The LINQ QT Study is a prospective, non-randomized, multi-center, observational, post-market clinical study investigating QT interval changes due to antiarrhythmic drug loading.

The purpose of this study is to determine if QT interval changes are detected during and after antiarrhythmic drug loading by the designed QT detection algorithm from LINQ ECG.

The QT intervals during the anti arrhythmic loading hospitalization period will be compared for all patients to analyze QT changes that may be caused due to antiarrhythmic drugs.

Inclusion Criteria:

• Patients implanted with LINQ/LINQII prior to the study enrollment (no more than 50% patients implanted with LINQII), but no greater than 2.5 years for LINQ or 3.5 years for LINQII, or patients who are indicated to receive a LINQ/LINQII implant at least 7 days prior to antiarrhythmic drug loading
• Patients who are scheduled to receive antiarrhythmic drug loading
• Age 18-80
• Patient is willing and able to comply with the protocol, including follow-up visits, and performing Holter recordings and patient activation transmissions

Exclusion Criteria:

• Patients who have a contraindication to long-term antiarrhythmic therapy
• Patients not suitable for long-term antiarrhythmic therapy
• Patients with a previous, existing cardiac implantation (i.e., cardiac pacemaker or cardiac resynchronization requiring > 40% pacing, implantable cardioverter defibrillator (ICDs))
• Patients with permanent and persistent AF
• Co-enrollment in another study or planning to participate in a concurrent device study during the course of this clinical study that could confound the results

The subject population for the LINQ QT Study is a patient implanted with LINQ/LINQII or scheduled for a LINQ/LINQII and who are scheduled to receive an antiarrhythmic drug loading, may undergo this study.

There is no plan to share individual patient data with other researchers who were not investigators in the clinical study.

Subjects with Completed Baseline and AA-loading Event

90 days

Continuous telemetered ICM ECG data available during the index antiarrhythmic loading hospitalization period was collected and available in 8 out of 21 patients enrolled (avg. age 68±6.5 years, 63% males) in the QT study and were included in this analysis. 12-lead ECG data was not available for 13 enrolled subjects due to Holter compatibility and technical issues.