obese patients, where physical examination findings may be less obvious and BNP levels may be falsely low 5
- Not considering alternative causes of symptoms such as pulmonary disease, anemia, or thyroid disorders 3
Treatment Algorithm After Diagnosis
First-line medications for heart failure with reduced ejection fraction (HFrEF):
- ACE inhibitors for patients with reduced left ventricular systolic function 2, 6
- Beta-blockers for all stable patients with mild to severe heart failure (NYHA class II-IV) with reduced ejection fraction 2, 6
- Diuretics for symptomatic treatment of fluid overload, always in combination with ACE inhibitors when possible 2, 6
Second-line and add-on medications:
- Mineralocorticoid receptor antagonists (spironolactone) for advanced heart failure (NYHA III-IV) 2, 7
- Angiotensin receptor blockers (ARBs) for patients who cannot tolerate ACE inhibitors 2, 7
- Sacubitril/valsartan as a replacement for ACE inhibitors in patients who remain symptomatic despite optimal treatment 7
Device therapy considerations:
- Implantable cardioverter defibrillators (ICDs) for patients with symptomatic HF (NYHA Class II-III) and LVEF ≤35% despite optimal medical therapy 7
- Cardiac resynchronization therapy (CRT) for symptomatic heart failure patients in sinus rhythm with QRS duration ≥150 msec, LBBB QRS morphology, and LVEF ≤35% 7
Non-pharmacological measures:
- Patient education about heart failure, symptom recognition, and self-management 1, 7
- Daily physical activity in stable patients to prevent muscle deconditioning 1, 7
- Control of sodium intake when necessary, especially in patients with severe heart failure 1, 7
- Avoidance of excessive fluid intake in severe heart failure 1, 7
By following this diagnostic approach and treatment algorithm, clinicians can effectively identify heart failure and initiate appropriate therapy to reduce morbidity and mortality in affected patients.