Devices, systems, and methods for cardiac resynchronization therapy

1. A wireless system for stimulating the left ventricle of a heart of a human subject having left bundle branch block (LBBB), the system comprising:

a controller-transmitter configured to be implanted in the human subject, the controller-transmitter including—

one or more sensors configured to receive an indication of electrical conduction of the heart,

a controller operably coupled to the one or more sensors and configured to determine, in substantially real-time, an occurrence of an onset of a QRS segment in the electrical conduction of the heart, and

a first transducer operably coupled to the controller and configured to emit an acoustic signal in response to the controller determining the occurrence of the onset of the QRS segment in the electrical conduction of the heart; and

a receiver-stimulator configured to be implanted adjacent to the left ventricle of the human subject, the receiver-stimulator including—

a second transducer configured to (a) receive the acoustic signal emitted from the first transducer and (b) convert the received acoustic signal into electrical energy, and

one or more stimulation electrodes coupled to the second transducer and configured to deliver the electrical energy to the left ventricle of the heart as electrical stimulation;

wherein the system is configured to synchronize contraction of the left ventricle and a right ventricle of the heart by delivering the electrical stimulation to the left ventricle within a predefined duration beginning at the onset of the QRS segment in the electrical conduction of the heart.

2. The wireless system of claim 1 wherein the one or more sensors are configured to detect the electrical conduction of the heart with a delay of less than about 5 milliseconds, less than about 4 milliseconds, less than about 3 milliseconds, less than about 2 milliseconds, or less than about 1 millisecond.

3. The wireless system of claim 1 wherein the predefined duration is less than about 10 milliseconds.

4. The wireless system of claim 1 wherein the predefined duration is about 1 millisecond, about 2 milliseconds, about 3 milliseconds, about 4 milliseconds, about 5 milliseconds, about 10 milliseconds, about 20 milliseconds, about 30 milliseconds, about 40 milliseconds, about 50 milliseconds, about 60 milliseconds, about 70 milliseconds, about 80 milliseconds, about 90 milliseconds, about 100 milliseconds, about 110 milliseconds, or about 120 milliseconds.

5. The wireless system of claim 1 wherein the controller-transmitter further comprises a battery and a battery housing, and wherein at least one of the one or more sensors is attached to the battery housing.

6. The wireless system of claim 1 wherein the controller-transmitter further comprises a housing, and wherein at least one of the one or more sensors is attached to the housing.

7. The wireless system of claim 1 wherein the controller-transmitter further comprises a housing, a battery, and a battery housing, and wherein the one or more sensors include a first sensor and a second sensor, wherein the first sensor is attached to the controller-transmitter housing, and wherein the second sensor is attached to the battery housing.

8. The wireless system of claim 1 wherein the receiver-stimulator further includes a rectifier component configured to convert the electrical energy into an electrical output configured to stimulate the left ventricle.

9. The wireless system of claim 8 wherein the rectifier component is configured to convert AC electrical energy into DC electrical output.

10. The wireless system of claim 1 , further comprising a second receiver-stimulator configured to be implanted adjacent to the left ventricle of the human subject.

11. The wireless system of claim 1 , wherein the controller-transmitter further comprises a communication module configured to provide a data path to an external programmer unit.