Differential Diagnosis

The patient's presentation of sudden onset left-sided chest discomfort, accompanied by diaphoresis, nausea, and a sensation of impending headache, warrants a thorough evaluation of potential causes. The differential diagnosis can be categorized as follows:

• Single Most Likely Diagnosis

  • Acute Coronary Syndrome (ACS): Given the patient's family history of cardiac disease, history of PCOS (which increases the risk of cardiovascular disease), and the nature of the chest discomfort, ACS is a leading consideration. The symptoms of diaphoresis, nausea, and the brief but intense nature of the pain are consistent with a cardiac event.

• Other Likely Diagnoses

  • Panic Attack: Although the patient distinguishes this episode from previous anxiety attacks, the presence of anxiety and depression in her history, along with symptoms like diaphoresis and nausea, means a panic attack should be considered, especially given the atypical presentation of cardiac symptoms in women.
  • Gastroesophageal Reflux Disease (GERD): The patient's complaint of oral discomfort under the tongue and abnormal stomach sensations could suggest GERD, which can sometimes present with chest discomfort.
  • Musculoskeletal Pain: The vague discomfort across the back could indicate a musculoskeletal issue, although this would not fully explain the acute onset of other symptoms.

• Do Not Miss Diagnoses

  • Aortic Dissection: Although less likely, aortic dissection is a critical diagnosis that must be considered due to its high mortality rate. The sudden onset of severe pain and the presence of a family history of cardiac disease make it essential to rule out this condition.
  • Pulmonary Embolism (PE): Given the acute onset of symptoms and the presence of dizziness, PE should be considered, especially if there are any risk factors for thromboembolic disease.
  • Esophageal Rupture: This is a rare but life-threatening condition that could present with severe chest pain and should be considered, especially if there was an episode of severe vomiting.

• Rare Diagnoses

  • Pericarditis: Inflammation of the pericardium could cause chest pain and should be considered, especially if there's a history of recent viral illness or autoimmune disease.
  • Spontaneous Coronary Artery Dissection (SCAD): This is a rare cause of ACS, more common in women, and should be considered given the patient's demographics and presentation.

Initial Management

Given the differential diagnoses, initial management should focus on stabilizing the patient and further evaluating for the most critical conditions. This may include:

• Electrocardiogram (ECG): To evaluate for signs of ischemia or infarction.
• Troponin levels: To assess for myocardial damage.
• Chest X-ray: To evaluate lung fields and cardiac silhouette.
• D-dimer: If pulmonary embolism is suspected.
• Echocardiogram: To evaluate cardiac function and structure.
• CT angiogram of the chest: If aortic dissection is suspected.
• Basic metabolic panel and complete blood count: To evaluate for other potential causes of symptoms.

The patient should be placed on cardiac monitoring and given aspirin if there's no contraindication, pending further evaluation. Oxygen should be administered if the patient is hypoxic. Nitroglycerin could be considered if the patient has ongoing chest pain and there are no contraindications. Morphine may be used for pain relief in the setting of suspected ACS. However, all interventions should be guided by the results of diagnostic tests and clinical judgment.