Table 2 Common Misdiagnoses of Disturbances Caused by ATTR Amyloidosis
Common Misdiagnosis | ATTR Symptoms Contradicting Given Diagnosis |
|---|---|
Cardiac | |
 Hypertrophic cardiomyopathy | Discordant voltage to mass ratio |
 Hypertensive heart disease | Discordant voltage to mass ratio; intolerance to beta blockers; waning need for antihypertensives |
 Undifferentiated heart failure with preserved ejection fraction | Nondilated hypertrophic LV |
 Uncomplicated degenerative aortic stenosis | Reduced longitudinal strain Frequent low-flow, low-gradient paradoxical pattern Thickened atrioventricular valves |
Neurologic | |
 Chronic inflammatory demyelinating polyneuropathy | Pain in the limbs, dysautonomia (erectile dysfunction, OH), symmetric polyneuropathy in upper limbs |
 Monoclonal gammopathy–associated neuropathy | Autonomic dysfunction (erectile dysfunction, OH) |
 Idiopathic axonal polyneuropathy | Dysautonomia (erectile dysfunction, OH), walking difficulties |
 CTS | Worsening of upper limb symptoms despite CTS surgery |
 Lumbar spinal stenosis | Failure to relieve symptoms in spite of spine surgery |
 Diabetic neuropathy | Walking difficulties |
 Amyotrophic lateral sclerosis | No upper motor neuron syndrome Reduction of amplitude of SNAP |
 Motor neuropathy | Reduction of amplitude of SNAP |
Gastrointestinal | |
 Inflammatory bowel syndrome | Absence of inflammation |
 Irritable bowel syndrome | Absence of or only minor abdominal pain; weight loss |
 Idiopathic diarrhea  Idiopathic bile acid malabsorption | Weight loss |
 Pseudo-obstruction | Absence of or only minor abdominal pain or radiologic findings of intestinal obstruction |