Apparatus and method for septal penetration

An apparatus, comprising:

• a sheath defining a lumen;
• a catheter slidably disposable within the lumen of the sheath and configured to extend distally relative to the sheath, the catheter defining a lumen and having an end effector at a distal end thereof, the end effector configured to transition from first configuration in which the end effector has a first diameter to a second, atraumatic configuration in which the end effector has a second diameter greater than the first diameter;
• a dilator slidably disposable within the lumen of the catheter and configured to extend distally relative to the catheter and the sheath, the dilator defining a lumen;
• a radiofrequency (RF) guidewire slidably disposable within the lumen of the dilator and configured to extend distally relative to the dilator, the distal end portion of the RF guidewire configured to be activated to deliver RF to perforate a target perforation site of a patient.

An apparatus, comprising:

• a sheath;
• a dilator slidably disposable within the sheath and configured to extend distally relative to the sheath, the dilator defining a lumen,
• a distal end portion of the sheath having a lower durometer than a portion of the sheath proximal to the distal end portion of the sheath such that an inner diameter of the distal portion of the sheath is configured to expand and contract laterally according to an outer diameter of the dilator;
• and
• a radiofrequency (RF) guidewire slidably disposable within the lumen of the dilator and configured to extend distally relative to the dilator, the distal end portion of the RF guidewire configured to be activated to deliver RF to perforate a target perforation site of a patient.

A method, comprising:

• navigating a catheter assembly to a right atrium of a patient, the catheter assembly including a sheath and a catheter slidably disposed in the sheath, the catheter including an end effector on a distal end thereof;
• disposing the end effector of the catheter distal to a distal end of the sheath such that the end effector transitions from a first configuration in which the end effector has a first diameter to a second, atraumatic configuration in which the end effector has a second diameter greater than the first diameter;
• tenting a target perforation site of a septum with the end effector;
• and
• perforating, with the target perforation site tented, the target perforation site with the guidewire.