Multi-site pacing capture verification

A method for evaluating electrostimulation of a heart, comprising:

• receiving first and second heart sound (HS) signals, the first HS signal obtained in response to electrostimulation to a first site of the heart during a first cardiac cycle capturing at least a portion of the heart, and the second HS signal obtained in response to electrostimulation to a different second site of the heart during a second cardiac cycle capturing at least a portion of the heart;
• delivering electrostimulation to two or more sites of the heart during a third cardiac cycle, separated by a specified temporal offset that is less than a sensed or paced time interval value of the third cardiac cycle, the two or more sites including the first and second sites of the heart;
• sensing a third HS signal during the delivery of the electrostimulation to the two or more sites of the heart;
• and
• determining a capture status indication using the third HS signal and at least one of the first or second HS signals,
• wherein the capture status indication indicates whether the electrostimulation of the two or more sites captures the two or more sites of the heart, and includes one or more of a full capture indication, a partial capture indication, or a loss of capture indication;
• wherein the full capture indication indicates that each of the two or more sites is captured by the electrostimulation;
• wherein the partial capture indication indicates that at least one of the two or more sites is captured by the electrostimulation, and at least another one of the two or more sites is not captured by the electrostimulation;
• and
• wherein the loss of capture indication indicates none of the two or more sites is captured by the electrostimulation.