Circadian rhythm of blood pressure reflects the severity of cardiac impairment in familial amyloid polyneuropathy

SummaryBackgroundCardiac amyloidosis due to familial amyloid polyneuropathy (FAP) includes restrictive cardiomyopathy, thickened cardiac walls, conduction disorders and cardiac denervation. Impaired blood pressure variability has been documented in FAP related to the Val30Met mutation.AimsTo document blood pressure variability in FAP patients with various mutation types and its relationship to the severity of cardiac involvement.MethodsBlood pressure variability was analysed in 49 consecutive FAP patients and was compared with a matched control population. Cardiac evaluation included echocardiography, right heart catheterization, electrophysiological study, Holter electrocardiogram and metaiodobenzylguanidine (MIBG) scintigraphy.ResultsA non-dipping pattern was found in 80% of FAP patients and in 35% of control patients (P<0.0001); this was due to a significantly lower diurnal blood pressure in FAP patients (FAP group, 113±21mmHg; control group, 124±8mmHg; P