†(a) dissection of the heart (obsolete rare); (b) (originally) insertion of a syringe or scalpel into the heart; (in later use) spec. opening of…

Surgical incision into the pericardium; an instance of this.

= pericardiotomy, n.

surgical removal of adhesions or other tissue around the heart, performed to improve its function.

An operation in which an incision is made into a valve, esp. of the heart.

= pericardiectomy, n.

Surgical removal of all or part of the pericardium; an instance of this.

= valvotomy, n.