This study involves individuals who have been diagnosed with heart failure, a condition where the heart does not pump blood as well as it should. For this study, a new software program called ALLEVIATE-HF will be studied to see if the software program can help predict worsening heart failure symptoms. The software program will be put onto a medical device called the Reveal LINQ Insertable Cardiac Monitoring (ICM) System. Some participants may already have the Reveal LINQ ICM. If a participant does not already have a Reveal LINQ ICM, then the device will be inserted under the skin. The ALLEVIATE-HF software will help the device identify problems related to heart failure. The device will collect data such as the subjects heart rate and activity level. The information gathered by this system will help the study doctor/healthcare provider and the study team understand an individual subject's risk of having a heart failure event (worsening heart failure symptoms requiring additional treatment or hospitalization) so that steps can be taken to manage their heart failure.

The study will last at least 7 months but may last up to 3 years. There will be at least 2 but up to 4 visits during the study.

The purpose of the study is to test a new way to pace the left side of the heart without using pacing leads, using the WiSE CRT System. In this study, ultrasound will be used to transfer energy from a new type of pacemaker through your body to a special receiver that is placed inside the left ventricle of your heart. The receiver will use the ultrasound energy to pace the heart without using pacing leads.