Delivery of cardiac stimulation devices
Some embodiments of an electrical stimulation system employ wireless electrode assemblies to provide pacing therapy, defibrillation therapy, or other stimulation therapy. In certain embodiments, the wireless electrode assemblies may include a guide wire channel so that each electrode assembly can be advanced over a guide wire instrument through the endocardium. For example, a distal tip portion of a guide wire instrument can penetrate through the endocardium and into the myocardial wall of a heart chamber, and the electrode assembly may then be advanced over the guide wire and into the heart chamber wall. In such circumstances, the guide wire instrument (and other portions of the delivery system) can be retracted from the heart chamber wall, thereby leaving the electrode assembly embedded in the heart tissue.
1. A system, comprising:
an intravascularly-deliverable medical device including a fixation device configured to engage heart wall tissue and configured such that the intravascular-deliverable medical device abuts the heart wall tissue and does not penetrate the heart wall tissue when the fixation device engages the heat wall tissue; and
a guide sheath defining a first lumen, the guide sheath configured to direct the intravascularly-deliverable medical device to the heart wall tissue via the first lumen;
wherein the fixation device comprises:
four tines having a non-deployed configuration and a deployed configuration, wherein in the non-deployed configuration the four tines point distally toward a distal end of the intravascularly-deliverable medical device to pierce into heart wall tissue to engage the heart wall tissue, and wherein the four tines are configured to curl outwardly from the distal end when in the deployed configuration; and
wherein the system includes an actuator configured to move the four tines from the non-deployed configuration to the deployed configuration.
2. The system of claim 1 , wherein the four tines are configured to have a generally longitudinal orientation when in the non-deployed configuration.
3. The system of claim 1 , wherein distal movement of the actuator moves the four tines from the non-deployed configuration to the deployed configuration.
4. The system of claim 1 , wherein the four tines include a shape-memory material.
5. The system of claim 1 , wherein the four tines are configured to move linearly in a longitudinal direction in response to a rotational actuation of the actuator.
6. The system of claim 1 , wherein the actuator defines a second lumen, the second lumen sized and shaped to receive a guidewire therethrough.
7. The system of claim 1 , wherein the deployed configuration the four tines extend distally from the distal end of the intravascularly-deliverable medical device to pierce into heart wall tissue without penetrating entirely through the heart wall tissue to an opposite face of the heart wall tissue.
8. A system, comprising:
an intravascularly-deliverable medical device including a fixation device configured to engage heart wall tissue and configured such that the intravascular-deliverable medical device abuts the heart wall tissue and does not penetrate the heart wall tissue when the fixation device engages the heart wall tissue; and
a guide sheath defining a first lumen, the guide sheath configured to direct the intravascularly-deliverable medical device to the heart wall tissue via the first lumen;
wherein the fixation device comprises:
four tines configured to deploy from a distal end of the intravascularly-deliverable medical device to anchor the intravascularly-deliverable medical device by piercing into the heart wall tissue; and
wherein the four tines are configured to deploy in response to user actuation of the intravascularly-deliverable medical device in a longitudinal direction along a longitudinal axis of the guide sheath.
9. The system of claim 8 , wherein the four tines are configured to curl outwardly from a distal tip region of the intravascularly-deliverable medical device when deployed form the intravascularly-deliverable medical device.
10. The system of claim 8 , wherein the four tines include a shape-memory material.
11. The system of claim 8 , comprising an actuator sized and shaped for insertion into the first lumen of the guide sheath and configured to actuate the four tines; and
wherein the four tines are configured to deploy from a distal end of the intravascularly-deliverable medical device into the heart wall tissue in response to user actuation via the actuator.
12. The system of claim 11 , wherein the four tines are configured to move linearly in a longitudinal direction in response to a rotational actuation of the actuator.
13. The system of claim 8 , wherein the four tines are configured to deploy from the distal end of the intravascularly-deliverable medical device to anchor the intravascularly-deliverable medical device by piercing into the heart wall tissue without penetrating entirely through the heart wall tissue to an opposite face of the heart wall tissue.
14. A system, comprising:
an intravascularly-deliverable medical device including a fixation device configured to engage heart wall tissue; and
a guide sheath defining a first lumen, the guide sheath configured to direct the intravascularly-deliverable medical device to the heart wall tissue via the first lumen;
wherein the fixation device comprises:
four tines having a non-deployed configuration and a deployed configuration, wherein in the non-deployed configuration the four tines point distally toward a distal end of the intravascularly-deliverable medical device to pierce into heart wall tissue to engage the heart wall tissue, and wherein the four tines are configured to curl outwardly from the distal end when in the deployed configuration; and
wherein the system includes an actuator configured to move the four tines from the non-deployed configuration to the deployed configuration;
wherein the four tines are configured to deploy from the distal end of the intravascularly-deliverable medical device to anchor the intravascularly-deliverable medical device by piercing into the heart wall tissue without penetrating entirely through the heart wall tissue to an opposite face of the heart wall tissue.