Differential Diagnosis for a 55-year-old Male with SOB and Enlarged Heart on CXR
Single most likely diagnosis:
- Heart Failure (HF): The severely enlarged heart size, redistribution of pulmonary venous flow, and accentuation of central bronchovascular markings with central reticular interstitial prominence on the CXR, along with an elevated BNP of 3400, strongly suggest heart failure, particularly congestive heart failure (CHF). The clinical presentation of shortness of breath (SOB) further supports this diagnosis.
Other Likely diagnoses:
- Cor Pulmonale: Although less likely given the lack of specific findings suggestive of primary pulmonary disease, cor pulmonale (right-sided heart failure due to pulmonary disease) could be considered, especially if there's a history of pulmonary hypertension or chronic lung disease.
- Cardiomyopathy: The severely enlarged heart could be due to various forms of cardiomyopathy (e.g., dilated cardiomyopathy), which would lead to heart failure symptoms and findings similar to those described.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Pulmonary Embolism (PE): Although the CXR does not show classic findings for PE (e.g., Hampton's hump, Westermark sign), and the clinical presentation and BNP level suggest heart failure, a large or multiple PEs could lead to acute right heart strain and failure, presenting with similar symptoms. Missing this diagnosis could be fatal.
- Acute Aortic Dissection: This is a less common condition but critical to diagnose promptly. The absence of mediastinal widening on the CXR does not rule out aortic dissection entirely, especially if the dissection is limited or the CXR is not sensitive enough to detect it.
Rare diagnoses:
- Constrictive Pericarditis: This condition, characterized by a thickened, fibrotic pericardium that restricts diastolic filling of the heart, could present with heart failure-like symptoms. However, it would typically have specific findings on imaging (e.g., pericardial calcification) and might not fully explain the severely enlarged heart size without other supportive evidence.
- Restrictive Cardiomyopathy: Similar to constrictive pericarditis, restrictive cardiomyopathy could lead to heart failure symptoms but would typically have a different set of findings on echocardiography or cardiac MRI, and the heart size might not be as severely enlarged as described.