This study will obtain device-human interaction evaluations for the HWD1000 within the controlled environment of the hospital as well as establish that the safety profile is similar to outpatient wearable cardioverter-defibrillators use.

A multi-center prospective study of hospitalized patients whom a physician deems at risk of sudden cardiac arrest during the hospitalization period, wearing the HWD1000 hospital wearable defibrillator in order to evaluate caregiver and patient interactions with the device. In addition, ECG signal quality will be reviewed to confirm the HWD1000 safety profile.

Inclusion Criteria:

Patients whom a physician deems at risk of sudden cardiac arrest during the hospitalization period (patients will be monitored using the hospital's telemetry system). Specific inclusion criteria are:

• Hospitalized patients having continuous independent ECG monitoring.
• Patients at risk of sudden cardiac arrest during the hospitalization period as determined by the investigating physician.
• Patient ≥18 years of age (over the legal age of providing consent).

Exclusion Criteria:

• Patients with an active implantable cardioverter-defibrillator.
• Patients with an active unipolar pacemaker.
• Patients with physical or mental conditions preventing them from interacting with or wearing the device as determined by the investigating physician.
• Patients having an advanced directive prohibiting resuscitation.
• Patients having bandages or other clinical condition preventing the HWD use.
• Patients unable to consent.
• Patients having recently experienced an arrhythmic storm.
• Patients prone to paroxysmal supraventricular tachycardia.

Hospitalized patients at risk for sudden cardiac arrest.