ForewordInformation about a real patient is presented in stages (boldface type) to expert clinicians (Drs Ganame, Whitlock, Velianou, and Natarajan), who respond to the information, sharing their reasoning with the reader (regular type). A discussion by the authors follows. P atient presentation: A 29-year-old woman born in Canada, gravida 3, para 2 at 12 weeks gestation, presented to the cardiac pregnancy clinic with a 1-month history of progressive shortness of breath on exertion and chest discomfort. Her medical history was significant for stenosis of a congenital bicuspid aortic valve for which she underwent surgical aortic valve replacement with a #23 Carpentier-Edwards Perimount Magna ease porcine bioprosthetic valve 5 years earlier at the age of 24. There was a questionable history of rheumatic fever at the age of 21; investigations revealed positive antistreptolysin and Sjögren-specific antibody A titers. She was treated with valproic acid for an irregular tremor thought to be Syndenham chorea. The pathology from her surgery did not reveal any evidence of rheumatic disease.She went on to have 2 successful pregnancies at the age of 26 and 27 years without complications. Her last formal review was 1 year before, during her second pregnancy at 34 weeks gestation. Echocardiography showed mild prosthetic valve aortic stenosis with a peak/mean gradient of 41/27 mm Hg, normal ejection fraction, with increased gradients across the prosthetic valve thought to be secondary to a high-output state. She became pregnant unexpectedly 9 months after her second pregnancy and now had progressive shortness of breath and typical angina on exertion; she was unable to climb 1 flight of stairs or push her baby's stroller without having to stop for prolonged periods. Her medications included aspirin, monthly intramuscular penicillin, and maternal vitamins. On physical examination, her blood pressure was 105/66 mm Hg, heart rate 101 beats/min regular, and normal respiratory rate; oxygen saturation was 98% on room air. She was comfortable and in no acute distress. Jugular venous pressure was 5 cm above the sternal angle with a negative abdominojugular reflex. Carotid pulse was of normal volume and contour, with no audible bruits. There was a midline sternotomy scar and the apical impulse was sustained. Auscultation revealed a normal S1, grade 2 late-peaking systolic ejection murmur best heard at the base with radiation to the carotid base, soft S2, and no S3 or S4. Lungs were clear to auscultation bilaterally. There was no pedal edema, all peripheral pulses were palpable, and the abdomen was soft, nontender. A 12-lead ECG revealed sinus tachycardia, with normal axis, normal intervals, and borderline left ventricular hypertrophy by voltage criteria (Figure 1).Dr Ganame: Dyspnea in pregnancy is a common presentation encountered by family physicians, emergency physicians, general internists, obstetricians, respirologists, and cardiologists. A thorough review should be performed to assess whether the symptoms are part of the normal ...