Combined Valvular Lesions: Echocardiography and Severity Assessment
Clinical Problem
A combined valvular lesion is not the sum of two isolated diagnoses. In multiple valve lesions, one lesion alters the flow through another valve, chamber pressures, ventricular and atrial sizes, thus changing the diagnostic value of usual echocardiographic signs. This is the focus of the EACVI/ESC 2025 consensus on multimodality imaging in multiple valvular heart diseases.
The practical takeaway for the EchoCG protocol: the severity of each lesion is described separately, but the overall clinical severity is formulated at the level of the entire hemodynamic system. If parameters contradict each other, it is not a reason to choose a 'convenient' indicator, but a signal to seek hemodynamic interaction.
Basic Principle: Hemodynamics First, Then Severity Label
In isolated valvular lesions, it is often possible to rely on a set of quantitative and semi-quantitative signs. In combined lesions, the first question is different: which lesion determines the flow and pressure at the moment? For example, proximal valve stenosis may reduce flow through the distal valve and underestimate the gradient. Significant regurgitation may, on the contrary, increase flow and elevate the gradient through a stenotic valve.
Therefore, the protocol should include not only the degree of each lesion but also an explanation: is normal, reduced, or increased flow expected through the evaluated valve; is there chamber dilation; do Doppler data agree with valve morphology and overload consequences.
Common Mistakes
A typical mistake in combined lesions is assessing stenosis only by gradient. The gradient depends on flow, so in low flow, severe stenosis may appear moderate, and in high flow, moderate stenosis may seem more severe. The second mistake is assessing regurgitation without considering pressure in the receiving chamber and accompanying stenosis. The third is the automatic application of indices validated for isolated lesions to a patient with multiple valve defects.
The EACVI/ESC 2025 consensus suggests treating such situations as a separate diagnostic task: checking the internal consistency of measurements, analyzing the impact of each lesion on neighboring valves, and switching to multimodality imaging if necessary.
Classification of Interactions in EchoCG
| Situation | Hemodynamic Effect | Practical Interpretation Risk | What to Check |
|---|---|---|---|
| Stenosis and regurgitation of one valve | Regurgitation increases total flow through the valve, stenosis creates an obstacle to ejection or filling | The gradient may reflect not only the anatomical severity of stenosis but also increased flow | Leaflet morphology, volume overload, Doppler and chamber size consistency |
| Proximal stenosis and distal stenosis | Proximal obstruction limits flow to the next valve | The gradient through distal stenosis may be underestimated | Signs of low flow, distal valve morphology, consequences of chronic overload |
| Stenosis and significant regurgitation of another valve | Regurgitation alters stroke and direct flow | Stenosis and regurgitation parameters become interdependent | Separation of total and effective direct flow, chamber sizes, pulmonary artery pressure |
| Left-sided lesion and tricuspid regurgitation | Left-sided lesion may increase pulmonary pressure and load on the right heart | Tricuspid regurgitation may be a consequence, not a primary problem | Right ventricle, right atrium, pulmonary pressure, mechanism of tricuspid regurgitation |
| Inconsistent severity parameters | Flow, pressure, and morphology give different signals | Erroneous reclassification of the lesion by one number or image | Repeat measurements, alternative imaging method, invasive assessment if necessary |
Aortic Stenosis Combined with Aortic Regurgitation
In the combination of aortic stenosis and aortic regurgitation, the gradient through the aortic valve may be higher due to increased total flow. This does not always indicate a more severe anatomical stenosis. Conversely, significant left ventricular dysfunction or another lesion limiting filling may reduce flow and mask stenosis severity.
The description should separately indicate the morphology of the aortic valve, the degree of calcification or structural lesion, ejection parameters, size and function of the left ventricle, and signs of volume overload. If Doppler assessment and anatomical picture diverge, the consensus considers CT and CMR as important methods for clarification.
Mitral Combinations: Stenosis, Regurgitation, and Flow
Mitral stenosis alters left ventricular filling and may reduce flow through the aortic valve. Therefore, in simultaneous aortic stenosis, its gradient may be lower than expected. Mitral regurgitation, on the contrary, redistributes stroke volume: the total left ventricular output and effective direct flow into the aorta become different values.
In mitral combinations, it is important not to limit to color Doppler. The regurgitation jet depends on the pressure between the left ventricle and left atrium, atrial compliance, rhythm, and accompanying stenosis. The protocol should explicitly state the mechanism of mitral lesion: degenerative, rheumatic, functional, or mixed, as this affects interpretation and treatment strategy.
Tricuspid Valve: Not a Secondary Finding
In multiple valvular lesions, tricuspid regurgitation often reflects the global load on the right heart. Left-sided lesions can lead to pulmonary hypertension, right ventricular dilation, and secondary tricuspid valve insufficiency. Therefore, it should not be described only as 'accompanying' without analyzing the mechanism.
The assessment should include the size of the right ventricle and right atrium, right ventricular function, leaflet morphology, annular size, degree of venous congestion, and estimated pulmonary artery pressure. If the right heart is already remodeled, even moderately appearing regurgitation can have significant prognostic value in the overall picture of multiple lesions.
When Multimodality Imaging is Needed
EchoCG remains the first-line method, but the EACVI/ESC 2025 consensus emphasizes the role of multimodality assessment. CMR is especially useful when it is necessary to clarify chamber volumes, ventricular function, and quantitatively assess regurgitation in poor acoustic windows or conflicting data. CT helps evaluate valve anatomy, calcification, and plan transcatheter and surgical interventions.
Invasive hemodynamics should not replace quality EchoCG but remains an option in fundamental discrepancies between symptoms, non-invasive measurements, and morphology. This is especially important when the decision on intervention depends on which valve is the leading source of overload.
How to Formulate a Conclusion
A good conclusion for a combined lesion should answer four questions. First: which valves are affected and what is the mechanism of each lesion. Second: what signs indicate the severity of each component. Third: is there a hemodynamic interaction that can overestimate or underestimate individual parameters. Fourth: which lesion is most likely to determine symptoms, chamber remodeling, and risk.
If data are inconsistent, this should be explicitly stated: for example, 'Doppler signs of severity do not fully correspond to morphology and overload consequences; multimodality verification is recommended.' Such a formulation is better than assigning an artificially precise severity degree based on one parameter.
Practical Algorithm for the Ultrasound Physician
- Describe the morphology of each valve and the mechanism of the lesion.
- Assess flow: reduced, preserved, or increased in the context of all lesions.
- Correlate Doppler indices with chamber sizes, ventricular function, and pulmonary circulation pressure.
- Identify parameters that may be distorted by an adjacent lesion.
- Formulate the leading hemodynamic syndrome: pressure, volume, or mixed overload.
- In case of discordance, recommend CMR, CT, or invasive assessment depending on the clinical question.
The main rule: in combined valvular lesions, there is no universal 'one number' that replaces clinical thinking. Severity is determined by the consistent interpretation of anatomy, flow, chamber remodeling, and symptom-hemodynamic context.
Frequently asked questions
Can standard severity criteria for isolated lesions be used?
They can be used as a starting point, but not applied mechanically. In multiple lesions, flow and pressure are altered, so individual criteria may overestimate or underestimate severity.
What is the main method in combined valvular lesions?
Transthoracic and, if necessary, transesophageal EchoCG remain the foundation. CMR, CT, and invasive hemodynamics are used in cases of poor windows, complex anatomy, or inconsistent data.
What to write in the conclusion if parameters contradict each other?
It is necessary to explicitly indicate discordance, the presumed hemodynamic interaction, and the recommended method for clarification. Do not assign severity based on a single parameter.