Differential Diagnosis
- Single most likely diagnosis
- D) Tetralogy of Fallot: This condition is characterized by four main features: ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta. The patient's presentation with cyanosis, a harsh systolic ejection murmur, and decreased oxygen saturation, especially with agitation, is consistent with Tetralogy of Fallot. The decrease in murmur intensity with decreased oxygen saturation (during crying) is also a classic finding, as increased right-to-left shunting occurs during episodes of distress, reducing the flow across the pulmonary valve and thus the intensity of the murmur.
- Other Likely diagnoses
- C) Pulmonary stenosis: While pulmonary stenosis can present with a systolic ejection murmur and decreased oxygen saturation, the presence of significant cyanosis and the specific response to agitation (decrease in murmur intensity and significant drop in oxygen saturation) makes Tetralogy of Fallot more likely. However, pulmonary stenosis could be considered, especially if it were severe enough to cause significant right-to-left shunting through a patent foramen ovale or other defect.
- E) Ventricular septal defect: A large ventricular septal defect could potentially lead to heart failure symptoms and a murmur. However, the presence of cyanosis and the specific clinical findings during agitation point more towards a diagnosis like Tetralogy of Fallot, which includes a ventricular septal defect but also other critical components.
- Do Not Miss diagnoses
- B) Coarctation of the aorta: Although less likely given the clinical presentation, coarctation of the aorta can lead to heart failure and potentially to differential cyanosis (lower extremities more cyanotic than upper). It's crucial to consider this diagnosis due to its implications for treatment and prognosis, even though the primary presentation here doesn't strongly suggest it.
- Rare diagnoses
- A) Atrial septal defect: Typically, atrial septal defects present with less severe symptoms and often without cyanosis unless they are part of a more complex defect or lead to significant pulmonary hypertension. The clinical presentation here does not strongly support an isolated atrial septal defect as the primary diagnosis. Other rare diagnoses might include complex congenital heart diseases or unique presentations of more common conditions, but these would be less likely given the information provided.