What is the interpretation and management of an abnormal echocardiogram result?

Interpretation and Management of Abnormal Echocardiogram Results

Echocardiography must always be interpreted in the context of a meticulous history and physical examination, as discordance between clinical findings and echo results often indicates either technical error or misinterpretation that requires further investigation. 1

Core Principle: Clinical-Echocardiographic Concordance

The proper interpretation of an echocardiogram should be an essential competency of all cardiologists, requiring direct review of actual images rather than relying solely on text reports or numerical values. 1 The physical examination establishes the "pre-test probability" of disease, to which echocardiographic findings must be applied. 1

Critical Caveats When Interpreting Abnormal Results

When clinical examination suggests severe disease but echocardiography shows mild findings (or vice versa), further evaluation with additional imaging or cardiac catheterization is mandatory. 1 Common discordances include:

• Aortic stenosis appearing mild on echo (gradient <40 mmHg, AVA >1.0 cm²) despite severe clinical findings: This indicates underestimation due to poor Doppler alignment or low-flow states requiring further investigation 1

• Mitral regurgitation with eccentric jets: These systematically underestimate severity; a large E-wave velocity indicates significant disease despite small jet area 1

• Normal left ventricular size with reported severe chronic mitral regurgitation: This combination is physiologically impossible—severe chronic MR must produce LV dilation 1

• Late systolic murmurs with large calculated regurgitant orifice areas: PISA method overestimates severity when regurgitation occurs only in late systole 1

Systematic Approach to Abnormal Findings

Step 1: Verify Technical Adequacy

Review the standardized report for study adequacy, including specific limitations in visualizing prosthetic devices or cardiac structures. 1 Key elements include:

• Overall image quality and acoustic windows 1
• Adequacy of multiaspect imaging 1
• Ability to fully visualize all relevant structures 1
• Comparison to prior studies (essential for temporal evolution assessment) 1

Step 2: Correlate with Clinical Presentation

Match echocardiographic findings with specific clinical indicators: 1

• For chest pain: Echo is Class I indicated when clinical evidence suggests valvular or pericardial disease; Class II for known/suspected coronary disease 1

• For heart murmurs: Determine if the murmur is organic (requires echo in symptomatic patients) versus innocent (Class III indication in asymptomatic patients without other cardiac concerns) 1

• For syncope: Echo is Class I indicated when clinical evaluation suggests structural heart disease or arrhythmias with hemodynamic compromise 1

• For peripheral emboli: Echo is Class I indicated regardless of clinical findings, as the heart is the likely source for large emboli 1

Step 3: Assess Specific Abnormalities

Valvular Disease

For any valvular abnormality, the echo must define: 1

1. The primary lesion and its severity 1
2. Coexisting abnormalities 1
3. Secondary lesions resulting from the primary pathology 1
4. Overall cardiac function 1
5. Reference point for future serial observations 1

Echocardiography has replaced cardiac catheterization as the definitive study for most valvular and congenital heart disease, allowing surgery without catheterization when coronary status is not a concern. 1

Ventricular Function Abnormalities

Regional wall motion abnormalities indicate: 1

• Previous myocardial infarction (known or silent) 1
• Hibernating myocardium from chronic ischemia 1
• Cardiomyopathy, contusion, or other disorders 1

Critical limitation: Extensive coronary artery disease can exist with completely normal resting echocardiography if no ventricular malfunction has occurred. 1 Stress echocardiography (exercise, pharmacologic, or pacing) is required to unmask ischemia-induced wall motion abnormalities not present at rest. 1

Global systolic function assessment includes: 1

• M-mode measurements (fractional shortening, mitral-septal separation) 1
• Two-dimensional measurements (fractional area change, ejection fraction) 1
• Doppler measurements (peak aortic flow velocity/acceleration) 1
• Combined indexes (cardiac output, stroke volume) 1

Hypertrophic Cardiomyopathy

For HCM diagnosis and management, comprehensive 2D echocardiography determines: 1

• Hypertrophy pattern and maximal wall thickness 1
• Presence of LV apical aneurysms 1
• LV systolic and diastolic function 1
• Mitral valve function 1
• Presence and severity of LVOT obstruction 1

If resting gradient is <50 mmHg, provocative maneuvers (sustained Valsalva, squat-to-stand) are essential to uncover LVOT obstruction, as up to 50% of obstructive physiology is missed on resting echo alone. 1

Step 4: Recognize False-Negative and False-Positive Scenarios

False-negative interpretations occur when: 1

• Vegetations are very small or technically difficult to visualize 1
• Multiple mechanical prosthetic valves limit imaging 1
• Abscesses are in early stages (appear hyperechoic) 1
• Severe mitral annular calcification obscures abscesses 1

Repeat echocardiography should be performed in patients with high clinical likelihood of infection despite negative initial high-quality imaging. 1

False-positive interpretations result from: 1

• Noninfectious thrombi, fibrin strands, pannus, or prominent sutures mimicking vegetations 1
• Annular edema or hematoma early post-valve replacement resembling abscess 1
• Fibrous sheaths or thrombus on CIED leads mistaken for infection 1

Imaging results must be placed in context of clinical probability of disease to avoid these errors. 1

Management Algorithm Based on Findings

When Echo Shows Structural Abnormalities

For cardiogenic shock: 2

• Normal LV/RV systolic function, normal chamber dimensions, no significant valvular pathology, and no pericardial effusion virtually rule out cardiac cause of shock 2
• Echocardiography provides immediate impression of etiology and potential treatment line 2

For acute chest pain/dyspnea: 3, 4

• Echo is essential for diagnosing acute coronary syndrome through regional wall motion abnormalities 3
• Rules out alternative etiologies including aortic dissection and pericardial effusion 3, 4
• Allows immediate diagnosis of pericardial effusion/tamponade, evaluation of contractility/volume status, and detection of RV strain from pulmonary embolus 4

When Additional Imaging Is Required

Transesophageal echocardiography is reasonable when: 1

• TTE is inconclusive for clinical decision-making regarding medical therapy 1
• Planning for myectomy or assessing feasibility of alcohol septal ablation 1
• Excluding subaortic membrane or MR from structural mitral valve abnormalities 1

Cardiac CT and/or FDG PET/CT are necessary when: 1

• Moderate or greater clinical likelihood of prosthetic valve/CIED infection with negative echo 1
• Many device portions are not accessible by echocardiography 1
• Multi-modality approach is required for complete evaluation 1

Serial Monitoring Strategy

For established cardiac disease: 1

• Asymptomatic patients: TTE every 1-2 years to assess changes in function, wall thickness, chamber size, LVOT obstruction, and valvular disease 1
• Interval may be extended in clinically stable patients after multiple evaluations 1
• New or worsening symptoms: Immediate TTE to assess hemodynamic progression or new cardiovascular abnormalities 1

Echocardiography should not replace the cardiovascular examination but serves as an accurate, painless method for serial observation. 1