A catheter system for crossing into the left heart from the right heart comprising: a. a first inner catheter, having a sheath and a first working lumen, a first proximal end and having a first distal end; b. a first outer catheter having a first outer catheter working lumen sized to accept said first inner catheter, and having a first outer catheter distal end and having a first outer catheter proximal end, the first outer catheter distal end having a distal tip mechanically engaged with a control knob positioned at the first outer catheter proximal end, whereby when the knob is turned the distal tip moves relative to a longitudinal axis of the distal end a specified distance and angle; c. a first inner catheter coupler on said first inner catheter; d. a first outer catheter coupler on said first outer catheter, adapted for mating engagement with said first inner catheter coupler to prevent any relative rotational movement between the coupled first inner catheter and the first outer catheter; e. a first handle coupled to said first proximal end of said first inner catheter, and having a thumb actuated lever to advance a piercing needle of the first distal end of said first inner catheter into a deployed state; f. a spring located within said first handle adapted to bias said piecing needle in a retracted state; and g. an electrical connector (120, 130) located in said first handle to electrically connect to said piercing needle such that the piercing needle is also an electrode, in the retracted state the electrode, along with the first distal end, is moved to measure voltage signals wherein each voltage signal is associated with an anatomical region of the heart. a. a first inner catheter, having a sheath and a first working lumen, a first proximal end and having a first distal end; b. a first outer catheter having a first outer catheter working lumen sized to accept said first inner catheter, and having a first outer catheter distal end and having a first outer catheter proximal end, the first outer catheter distal end having a distal tip mechanically engaged with a control knob positioned at the first outer catheter proximal end, whereby when the knob is turned the distal tip moves relative to a longitudinal axis of the distal end a specified distance and angle; c. a first inner catheter coupler on said first inner catheter; d. a first outer catheter coupler on said first outer catheter, adapted for mating engagement with said first inner catheter coupler to prevent any relative rotational movement between the coupled first inner catheter and the first outer catheter; e. a first handle coupled to said first proximal end of said first inner catheter, and having a thumb actuated lever to advance a piercing needle of the first distal end of said first inner catheter into a deployed state; f. a spring located within said first handle adapted to bias said piecing needle in a retracted state; and g. an electrical connector (120, 130) located in said first handle to electrically connect to said piercing needle such that the piercing needle is also an electrode, in the retracted state the electrode, along with the first distal end, is moved to measure voltage signals wherein each voltage signal is associated with an anatomical region of the heart.