Title: Heart Failure Optimization Study (HF-Opt). Description: The goal of the HF Opt Study is to observe new heart failure patients to see if their heart’s pumping ability improves by extending the timeline to optimize medications. Patients will wear the LifeVest to protect them from sudden cardiac death in addition to taking heart failure medications. First, you will be enrolled in a Registry for 90 days where the LifeVest will be prescribed by your doctor to protect you from sudden cardiac arrest, in addition to taking your heart failure medications. As you approach Day 90, the heart failure medications may need more time to improve your heart function. Following a measurement of your heart’s ability to pump, your doctor will place you into one of three study arms and follow you through routine medical care for up to one year, since you started wearing the LifeVest. - If your heart has improved, you may not need to continue to wear the LifeVest. -If your heart shows some improvement, but its pumping function is still low, you will continue to wear the LifeVest while giving the heart failure medication more time to improve your heart function. -If your heart muscle has remained weak which makes pumping difficult, your doctor will discuss other treatment options.