The primary objective of this pilot study is to document the percentage achievement in effective HR control (average nighttime HR < 70 bpm) during WCD use in a cohort of female patients with cardiomyopathy in an outpatient setting using continuous heart rate (HR) trends data from the WCD to optimize BB/ivabradine dosage, as compared to a prior historical control.

The primary objective of this pilot study is to document the percentage achievement in effective HR control (average nighttime HR < 70 bpm) during WCD use in a cohort of female patients with cardiomyopathy in an outpatient setting using continuous heart rate (HR) trends data from the WCD to optimize BB/ivabradine dosage, as compared to a prior historical control.

Adult female patients (18 years or older) who are prescribed the wearable cardioverter defibrillator (WCD) for 3 months for ischemic or non-ischemic cardiomyopathy with a low ejection fraction.

Subjects will wear an FDA-approved WCD with a 3 month follow-up period. Heart rate (HR) will be continuously monitored by the WCD. Every two weeks a report showing daily HR trends will be emailed to the healthcare provider. The healthcare provider will also receive a HR control alert if the HR exceeds a predetermined threshold for 3 days in a row.

Based on this information, clinicians should follow guideline-directed medical therapy (GDMT) to add or titrate medication accordingly. The goal of these changes will be to achieve the average nighttime HR to recommended guidelines (<70 bpm) by the end of WCD use.

Inclusion Criteria for Screening Phase:

• Female patients with newly diagnosed (never hospitalized for HF in the last 30 days prior to enrollment) ischemic or non-ischemic cardiomyopathy and an EF ≤ 35% at the time of WCD prescription.
• Patients prescribed the WCD for an intended 90 ± 14 days of use.
• Patients have used the WCD for no more than 14 days from the day of consent.
• Patients 18 years of age or older at the time of consent.

Inclusion Criteria for Continuation Phase:

-After the first 2 weeks of WCD wear, only actively wearing patients averaging at least 105 hours of WCD wear per week (or 15 hours/day) are eligible to continue.

Exclusion Criteria for Screening Phase:

• Patients with a known contraindication or intolerance to beta-blocker therapy.
• Patients with permanent atrial fibrillation.
• Patients who have a pacemaker.
• Patients with a current or prior implantable cardioverter defibrillator (ICD).
• Patients who are self-reporting to be pregnant.
• Patients with known congenital or inherited heart disease.
• Patients participating in another interventional clinical trial.
• Patients not expected to live longer than 3 months.

Exclusion Criteria for Continuation Phase:

-Patients ending WCD use within the first two weeks of use.