Methods of using a deflectable telescoping guide catheter

#The invention relates generally to methods of using guide catheters, and, more particularly, to methods of using steerable, telescoping guide catheters to locate and cannulate a destination vessel of a patient, such as the coronary sinus of a patient's heart.

#Guiding catheters are instruments that allow a physician to access and cannulate vessels in a patient's heart for conducting various medical procedures, including venography and implanting of cardiac pacing devices. Cannulating heart vessels requires navigating a small diameter, flexible guide through the tortuous vasculature into a heart chamber, and then into a destination heart vessel. Once the destination heart vessel is reached, the catheter acts as a conduit for insertion of payloads into the vessel.

#A commonly accessed destination vessel for cardiac pacing lead insertion is the coronary sinus. A pre-shaped guiding catheter is typically used to blindly locate the coronary sinus ostium. This endeavor, however, is complicated by the fact that the location of the coronary sinus ostium may vary appreciably from one patient to another, especially among patients with diseased hearts. Oftentimes, the clinician is entirely unable to locate the coronary sinus ostium using the guiding catheter, and must resort to finding the ostium by “mapping” (interpreting localized bipolar waveforms) using an electrophysiological (EP) catheter and an ECG monitor. After the ostium is located, the guiding catheter is typically used to inject radiographic contrast media into the coronary sinus to highlight the associated venous system, and then a pacing lead is installed within one of the coronary branches.

#FIG. 1A is a cut-away view of a patient's heart, showing a catheter embodying features of the present invention deployed within the heart;

#FIG. 1B is an external view of a catheter embodying features of the present invention;

#FIG. 1C is an axial cross section 1-1 from FIG. 1B showing the distal end of an outer guide;

#While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail herein. It is to be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.

#In the following description of the illustrated embodiments, references are made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration, various embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized, and structural and functional changes may be made without departing from the scope of the present invention.

#With reference to FIG. 1A, a distal end of a catheter 100 is illustrated in accordance with an embodiment of the present invention. The catheter 100 includes an outer guide 101 and an inner guide 104. The catheter 100 is shown deployed within a patient's heart, accessing the coronary via the right atrium. A distal end of the inner guide 104 extends from the outer guide 101 as the inner guide 104 is advanced towards the coronary sinus ostium.