Atypical Chest Pain from Myofascial Pain Syndrome of Subscapularis Muscle

Background: Myofascial pain syndrome [MPS] of chest, neck, and shoulder muscles is one of the causes of atypical chest pain, which has often been underscored in the evaluation of patients with chest pain. Findings: We present two cases of MPS of the subscapularis muscle, which presented with atypical chest pain and were apparently underdiagnosed by the management team. They were successfully treated when the correct diagnosis was made. Conclusions: Based on exclusion criteria of atypical chest pain and therapeutic response to trigger point injection, we concluded that MPS of the subscapularis muscle might present with atypical chest pain beside common presentation with "frozen shoulder."