A system for treating a heart within a patient, the heart having first and second chambers with a septum there between, the second chamber having an external wall, the system comprising: an elongate shaft having a proximal end and a distal end with a lumen extending there between, the distal end of the elongate shaft being configured to be advanced from outside the patient and through the vasculature into the second chamber of the heart so that the distal end of the elongate shaft is disposed in the second chamber, the elongate shaft being steerable so that the distal end of the elongate shaft is repositionable within the second chamber between the septum and the external wall to enable penetration of the septum and external wall; a first guidewire that is deliverable through the lumen of the elongate shaft and through the septum when the distal end of the elongate shaft is positioned adjacent the septum, the first guidewire being deliverable through the septum so that a distal end of the first guidewire is disposed within the first chamber; a second guidewire that is deliverable through the lumen of the elongate shaft and through the external wall when the distal end of the elongate shaft is positioned adjacent the external wall, the second guidewire being deliverable through the external wall so that a distal end of the second guidewire is disposed externally of the external wall; and an external elongate shaft having a proximal end and a distal end, the distal end of the external elongate shaft being configured to be advanced from outside the patient and to the external wall of the second chamber so that the distal end of the external elongate shaft is disposed adjacent the external wall of the second chamber, the external elongate shaft being configured for coupling with the second guidewire for extracting the second guidewire from the external wall to outside the patient body, wherein the first guidewire is coupleable to the second guidewire to join a path within the second chamber that extends between the septum and the external wall. an elongate shaft having a proximal end and a distal end with a lumen extending there between, the distal end of the elongate shaft being configured to be advanced from outside the patient and through the vasculature into the second chamber of the heart so that the distal end of the elongate shaft is disposed in the second chamber, the elongate shaft being steerable so that the distal end of the elongate shaft is repositionable within the second chamber between the septum and the external wall to enable penetration of the septum and external wall; a first guidewire that is deliverable through the lumen of the elongate shaft and through the septum when the distal end of the elongate shaft is positioned adjacent the septum, the first guidewire being deliverable through the septum so that a distal end of the first guidewire is disposed within the first chamber; a second guidewire that is deliverable through the lumen of the elongate shaft and through the external wall when the distal end of the elongate shaft is positioned adjacent the external wall, the second guidewire being deliverable through the external wall so that a distal end of the second guidewire is disposed externally of the external wall; and an external elongate shaft having a proximal end and a distal end, the distal end of the external elongate shaft being configured to be advanced from outside the patient and to the external wall of the second chamber so that the distal end of the external elongate shaft is disposed adjacent the external wall of the second chamber, the external elongate shaft being configured for coupling with the second guidewire for extracting the second guidewire from the external wall to outside the patient body, wherein the first guidewire is coupleable to the second guidewire to join a path within the second chamber that extends between the septum and the external wall.