Inclusion Criteria:  Subject is implanted with a Moderato implantable pulse generator (IPG) and completed participation in the CS-03 clinical study.  Subject has been treating with continuous, active CNT pacing signals for at least  1 month.  Subject's CNT signal parameters have been stable for at least 1 month. Subject has an average office systolic blood pressure less than 170 mmHg at the sub-study screening visit (with CNT on).  Exclusion Criteria:  Subject has permanent atrial fibrillation. Subject had significant paroxysmal atrial fibrillation/flutter burden (defined as >25% of beats) in the past month. Atrial fibrillation/flutter burden will be determined by interrogation of the Moderato pulse generator. Subject experienced a neurological events (stroke or TIA) within the past year Subject have had a serious adverse event classified as related to CNT or the Backbeat Moderato device. Female subject who is pregnant, breast-feeding, intends to become pregnant or has the possibility of becoming pregnant during the conduct of the study and is not willing to use contraception during the study. Subject cannot or is unwilling to provide informed consent.