What does it mean if a heart echogram (electrocardiogram) shows regurgitation?

Understanding Heart Regurgitation on Echocardiogram

Regurgitation on a heart echogram indicates that blood is flowing backward through a heart valve that should be closed, representing a significant valve dysfunction that can impact cardiac function and patient outcomes.

What Is Valvular Regurgitation?

Valvular regurgitation occurs when heart valves fail to close properly, allowing blood to flow in the reverse direction. This is visualized on echocardiography as abnormal blood flow during parts of the cardiac cycle when the valve should be completely closed.

Types of Regurgitation

• Mitral Regurgitation: Blood flows backward from the left ventricle to the left atrium
• Aortic Regurgitation: Blood flows backward from the aorta into the left ventricle
• Tricuspid Regurgitation: Blood flows backward from the right ventricle to the right atrium
• Pulmonary Regurgitation: Blood flows backward from the pulmonary artery into the right ventricle

Causes of Valvular Regurgitation

Regurgitation can be classified based on its etiology:

• Primary (Structural): Due to abnormalities of the valve itself

  • Degenerative valve disease
  • Rheumatic heart disease
  • Infective endocarditis
  • Congenital valve abnormalities
  • Trauma
  • Flail leaflet or chordal rupture

• Secondary (Functional): Due to abnormalities affecting the valve without directly involving it

  • Left ventricular dysfunction
  • Ventricular dilation
  • Atrial fibrillation (particularly for tricuspid regurgitation)
  • Pulmonary hypertension

Echocardiographic Assessment of Regurgitation

Echocardiography is the primary tool for diagnosing and assessing valvular regurgitation 1:

1. Color Doppler Imaging: Shows the regurgitant jet, though jet area alone is not recommended for quantification of severity 1

2. Vena Contracta Width: Measures the narrowest portion of the regurgitant jet

   • For aortic regurgitation: >6 mm indicates severe regurgitation
   • For mitral regurgitation: >7 mm indicates severe regurgitation 1

3. Proximal Isovelocity Surface Area (PISA) Method: Quantifies regurgitation severity

   • For aortic regurgitation: Effective regurgitant orifice area ≥30 mm² indicates severe regurgitation
   • For mitral regurgitation: Effective regurgitant orifice area ≥40 mm² indicates severe regurgitation 1

4. Continuous Wave Doppler: Assesses the density and shape of the regurgitant jet signal

5. Pulmonary/Hepatic Vein Flow Patterns: Systolic flow reversal in these veins indicates severe regurgitation 1

Clinical Significance and Consequences

The clinical impact of regurgitation depends on:

1. Severity: Mild, moderate, or severe based on quantitative and qualitative parameters

2. Acuity:

   • Acute regurgitation: Sudden onset with normal chamber sizes but potentially life-threatening hemodynamic consequences
   • Chronic regurgitation: Gradual onset with compensatory chamber enlargement 1

3. Chamber Remodeling:

   • Left atrial and ventricular enlargement in mitral regurgitation
   • Left ventricular dilation in aortic regurgitation
   • Right atrial and ventricular dilation in tricuspid regurgitation 1

4. Ventricular Function: Progressive ventricular dysfunction may result from chronic severe regurgitation 1

Clinical Implications

1. Prognostic Significance:

   • Even mild mitral regurgitation in the setting of myocardial infarction is associated with worse prognosis 1
   • Severe tricuspid regurgitation is associated with decreased survival and increased risk of heart failure 2

2. Monitoring Requirements:

   • Regular echocardiographic follow-up is needed to assess progression
   • Progression of regurgitation is associated with increased cardiovascular mortality and hospitalizations 3

3. Treatment Considerations:

   • Medical therapy for underlying conditions
   • Surgical repair or replacement for severe symptomatic regurgitation
   • Transcatheter interventions in selected high-risk patients 4

Important Caveats in Echocardiographic Assessment

1. Technical Limitations:

   • Eccentric jets may be underestimated by color Doppler 1
   • Proper alignment of the Doppler beam is crucial for accurate assessment 1

2. Integrated Approach:

   • Multiple parameters should be used to assess regurgitation severity 1
   • Clinical findings should be correlated with echocardiographic findings 1

3. Hemodynamic Conditions:

   • Positive pressure ventilation and sedation can significantly reduce the severity of regurgitation 1
   • Assessment should be interpreted in the context of the patient's hemodynamic state

4. Imaging Modality Selection:

   • Transthoracic echocardiography (TTE) is the initial imaging modality of choice 5
   • Transesophageal echocardiography (TEE) is indicated when TTE is nondiagnostic or when complications are suspected 5
   • 3D echocardiography provides superior assessment of valve morphology and regurgitant orifice 1

Remember that echocardiographic findings must be interpreted in the clinical context, as discrepancies between symptoms, physical examination findings, and imaging results can occur 1.