Microphysiology of the pericardium: substrate for intrapericardial therapeutics.

Recent capability to enter the normal effusion-free pericardium has expanded intrapericardial therapy which was formerly restricted to patients with effusive pericardial disease, to intrapericardial treatment of cardiac diseases of all kinds. It is now possible to deposit in the intact pericardium a variety of therapeutic agents targeting the myocardium, valves, conduction system and even the endocardium. In addition to such specific agents, the unique microphysiology of the pericardial mesothelium provides investigators with 2 entirely new applications of intrapericardial therapy: 1. supplementing substances like prostanoids and a variety of immune factors, and 2. stimulating pericardial production of such products of metabolism, e.g., superfusion of the normal pericardium by non-steroidal antiinflammatory agents to stimulate prostanoid production with a variety of effects including possible inhibition of coronary thrombosis. Continuing research and development should determine the precise roles of these new applications in human medicine.