Light up your heart
Nov 19, 1997
Replacing a pacemaker lead without the need for a serious operation has come one step closer.
Pacemakers work by sending a electrical pulse from a pacemaker through a lead to endocardial tissue, a layer of tissue which is then simulated inside the heart. The lead passes into the heart through a vein.
One of the difficulties with installing pacemakers, is deciding which vein to use, and how to cope with the bodies reaction to it. Shortly after placement, blood clots form near the lead caused by the irritation of the endocardial tissue by the leads electrode tip. This keeps the cable in place inside the heart.
Although pacemakers have improved tremendously, sometimes the leads fail, or the tip has to be moved to simulate a different section of the heart, resulting in additional operations to the patient. Because of this some patients may come to have as many as four or five unused leads in their heart.
Some of the methods to remove the lead are quite dangerous. Patent 5674217 uses a new solution involving a laser.
A lead extraction device containing a catheter to overlap the damaged lead is inserted into the beating heart with its movements synchronized to the cardiac cycle. The catheter is thereby guided by the lead. The catheter has at least one optical fiber to emit laser light from the distal end and thereby separate the lead from fibrous scar tissue. Laser light is then used to separate the pacemaker lead, from fibrous scar tissue and thereby permit the implanted object to be extracted from a body.
The extraction device features a catheter having a central lumen dimensioned so a pacemaker lead will fit within. A means for generating a control pulse in response to a sensed ECG signal permits the catheter to by synchronized to the cardiac cycle. In such a manner laser light may be controlled so as to avoid striking the heart at a vulnerable period in the cardiac cycle.