A system for treating a heart within a patient, the heart having first and second chambers with a septum therebetween, the second chamber having an exterior wall, the system comprising: a first elongate shaft having a proximal end and a distal end, the distal end of the first shaft being configured to be advanced from outside the patient into the heart along a first path so that the distal end of the first shaft is disposed in the first chamber; a second elongate shaft having a proximal end and a distal end; a first elongate flexible body slidably coupled to one of the shafts, the first flexible body having a distal end portion configured for in situ coupling, within the first chamber of the heart, with a corresponding distal end portion extending from the other of the shafts so as to join the first path with the second path; wherein the distal end of the second shaft is configured to be advanced along a second path from outside the heart, through the exterior wall and through the septum so that the distal end of the second shaft is disposed in the first chamber; and the system further comprises: an implant configured to be advanced along the joined paths, the implant including: a first anchor having a low profile configuration for advancement of the first anchor along the joined paths; a second anchor; and an elongate tension member having a first end couplable with the first anchor and a second end coupleable with the second anchor, the first anchor configured to deploy laterally from the low-profile configuration within the first chamber, the tension member configured to extend from the first anchor in the first chamber, through the septum, through the second chamber, and through the exterior wall such that applying tension between the anchors with the tension member urges the septum and the external wall to engage. a first elongate shaft having a proximal end and a distal end, the distal end of the first shaft being configured to be advanced from outside the patient into the heart along a first path so that the distal end of the first shaft is disposed in the first chamber; a second elongate shaft having a proximal end and a distal end; a first elongate flexible body slidably coupled to one of the shafts, the first flexible body having a distal end portion configured for in situ coupling, within the first chamber of the heart, with a corresponding distal end portion extending from the other of the shafts so as to join the first path with the second path; an implant configured to be advanced along the joined paths, the implant including: a first anchor having a low profile configuration for advancement of the first anchor along the joined paths; a second anchor; and an elongate tension member having a first end couplable with the first anchor and a second end coupleable with the second anchor, the first anchor configured to deploy laterally from the low-profile configuration within the first chamber, the tension member configured to extend from the first anchor in the first chamber, through the septum, through the second chamber, and through the exterior wall such that applying tension between the anchors with the tension member urges the septum and the external wall to engage. a first anchor having a low profile configuration for advancement of the first anchor along the joined paths; a second anchor; and an elongate tension member having a first end couplable with the first anchor and a second end coupleable with the second anchor, the first anchor configured to deploy laterally from the low-profile configuration within the first chamber, the tension member configured to extend from the first anchor in the first chamber, through the septum, through the second chamber, and through the exterior wall such that applying tension between the anchors with the tension member urges the septum and the external wall to engage.