Long-term Monitoring of Patients With Cardiac Amyloidosis With Implantable Event Monitors

Inclusion Criteria: * Cardiac biopsy or technetium pyrophosphate scintigraphy confirmed patients * Stage I, II, and early and late stage III in numbers as described , irrespective of EF or NYHA functional class * Patients aged 18 -85, both genders and of all races and ethnicities. * Patients must be competent to give informed consent. * Patients must be able to have the Biomonitor 3 implanted. * Amyloid stage I-III patients with existing implantable cardiac devices such as pacemakers or defibrillators Exclusion Criteria: * Significant coronary artery disease \> 75% luminal stenosis in at least 1 epicardial vessel (by cardiac catheterization or coronary computed tomography), or history of myocardial infarction or coronary revascularization. * Congenital heart disease. * Pregnant patients * Patients whose heart failure is felt to be secondary to primary valvular disease (\>moderate/severe mitral regurgitation), uncorrected thyroid disease, obstructive or hypertrophic cardiomyopathy, pericardial disease or a systemic illness. * Absolute contraindications to cardiac MRI (such as renal failure with GFR\<30%). * Unwilling or unable to provide informed consent. * Patients with other life threatening diseases that would likely decrease their life expectancy over the next four years. * Patients who are post cardiac transplant. * Difficulty to attend the follow-up schedule due to a history of medical noncompliance, difficulty, or unwillingness to return to the study center for follow up. * Evidence of ongoing bacteremia or sepsis preventing implantation of a device * Unwilling or able to have the Biomonitor 3 interrogated