What is the approach to assess for heart failure?

Assessment for Heart Failure

Begin with a focused history and physical examination to identify characteristic symptoms and signs, followed immediately by ECG, chest X-ray, and echocardiography to confirm cardiac dysfunction—a normal ECG makes heart failure highly unlikely. 1

Initial Clinical Evaluation

Key Symptoms to Assess

• Dyspnea patterns: Evaluate exertional breathlessness, orthopnea (inability to lie flat), and paroxysmal nocturnal dyspnea 1
• Bendopnea: Ask if the patient becomes short of breath when bending forward, a specific marker of elevated filling pressures 1
• Fatigue and reduced exercise tolerance: Document specific limitations in activities of daily living 1
• Ankle swelling and weight gain: Recent weight changes >2 kg in 3 days suggest fluid retention 1, 2

Critical caveat: Symptoms alone are unreliable—they correlate poorly with severity of cardiac dysfunction and may be difficult to interpret in elderly patients, women, and obese individuals 1

Physical Examination Findings

The following signs provide the strongest diagnostic value 1, 3, 4:

• Jugular venous distension (JVD): Most specific sign of elevated filling pressures 1, 3
• Hepatojugular reflux: Apply pressure to the right upper quadrant and observe for sustained JVD elevation 3
• Displaced apical impulse: Indicates left ventricular enlargement 4
• Third heart sound (S3 gallop): Highly specific for volume overload 3, 4
• Pulmonary rales/crackles: Suggest pulmonary congestion 1, 3
• Peripheral edema: Bilateral leg swelling, though less specific 1
• Square-wave response to Valsalva maneuver: Indicates elevated filling pressures 1

Assess vital signs systematically: Check orthostatic blood pressure changes, heart rate and rhythm, weight, and BMI at every encounter 1, 5, 3

Essential Diagnostic Testing

First-Line Tests (Perform in All Patients)

12-lead ECG 1, 3:

• A normal ECG has >90% negative predictive value—heart failure is highly unlikely if ECG is completely normal 1
• Look for: prior MI, left ventricular hypertrophy, arrhythmias (especially atrial fibrillation), conduction abnormalities, Q waves

Chest X-ray (PA and lateral views) 1, 5, 3:

• Cardiomegaly (cardiothoracic ratio >0.5)
• Pulmonary venous congestion
• Interstitial edema and Kerley B lines
• Pleural effusions

Two-dimensional echocardiography with Doppler 1, 5, 2, 3:

• This is the definitive diagnostic test—never delay obtaining this study 3
• Measures left ventricular ejection fraction (LVEF) to classify heart failure type:
  • HFrEF: LVEF ≤40%
  • HFmrEF: LVEF 41-49%
  • HFpEF: LVEF ≥50% 1, 2
• Assesses chamber size, wall thickness, regional wall motion abnormalities, and valve function 1, 5, 3

Laboratory Evaluation

Initial blood work 1, 5, 3:

• Complete blood count (anemia can worsen heart failure)
• Comprehensive metabolic panel: electrolytes, BUN, creatinine, glucose
• Liver function tests
• Lipid profile
• Thyroid-stimulating hormone (TSH)
• Urinalysis

BNP or NT-proBNP measurement 1, 5, 3:

• Use when clinical diagnosis is uncertain after initial evaluation 5, 3
• Low-normal levels in untreated patients make heart failure unlikely 1
• Provides prognostic information and helps with risk stratification 1
• NT-proBNP adds the largest quantitative diagnostic contribution beyond history and physical examination (increases diagnostic accuracy by 69%) 4

Important caveat: Natriuretic peptides can be elevated in other conditions including left ventricular hypertrophy, valvular disease, atrial fibrillation, renal dysfunction, and pulmonary embolism 1

Additional Testing in Selected Patients

Coronary artery disease evaluation 5, 3:

• Perform coronary angiography in patients with angina, significant ischemia, or unexplained new-onset heart failure unless contraindications to revascularization exist 1, 3
• Troponin I or T if acute coronary syndrome suspected 3

Specialized testing when indicated 3:

• Hemochromatosis screening (serum ferritin, iron studies)
• HIV testing in at-risk populations
• Rheumatologic panel if systemic disease suspected
• Sleep study if obstructive sleep apnea suspected
• Endomyocardial biopsy in rare cases of suspected infiltrative disease or myocarditis

Diagnostic Algorithm

Step 1: If symptoms (dyspnea, fatigue, edema) are absent, heart failure is unlikely 1

Step 2: If ECG is completely normal, reconsider the diagnosis—heart failure is highly unlikely 1

Step 3: If chest X-ray shows no cardiomegaly or congestion AND ECG is normal, heart failure is very unlikely 1, 6

Step 4: If clinical suspicion remains after Steps 1-3, measure BNP/NT-proBNP—normal levels make heart failure unlikely 1, 4

Step 5: Echocardiography confirms or excludes heart failure and determines LVEF 1

Determining Etiology and Severity

Identify the Underlying Cause

Obtain detailed history for 1, 5, 3:

• Coronary artery disease (most common cause)
• Hypertension
• Valvular heart disease
• Diabetes mellitus
• Alcohol abuse
• Chemotherapy or cardiotoxic drug exposure
• Three-generation family history to identify inherited cardiomyopathy 1

Classify Severity Using NYHA Functional Class 1:

• Class I: No limitation with ordinary activity
• Class II: Slight limitation; comfortable at rest but ordinary activity causes symptoms
• Class III: Marked limitation; less than ordinary activity causes symptoms
• Class IV: Unable to perform any activity without discomfort; symptoms at rest

Identify Advanced Heart Failure

Look for clinical clues suggesting advanced disease 1:

• Persistent symptoms despite optimal medical therapy
• Recurrent hospitalizations
• Progressive decline in functional capacity
• Cardiac cachexia
• Worsening renal function
• Requirement for continuous intravenous inotropes

These patients may need referral to advanced heart failure centers for consideration of mechanical circulatory support or transplantation 1, 2

Common Pitfalls to Avoid

• Do not rely on symptoms alone—they have poor sensitivity and specificity, especially in elderly, obese, and female patients 1
• Do not assume the diagnosis without objective evidence of cardiac dysfunction on echocardiography 1, 3
• Do not skip the ECG—a normal ECG virtually excludes heart failure 1
• Do not forget to search for reversible causes: thyroid disease, anemia, valvular disease, alcohol-induced cardiomyopathy, peripartum cardiomyopathy, viral myocarditis 3
• Do not overlook diastolic heart failure (HFpEF)—it accounts for 40-50% of heart failure cases and has similar mortality to systolic heart failure 7