Which of the following is a sign of high risk/massive PE?

• A. Tachycardia without hypotension
• B. Sustained hypotension (SBP < 90 or drop > 40 mmHg for > 15 min)
• C. Mild hypoxia
• D. Chest pain with normal BP

Answer: (B)

Massive or high-risk PE is defined by hemodynamic instability from a large embolus. The sign that best fits this category is sustained hypotension, because a large clot obstructs enough of the pulmonary circulation to cause acute right‑ventricular failure and a drop in systemic cardiac output. The threshold—systolic blood pressure less than 90 mmHg or a drop of 40 mmHg or more for more than 15 minutes, not due to another cause—captures this dangerous state. While tachycardia, mild hypoxia, or chest pain with normal blood pressure can occur with PE, they do not by themselves indicate a massive, life‑threatening situation. Recognizing sustained hypotension signals the need for urgent, potentially life‑saving interventions such as systemic thrombolysis if not contraindicated.