A 75-year-old man presents with sudden onset dyspnea, chest pain, and fainting. On physical examination, he is hypotensive and has distended neck veins. What is the likely diagnosis, and what are the immediate steps?
This patient's sudden symptoms, along with physical signs of hypotension and distended neck veins, are suggestive of a massive pulmonary embolism, potentially leading to obstructive shock and right heart strain. This is a medical emergency. Immediate steps would include hemodynamic support with fluids and vasopressors as needed, high-flow oxygen, and immediate anticoagulation. Emergent reperfusion therapy, such as systemic thrombolysis or surgical embolectomy, should be considered in consultation with a specialist.