What is the differential diagnosis for a 14-week pregnant patient presenting with chest pain and palpitations?

Differential Diagnosis for Chest Pain and Palpitations at 14 Weeks Gestation

The differential diagnosis must prioritize life-threatening cardiovascular emergencies first—acute coronary syndrome, pulmonary embolism, and aortic dissection—followed by pregnancy-related arrhythmias and benign physiologic causes, as timely diagnosis is often delayed when symptoms are incorrectly attributed to normal pregnancy changes. 1

Life-Threatening Cardiovascular Emergencies (Rule Out First)

Acute Coronary Syndrome (ACS)

• Spontaneous coronary artery dissection is more prevalent in pregnant than non-pregnant women, though more common peripartum than at 14 weeks 1
• Risk factors include smoking, hypertension, hyperlipidemia, older maternal age, diabetes, and positive family history 1
• Diagnostic criteria remain chest pain, ECG changes, and elevated troponin I—even if pre-eclampsia is present, elevated troponin should prompt consideration of ischemic heart disease 1
• Critical pitfall: Negative T-waves appear at increased rates in pregnancy in non-ischemic conditions, potentially causing diagnostic confusion 1
• Maternal mortality from ACS is 5-10%, highest peripartum but can occur at any gestational stage 1

Pulmonary Embolism (PE)

• Clinical indications include dyspnea (most common at 62%), pleuritic chest pain (55%), tachycardia, hypoxemia, cough (24%), and sweating (18%) 1
• D-dimer is inadequate to rule out PE in pregnancy: sensitivity only 73%, specificity 15%, with documented cases of PE despite negative D-dimer 1
• Tachycardia plus dyspnea occurs in >90% of PE patients 1
• Pregnancy increases thrombotic risk through hypercoagulability, venous stasis, and endothelial changes 1

Aortic Dissection

• Presents with sudden-onset "ripping" chest pain, often described as "worst chest pain of my life," with radiation to upper or lower back 1
• Risk factors include hypertension, known bicuspid aortic valve, or aortic dilation 1
• Pregnancy-related hormonal changes (high progesterone) cause structural collagen changes in vessel walls, increasing dissection risk 1

Cardiac Arrhythmias (Common in Pregnancy)

Supraventricular Tachycardia (SVT)

• Most common arrhythmic cause in pregnancy, occurring in 20-44% of pregnancies 2
• Presents with sudden-onset palpitations, chest tightness, and documented tachycardia 2
• Pregnancy-related hormonal changes, increased catecholamines, and hemodynamic alterations directly promote arrhythmogenesis 2
• Can cause hemodynamic compromise affecting maternal and fetal perfusion if sustained 2

Benign Ectopy (Atrial or Ventricular Premature Beats)

• Most palpitations during pregnancy are benign, caused by increased blood volume, cardiac output, and heart rate 2, 3
• Exacerbated by anxiety, dehydration, caffeine, or physical exertion 2
• Bigeminy or frequent ectopy may present as palpitations with chest discomfort 4

Wolff-Parkinson-White Syndrome or Re-entrant Tachycardia

• More common in younger patients with fast heart rate and palpitations 5
• May be triggered by mechanical stimuli or arrhythmogenic effects of pregnancy 5

Metabolic and Endocrine Causes

Hyperthyroidism/Thyroid Storm

• Can exacerbate or cause arrhythmias including atrial fibrillation or flutter 2
• Presents with tachycardia, diaphoresis, chest discomfort, and palpitations 2
• Thyroid storm can precipitate life-threatening arrhythmias 2

Anemia

• Common postpartum but can occur during pregnancy 4
• Causes compensatory tachycardia and palpitations with potential chest discomfort 4

Benign Physiologic Causes

Normal Cardiovascular Adaptations

• Plasma volume increases early in pregnancy with rising cardiac output through increased stroke volume 6
• These hemodynamic changes contribute to pelvic congestion and sensation of fullness or cramping 6
• Increased sympathetic activity and catecholamines cause physiologic tachycardia 2

Round Ligament Pain with Referred Sensation

• Sharp, brief pains from stretching round ligaments typically felt in lower abdomen/groin but can be perceived as chest tightness 6
• Improves with rest or position changes 6

Non-Cardiac Causes

Gastroesophageal Reflux Disease (GERD)

• Extremely common in pregnancy due to progesterone-induced lower esophageal sphincter relaxation 1
• Can mimic cardiac chest pain but typically related to meals 1

Musculoskeletal Pain

• Positional chest pain, usually nonischemic 1
• Ligamentous laxity from relaxin, progesterone, and estrogen affects thoracic structures 6

Anxiety/Panic Disorder

• Can cause chest tightness, palpitations, and hyperventilation 3
• Diagnosis of exclusion after ruling out organic causes 3

Critical Diagnostic Approach

Immediate evaluation required for:

• Severe, persistent pain unrelieved by rest 6
• Hemodynamic instability (hypotension, persistent dizziness, syncope) 1
• Documented sustained tachycardia with chest pain 2
• Diaphoresis, dyspnea, or hypoxemia accompanying chest pain 1

Initial workup must include:

• 12-lead ECG to assess for ischemic changes, arrhythmias, or prolonged QT 1, 4
• Cardiac biomarkers (troponin I) if ACS suspected 1
• Echocardiography to evaluate wall motion abnormalities and structural disease 1
• Thyroid function tests if tachycardia present 2

Critical pitfall to avoid: Dismissing tachycardia and chest pain as "normal pregnancy changes" without proper evaluation, as serious arrhythmias and structural disease present similarly, and delayed diagnosis increases maternal mortality 2, 7