Coronary artery spasm: This condition is characterized by temporary, sudden narrowing of one of the coronary arteries, which can cause chest pain. The pain can occur at rest or be triggered by specific activities, including sexual intercourse. The fact that the pain occurs during orgasm but not during physical activity suggests a possible vasospastic cause rather than a fixed obstructive lesion.

Hypertrophic cardiomyopathy: Although more commonly associated with exertional chest pain, hypertrophic cardiomyopathy can cause chest pain at any time, including during sexual activity. The mechanism might involve outflow tract obstruction or ischemia.
Pericarditis: Inflammation of the pericardium can cause sharp chest pain that may improve with sitting up and leaning forward. While pericarditis is not typically associated with sexual activity, the pain can be constant and not necessarily related to exertion.
Gastroesophageal reflux disease (GERD): GERD can cause chest pain that is not necessarily related to physical exertion. The act of orgasm could potentially trigger or exacerbate reflux in susceptible individuals.

Aortic dissection: Although rare, aortic dissection is a life-threatening condition that requires immediate medical attention. The pain is often described as tearing or ripping and can be constant, but any chest pain that is severe and atypical should prompt consideration of this diagnosis.
Pulmonary embolism: While pulmonary embolism typically presents with dyspnea, tachypnea, and possibly chest pain that worsens with deep breathing, any unexplained chest pain, especially if accompanied by other symptoms like syncope or palpitations during orgasm, should prompt consideration of this diagnosis.
Myocardial infarction: While less likely if the pain only occurs during orgasm and not with physical activity, myocardial infarction can present atypically, especially in women or diabetic patients. It is crucial not to miss this diagnosis due to its high morbidity and mortality.

Pneumothorax: Spontaneous pneumothorax can cause sudden onset of chest pain and shortness of breath. It is rare but could potentially be triggered by the physical exertion associated with sexual activity.
Esophageal rupture or esophagitis: These conditions can cause severe chest pain but are less commonly associated with sexual activity. However, forceful or vigorous activity could theoretically contribute to esophageal injury in susceptible individuals.