Differential Diagnosis for Atherosclerosis vs Aortic Stenosis on TTE
When evaluating with Transthoracic Echocardiography (TTE) to differentiate between atherosclerosis and aortic stenosis, several key values and characteristics come into play. The following differential diagnosis is organized into categories to help guide the thought process:
- Single Most Likely Diagnosis
- Aortic Stenosis: This is likely if the TTE shows significant valvular calcification, thickening, and restricted motion of the aortic valve leaflets, along with a high gradient across the valve (>40 mmHg). Aortic stenosis typically presents with symptoms such as chest pain, syncope, and heart failure in advanced cases.
- Other Likely Diagnoses
- Atherosclerosis: If the TTE reveals plaques in the aorta, particularly if they are thick, calcified, or protruding into the lumen, this would suggest atherosclerosis. The presence of aortic dilation or aneurysm formation can also be indicative.
- Combined Aortic Stenosis and Atherosclerosis: It's not uncommon for patients to have both conditions, as atherosclerosis can contribute to the progression of aortic stenosis. TTE findings would include those of aortic stenosis along with aortic plaques or dilation.
- Do Not Miss Diagnoses
- Aortic Dissection: Although less likely, aortic dissection is a critical diagnosis that must not be missed due to its high mortality rate. TTE might show an intimal flap in the aorta, and symptoms can include severe, tearing chest pain.
- Severe Aortic Regurgitation: This condition can sometimes be confused with aortic stenosis or atherosclerosis due to overlapping symptoms. TTE would show significant backflow of blood from the aorta into the left ventricle during diastole.
- Rare Diagnoses
- Subvalvular or Supravalvular Aortic Stenosis: These are congenital conditions that can present with similar symptoms to valvular aortic stenosis but are less common. TTE findings would depend on the location and severity of the obstruction.
- Rheumatic Heart Disease: Although more commonly associated with mitral valve disease, rheumatic heart disease can also affect the aortic valve, leading to stenosis or regurgitation. TTE findings would include valvular abnormalities consistent with rheumatic disease.
Each diagnosis has distinct TTE findings and clinical presentations that can help differentiate between atherosclerosis and aortic stenosis, as well as other potential causes of similar symptoms.