Subjects with cardiac disorders will be tested in the sleep laboratory with a conventional full-night PSG recording along with WP 200/WP200U ambulatory sleep diagnostic device in a synchronized manner.

The PSG data will be scored manually by a trained polysomnographic scorer, according to standard criteria for this clinical routine.

The data obtained by the WP200/WP200U will be analyzed automatically for RDI, AHI, sleep stages, snoring (optional) and body position (optional), in addition to parameters specific to cardiac subjects. The analysis will be performed by the WP200/WP200U software (zzzPAT) and will be compared to the PSG's manual scoring which serves as a "Gold Standard".

Subjects with cardiac disorders, referred to the sleep lab will be offered to participate in the study. Subjects will be asked to sign an informed consent form and will be screened for inclusion exclusion criteria.

Subject demographic and medical information will be acquired from the subject himself and/or from the subject's medical chart and will be recorded on the appropriate pre-study electronic case report forms.

The subjects will be admitted to the clinical sleep laboratory for one night, during which they will undergo conventional full night PSG recording with the standard PSG channels. The WP 200/WP200U wrist device, which includes the PAT and pulse oximeter probes will be worn on the wrist.

The investigator will not have access to the WP200/WP200U data while scoring the PSG data. During the study recording, the WP200/WP200U data will be recorded inside the device, without being displayed on the PSG monitor. Furthermore, the WP200/WP200U analysis is done automatically without knowledge of the PSG scoring results.

Inclusion Criteria:

• Age between17-90
• Subject is able to read understand and sign the informed consent form.
• Subject with diagnosed cardiac disorders and/or other comorbidity
• Willing to sleep with the WP200/WP200U and PSG simultaneously in the sleep lab

Exclusion Criteria:

• Permanent pacemaker: atrial pacing or VVI without sinus rhythm
• Finger deformity that precludes adequate sensor appliance.
• Use of one of the following medications: alpha blockers, short acting nitrates (less than 3 hours before the study)

Adults with cardiac disorder, referred to the sleep lab for a night study, who consent to undergo an overnight sleep study in the clinical sleep laboratory.