Cardiac mapping catheter

A catheter comprising:

• an elongate catheter body having a distal end and a proximal end;
• a proximal handle segment having an articulation control and a deployment control, said proximal handle segment connected to said proximal end;
• an intermediate segment connected to said handle segment;
• a deflectable segment connected to said intermediate segment, said deflectable segment adapted to articulate in a plane through an angle in response to said articulation control;
• a distal array segment connected to said deflectable segment, said distal array segment including a deployable electrode array that can move from a first retracted position to a second deployed position;
• a deployment mechanism coupled to said deployment control for coupling motion of said deployment control to said deployable electrode array, the deployment mechanism comprising:
• an elongate rotatable member coupled to said deployment control;
• a first threaded member disposed and anchored in said distal array segment;
• a second threaded member coupled to said elongate rotatable member;
• said first and second threaded members adapted for engagement by rotation of said rotatable member to cause the electrode array to deploy into said second deployed position and maintain the distal array in the second deployed position during articulation of deflectable segment.