Phonocardiographic image-based atrioventricular delay optimization

A cardiac rhythm management system, comprising:

• an implantable device including:
• a sensing circuit to sense a cardiac signal;
• and
• a therapy circuit to deliver pacing pulses;
• an acoustic sensor to produce an acoustic sensor signal indicative of heart sounds;
• and
• an external programmer communicatively coupled to the implantable device and the acoustic sensor, the external programmer including:
• a controller communicatively coupled to the therapy circuit, the controller including:
• a therapy protocol synthesizer adapted to generate a sequence of pacing parameters;
• and
• an automatic therapy protocol execution module adapted to time pacing pulse deliveries each associated with one parameter of the sequence of pacing parameters;
• and
• a processor communicatively coupled to the sensing circuit, the acoustic sensor, and the controller, the processor including an image formation module adapted to produce a phonocardiographic image based on the cardiac signal and the acoustic sensor signal, the phonocardiographic image including a stack of segments of the acoustic sensor signal aligned by a selected type of the cardiac events and grouped by at least parameters of the sequence of pacing parameters.

A method for apply pacing pulses to a heart, the method comprising:

• generating a first sequence of atrioventricular delays (AVDs);
• delivering a first sequence of pacing pulses each associated with one AVD of the first sequence of AVDs;
• receiving a cardiac signal indicative of cardiac events during the delivering the first sequence of pacing pulses;
• receiving an acoustic sensor signal indicative of heart sounds during the delivering the first sequence of pacing pulses;
• and
• forming a phonocardiographic image based on the cardiac signal and the acoustic sensor signal, the phonocardiographic image including a stack of segments of the acoustic sensor signal aligned by a selected type of the cardiac events and grouped by at least the first sequence of AVDs;
• and
• presenting the phonocardiographic image.

A method comprising;

• receiving an acoustic sensor signal indicative of an intrinsic heart sound associated with an intrinsic ventricular contraction adjacently subsequent to a first atrial contraction and a paced heart sound associated with a paced ventricular contraction adjacently subsequent to a second atrial contraction;
• receiving a cardiac signal temporally associated with the acoustic sensor signal, the cardiac signal indicative of the first and second atrial contractions;
• measuring a first time interval between the first atrial contraction and the intrinsic heart sound;
• measuring a second time interval between the second atrial contraction and the paced heart sound;
• and
• determining an approximately optimal pacing therapy based on the first and second time intervals.

A system for applying pacing pulses to a heart, the system comprising:

• means for producing an acoustic sensor signal indicative of heart sounds;
• means for delivering pacing pulses associated with a predetermined sequence of pacing parameters;
• and
• means for producing a phonocardiographic image based on selected type cardiac events and the acoustic sensor signal, the phonocardiographic image including a stack of segments of the acoustic sensor signal aligned by the selected type cardiac events and grouped by at least parameters of the predetermined sequence of pacing parameters.