Differential Diagnosis for a Pregnant Patient with Shortness of Breath, Racing Heart, and Feeling Faint

Single Most Likely Diagnosis

• Pulmonary Embolism (PE): This condition is a leading cause of maternal mortality and is more common in pregnancy due to increased blood clotting. The symptoms of shortness of breath, racing heart, and feeling faint are classic for PE, making it the top diagnosis to rule out first.

Other Likely Diagnoses

• Anxiety or Panic Attack: Pregnancy can exacerbate anxiety, and symptoms such as shortness of breath, racing heart, and feeling faint can be present. However, these symptoms can also be indicative of more serious conditions, so a thorough evaluation is necessary.
• Pregnancy-Induced Hypertension or Preeclampsia: While these conditions primarily present with hypertension and proteinuria, severe cases can lead to cardiovascular instability, which might manifest as shortness of breath, tachycardia, and dizziness.
• Cardiac Conditions (e.g., Peripartum Cardiomyopathy): Pre-existing or pregnancy-induced cardiac issues can cause these symptoms due to decreased cardiac output or arrhythmias.

Do Not Miss Diagnoses

• Aortic Dissection: Although rare, this is a catastrophic condition that can present with sudden onset of shortness of breath and tachycardia, among other symptoms. It is more common in pregnancy due to hormonal changes affecting the aortic wall.
• Amniotic Fluid Embolism (AFE): AFE is a rare but highly lethal condition that can occur during pregnancy, labor, or postpartum. Symptoms can include sudden shortness of breath, hypotension, and cardiac arrest.
• Placenta Previa or Abruption: These conditions can lead to significant maternal hemorrhage, which might present with symptoms of shock, including tachycardia and feeling faint.

Rare Diagnoses

• Thyroid Storm: A rare but life-threatening complication of untreated or undertreated hyperthyroidism, which can present with tachycardia, shortness of breath, and potentially altered mental status.
• Mitral Stenosis: A pre-existing heart condition that can worsen during pregnancy due to increased blood volume, leading to symptoms such as shortness of breath and palpitations.

Each of these diagnoses requires careful consideration and immediate evaluation to ensure the health and safety of both the mother and the fetus. The key is to quickly identify and manage life-threatening conditions while also considering the unique aspects of pregnancy that can influence symptom presentation and disease severity.