Systems and methods for shrinking and/or securing cardiovascular tissue

A method for treating cardiac tissue, the cardiac tissue including a primum, a secundum adjacent to the primum, and a patent foramen ovale, the method comprising:

• releasably tightening the primum at a first location spaced apart from the patent foramen ovale by drawing portions of the primum together;
• while the primum is releasably tightened, at least partially sealing the patent foramen ovale by applying energy at a second location at least closer to the patent foramen ovale than the first location;
• and
• releasing tension on the primum after at least partially sealing the patent foramen ovale and allowing the portions of the primum to move apart from each other.

A method for treating cardiac tissue, the cardiac tissue including a primum, a secundum adjacent to the primum, and a foramen ovale having a patency in the form of a tunnel between the primum and the secundum, the method comprising:

• inserting a catheter into a patient's heart;
• heating the primum at a location spaced apart from the patent foramen ovale to shrink the primum;
• moving at least a portion of the catheter toward the tunnel, while drawing a vacuum through the catheter via vacuum channels positioned in peripheral portions of at least one electrode located at a distal end of the catheter;
• inserting the distal end of the catheter into the tunnel;
• drawing at least one of the primum and the secundum into contact with the other by applying a vacuum to the primum and secundum from a location between the primum and the secundum and within the tunnel;
• detecting at least one of a drop in evacuated fluid flow and an increase in the differential pressure drawn as at least one of the primum and the secundum is drawn into contact with the other;
• continuing to apply a vacuum through the catheter via the vacuum channels to secure the position of the at least one electrode relative to the primum and the secundum;
• applying radio frequency energy to the primum and the secundum via the at least one electrode to seal the tunnel;
• and
• supplying an electrolyte through a porous portion of the at least one electrode to at least restrict sticking between the at least one electrode and the tunnel.