Implantable systems and methods for monitoring bnp levels, hf and mi

An implantable system for monitoring a patient's level of B-type natriuretic peptide (BNP), comprising:

• a pulse generator, connectable to at least one implanted lead, and configured to provide pacing stimulation to at least one of the patient's ventricles;
• a sensing circuit, connectable to at least one implanted lead, and configured to obtain a ventricular intracardiac electrogram (IEGM) indicative of a ventricular evoked response to at least one of the patient's ventricles being paced;
• a ventricular evoked response monitor to determine, based on the ventricular IEGM, at least one ventricular evoked response metric indicative of the ventricular evoke response to at least one of the patient's ventricles being paced;
• and
• a BNP monitor to monitor the patient's level of BNP based on the at least one ventricular evoked response metric.

A method for selecting a preferred ventricular pacing energy level, for use by an implanted system including an implanted cardiac device and at least one implanted lead, the method comprising:

• (a) determining a ventricular capture threshold for pacing a ventricle using an implanted lead;
• (b) determining, based on the ventricular capture threshold, a first ventricular pacing energy level that provides for reliable capture of the ventricle;
• (c) determining at least one ventricular evoked response metric for one or more ventricular evoked response that occurs in response to ventricular pacing at the first ventricular pacing energy level;
• (d) determining at least one ventricular evoked response for one or more ventricular evoked response that occurs in response to ventricular pacing at one or more energy level greater than the first ventricular pacing energy level;
• and
• (e) selecting a preferred ventricular pacing energy level to use for ventricular pacing based on the ventricular evoked response metrics determined at (c) and (d);
• wherein step (e) includes selecting a ventricular pacing energy level greater than the first ventricular pacing energy level as the preferred ventricular pacing energy level, based on whether using the energy level greater than the first ventricular pacing energy level provides at least one of the following:
• a reduction in the patient's level of BNP,
• an improved heart failure (HF) condition,
• a reduction in the patient's risk of an acute HF exacerbation, and
• a reduction in the patient's risk of an acute myocardial infarction.