system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 27-year-old woman comes to the physician because of a 1-month history of progressive shortness of breath. She can no longer walk one block without stopping to catch her breath. Her last menstrual period was 3 months ago. Menarche occurred at the age of 12 years, and menses had occurred at regular 28-day intervals. Cardiac examination shows a grade 3/6, rumbling diastolic murmur at the apex. Laboratory studies show an elevated β-hCG concentration. Which of the following is the most likely explanation for this patient's worsening dyspnea?
assistant
Increased intravascular volume