The purpose of the Confirm Rx SMART Registry is to collect real world data to assess the safety and performance of the Confirm Rx Insertable Cardiac Monitor (ICM) and system over a 12 month period. A sub-set of subjects enrolled in the Confirm Rx SMART Registry will meet the Post Market Clinical Follow-Up (PMCF) requirement for CE mark.

Inclusion Criteria:

• Have an approved indication for continuous arrhythmia monitoring with an ICM
• Have a cellular phone or the ability or willing to use a St. Jude Medical mobile transmitter that is compatible with the MyMerlin App and able to communicate with the Confirm Rx ICM device.
• Have the ability to provide informed consent for study participation and be willing and able to comply with the prescribed follow-up tests and schedule of evaluations.
• Are 18 years of age or older, or of legal age to give informed consent specific to state and national law.

Exclusion Criteria:

• Subject is implanted with or indicated for implant with a pacemaker, implantable cardioverter defibrillator (ICD), or cardiac resynchronization therapy (CRT) device.
• Enrolled or intend to participate in a clinical drug and/or device study, which could confound the results of this trial as determined by the sponsor, during the course of this clinical study.
• Have a life expectancy of less than 1 year due to any condition.
• Have a previous ICM placement.

Subjects over the age of 18 years (or of legal age specific to state and national law) who experience unexplained symptoms such as: dizziness, palpitations, chest pain, syncope, and shortness of breath, as well as subjects who are at risk for cardiac arrhythmias, have been previously diagnosed with atrial fibrillation, or who are susceptible to developing atrial fibrillation.