What is the cause of sharp midsternal chest pain in a 43-year-old male with Gastroesophageal Reflux Disease (GERD), occurring randomly at rest, lasting approximately 1 minute, without associated shortness of breath or radiation, in a patient with mild Coronary Artery Disease (CAD) on Computed Tomography (CT) calcium score?

Differential Diagnosis for Sharp Midsternal Chest Pain

Single Most Likely Diagnosis

• Esophageal Spasm: The patient's history of GERD, sharp midsternal chest pain that occurs randomly and lasts about 1 minute, and the absence of shortness of breath or radiation of pain, are all consistent with esophageal spasm. The fact that the pain occurs at rest and is not triggered by exertion also supports this diagnosis.

Other Likely Diagnoses

• Gastroesophageal Reflux Disease (GERD) Exacerbation: Given the patient's history of GERD, it is possible that the chest pain is related to an exacerbation of GERD symptoms.
• Musculoskeletal Chest Pain: The sharp, midsternal nature of the pain could be consistent with musculoskeletal chest pain, possibly related to costochondritis or other musculoskeletal issues.
• Anxiety-Related Chest Pain: The random occurrence of pain and the absence of other symptoms could suggest an anxiety-related component to the chest pain.

Do Not Miss Diagnoses

• Acute Coronary Syndrome (ACS): Although the patient has mild CAD on CT calcium score and is able to exercise without symptoms, it is crucial not to miss ACS, as it can be life-threatening. The presence of chest pain, even if atypical, warrants consideration of ACS.
• Pulmonary Embolism (PE): Although the patient does not have shortness of breath, PE can present with atypical symptoms, including chest pain. It is essential to consider PE, especially if there are any other risk factors present.
• Aortic Dissection: This is a rare but life-threatening condition that can present with sudden, severe chest pain. Although the patient's pain is sharp and midsternal, aortic dissection must be considered, especially if there are any other symptoms such as back pain or unequal blood pressures in the arms.

Rare Diagnoses

• Pericarditis: This is an inflammation of the pericardium that can cause sharp, chest pain. Although it is less likely, it is essential to consider pericarditis, especially if there are any other symptoms such as fever or a pericardial friction rub.
• Esophageal Rupture: This is a rare but life-threatening condition that can cause severe chest pain. Although the patient's symptoms are not typical, esophageal rupture must be considered, especially if there is any history of vomiting or other symptoms such as severe abdominal pain.