Post-cardiac injury syndrome is a heterogeneous collection of conditions, all of which involve an inciting cardiac injury followed by the development of pericardial inflammation with or without the development of a pericardial effusion. These conditions include post-myocardial infarction syndrome, postpericardiotomy syndrome, and posttraumatic pericarditis.

The inciting injury can range from mild (percutaneous coronary intervention, radiofrequency ablation, pacing wire insertion) to severe (myocardial infarction or cardiac surgery).

The exact incidence of post-cardiac injury syndrome is unclear due to the heterogeneous nature of the condition. More is known for specific etiologies. Post-myocardial infarction pericarditis is thought to occur in less than 5% of cases. Most occur peri-infarction, with less than 1% of cases as late post-myocardial infarction pericarditis (Dressler syndrome). After percutaneous coronary intervention, the rate of post-myocardial injury pericarditis it is believed to be less than 0.5%. In comparison, the rate of postpericardiotomy pericarditis ranges between 10% and 40%.

The exact pathogenesis of this condition is incompletely understood and is believed to be autoimmune in nature.

The majority of patients will present with chest pain (>80%), often pleuritic in nature. Low-grade fever is seen in slightly over half of patients (50%-60%), as is dyspnea (50%-60%). Inflammatory markers (C-reactive protein [CRP], erythrocyte sedimentation rate [ESR]) are elevated, and pericardial effusions are common but often mild. A pericardial rub is auscultated in 30%-60% of cases and electrocardiogram (ECG) changes are identified in 20%.