II. Indications
- Nondiagnostic EKG and high suspicion for Arrhythmia
- Structural heart disease
- Family History of Sudden Cardiac Death
- Inherited channelopathy (e.g. Long QTc Syndrome)
- Syncope or Near Syncope
- Palpitations
III. Diagnostics: Devices
- Holter Monitor
- Bulky, Continuous EKG Monitor worn for 24-48 hours
- Patient keeps a diary of symptoms during monitoring
- Continuous recording if episode occurs while monitored
- Low yield given short duration (diagnostic in 10-15% of cases)
- Indicated for daily symptoms (e.g. Palpitations)
- Event Monitor
- Small single lead device connected to worn continuous loop recorder for up to 1 month
- Requires patient to push a button when symptomatic, and record a diary of events
- Event Monitor only saves recording when button pushed
- Records a few minutes before and after event
- May typically record up to 4 episodes
- Does not save tracings if Arrhythmia is asymptomatic
- Indicated for weekly to monthly symptoms
- Recordings transmitted via phone to lab for analysis
- Patch EKG Monitor (Zio, CAM)
- Single lead small device applied to chest for up to 14 days (without other monitor)
- Single use device that may be worn during showering and Exercise
- Indicated for weekly symptoms
- Mobile Cardiac Telemetry
- One to three lead external loop recorder transmits to portable receiver and uploads to internet
- Provides realtime cardiac monitoring for up to 30 days
- Indicated for weekly symptoms in higher risk patients
- Similar devices are used on hospital telemetry wards
- Implantable Loop recorders
- Subcutaneous device implant records single lead for up to 36 months (limited by battery life)
- Indicated in monthly symptoms, cryptogenic stroke, recurrent Syncope, Atrial Fib. following ablation
- Highest yield device (diagnostic in 80-90% of cases, esp. for infrequent symptoms) but most invasive
- Wearable SmartPhone Based Ambulatory Cardiac Monitors
- Various consumer devices and software applications (e.g. Apple Smartwatch EKG, KardiaMobile)
- Many of the devices are FDA approved for Atrial Fibrillation detection with high efficacy
IV. Efficacy
- Highest yield duration of monitoring is 14 days (diagnostic in 70 to 85% of cases)