In this series, we describe the techniques of atrial, ventricular incision and closure. Right atriotomy is a surgical procedure necessary to expose congenital abnormalities of the tricuspid valve and other congenital heart diseases such as atrial and ventricular septal defects. Whereas, left atriotomy( for example left side atrial, transseptal or superior transseptal incisions) is a technique needed to expose mitral valve disease, frequently used during the maze procedure. And finally, left ventriculostomy is a surgical approach applied during resection of scar tissue or thrombus of ventricular aneurysm surgery, repair of the ventricular septal rupture and endoaneurysmorrhaphy. These are known techniques that have already been described in many manuscripts and textbooks. Regarding atriotomy and ventriculostomy, the most important thing to know is how to expose the tricuspid, mitral valves and adjacent sections of the heart. Ventriculostomy uses strips of teflon felt to strengthen the suture line and enhance hemostasis.