Differential Diagnosis for Mild Intensity Moderate to Large Fixed Inferior Wall Defect
- Single most likely diagnosis
- Chronic myocardial infarction or scar: The presence of a fixed defect in the inferior wall without reversible ischemia on stress imaging suggests a chronic process such as a healed myocardial infarction. The fact that the bowel wall attenuation appears to thicken normally with gated stress imaging and no reversible ischemia is noted supports this diagnosis, as it indicates that the defect is not due to ischemia but rather to a permanent damage.
- Other Likely diagnoses
- Attenuation artifact: Although the question mentions that the bowel wall attenuation appears to thicken normally, it's still possible that the fixed defect is due to an attenuation artifact, especially if the patient has a large body habitus or other factors that could cause beam hardening.
- Myocardial fibrosis: This could be another cause of a fixed defect without reversible ischemia, as fibrotic tissue does not exhibit the same metabolic activity as healthy myocardium.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Cardiac sarcoidosis: Although less common, cardiac sarcoidosis can cause fixed defects on imaging due to granulomatous infiltration and fibrosis. Missing this diagnosis could have significant implications for patient management and prognosis.
- Amyloidosis: Cardiac amyloidosis can also cause fixed defects due to the deposition of amyloid proteins in the myocardium, leading to restrictive cardiomyopathy and potentially severe outcomes if not recognized.
- Rare diagnoses
- Fabry disease: A rare genetic disorder that can cause cardiac involvement, including fixed defects on imaging due to the accumulation of globotriaosylceramide in the myocardium.
- Hemochromatosis: Iron overload can cause cardiac involvement, including fixed defects due to iron deposition in the myocardium, although this is relatively rare.