Differential Diagnosis

The patient presents with a complex clinical picture, including elevated troponin, atrial fibrillation with rapid ventricular response (RVR), congestive heart failure (CHF) with a moderate right pleural effusion, an occlusive thrombus in the left leg, and significantly elevated BNP and D-dimer levels. Here is a structured approach to the differential diagnosis:

• Single Most Likely Diagnosis

  • Pulmonary Embolism (PE): The combination of atrial fibrillation with RVR, CHF, moderate right pleural effusion, significantly elevated D-dimer, and the presence of an occlusive thrombus in the leg strongly suggests a pulmonary embolism. The elevated troponin and BNP levels further support this diagnosis, indicating right heart strain, a common complication of large PEs.

• Other Likely Diagnoses

  • Acute Coronary Syndrome (ACS): Elevated troponin levels could indicate myocardial infarction, which, combined with atrial fibrillation and CHF, suggests a possible cardiac cause for the patient's presentation. However, the presence of a thrombus in the leg and the high D-dimer level lean more towards a thromboembolic event.
  • Heart Failure Exacerbation: The patient's CHF and elevated BNP could indicate an exacerbation of heart failure, potentially triggered by atrial fibrillation with RVR or a pulmonary embolism.

• Do Not Miss Diagnoses

  • Dissecting Aortic Aneurysm: Although less likely given the information, a dissecting aortic aneurysm could present with chest pain, heart failure, and elevated troponin. It's a critical diagnosis to consider due to its high mortality rate if missed.
  • Cardiac Tamponade: The presence of a moderate pleural effusion and signs of heart failure could, in rare cases, be associated with cardiac tamponade, especially if there's a significant pericardial effusion. This diagnosis is critical to recognize due to its potential for rapid deterioration.

• Rare Diagnoses

  • Thromboembolic Events in Other Locations: While the focus is on pulmonary embolism, it's essential to consider other thromboembolic events, such as paradoxical embolism through a patent foramen ovale, especially given the atrial fibrillation and leg thrombus.
  • Right Ventricular Infarction: This could present with similar signs of right heart failure and elevated troponin but would typically be associated with inferior wall myocardial infarction patterns on the EKG.

Management should focus on stabilizing the patient, anticoagulation for the pulmonary embolism, rate or rhythm control for atrial fibrillation, and addressing the heart failure. The presence of an occlusive thrombus in the leg may require thrombectomy or anticoagulation. Given the complexity and the potential for rapid clinical deterioration, close monitoring in an intensive care setting is advisable.