An apparatus to monitor at least one sleep parameter and/or at least one cardiac parameter. In at least some examples cardiac monitoring may be employed in association with a therapy for sleep disordered breathing. In some instances such cardiac monitoring may help demonstrate long term efficacy of sleep disordered breathing therapy in improving cardiac health or in slowing down progression of negative cardiac conditions (e.g. cardiac disorders). In some instances such cardiac monitoring may help identify negative cardiac conditions which are not alleviated despite efficacious sleep disordered breathing therapy and thereby facilitate the diagnosis and treatment of such cardiac conditions.
