Patent ID: 7875018

Claim:
A method of manipulating a catheter assembly for accessing a coronary sinus ostium of a patient, the method comprising: disposing an inner catheter member within an outer catheter member, the inner catheter member and the outer catheter member forming at least a portion of the catheter assembly, the outer catheter having a first lumen and the inner catheter having a second lumen, at least a distal end portion of the inner catheter member having a stiffness greater than that of at least a distal end portion of the outer catheter member, the distal end portion of the outer catheter member having a flexible, deflectable distal end including regions of varying stiffness, and the inner catheter member having a distal tip; positioning the catheter assembly proximate the coronary sinus; rotatably advancing the inner catheter member through the outer catheter member toward the deflectable distal end of the outer catheter member; longitudinally displacing the distal tip of the inner catheter member relative to the deflectable distal end of the outer catheter member to alter a shape of the deflectable distal end of the outer catheter member; positioning a portion of the catheter assembly within the coronary sinus ostium of the patient; and delivering a cardiac lead through the first or second lumen into the coronary sinus.