A 24-year-old woman with no cardiac history is referred to your clinic for further evaluation of shortness of breath. She had twins 2 months ago and states that she did fine after delivery. Since then, she has noticed progressive shortness of breath with mild exertion, the need for 3 pillows to sleep at night, as well as increased lower extremity swelling.
On physical examination, her blood pressure is 145/90 mm Hg, a pulse is 95 beats per minute, respiration rate is 20 breaths per minute, and she has an oxygen saturation of 93% on room air. She has evidence of jugular venous distention; normal S1, S2; and an S3 is heard on cardiac examination. She has bibasilar crackles and lower extremity edema.