Inclusion Criteria:  Ambulatory adults age ≥65 years with TTR-cardiac amyloidosis (confirmed by PYP scan or biopsy) Taking beta-blocker  Exclusion Criteria:  Alternate causes of HFpEF Syndrome:  Severe aortic stenosis and mitral stenosis Constrictive pericarditis High Output HF  Other compelling indication beta-blocker  Hypertrophic cardiomyopathy Angina symptoms Acute coronary syndrome, myocardial infraction or coronary artery bypass surgery in prior 3 years Atrial arrhythmia with hospitalization for rapid ventricular response, prior 1 year Sinus tachycardia >100 bpm, atrial arrhythmia with ventricular rate >90 beats per minute, systolic blood pressure >160 mmHg  Clinical instability (N-of-1 trials are appropriate for stable conditions only)  Decompensated heart failure Hospitalized in past 30 days Medication changes or procedures in prior 14 days that could confound observations, per PI discretion Estimated life expectancy <6 months Moderate-severe dementia or psychiatric disorder precluding informed consent Any condition that, in Principal Investigator's opinion, makes the patient unsuitable for study participation