Clinical Investigations of Autonomic Heart Regulation and Renal Function of Familial Amyloidotic Polyneuropathy

Abstract

Familial amyloidotic polyneuropathy (FAP) is a systemic disease and its main symptoms are polyneuropathy and autonomic dysfunction. Stokes-Adams syndrome and renal involvements can be the cause of death.

The effects of atropine and isoproterenol on the cardiac conduction sytem in FAP were studied using surface ECG and His bundle electrograms. Intravenous administration of 1 mg atropine sulfate induced prolongation of the sinus cycle length and sinus node recovery time, but isoproterenol shortened the conduction system. The therapeutic doses of atropine may be potentially detrimental for conduction blocks in FAP, but isoproterenol may have beneficial effects.

For the quantitative and non-invasive measurements of the autonomic dysfunction in FAP, a coefficient of variation (CV) of R-R intervals in ECG was investigated, and compared to the age-matched normal controls. The mean of CV was significantly decreased in FAP in their 30′s and 40′s. This examination is a valuable method for detecting early involvement of the autonomic dysfunction of the heart.

The renal function was investigated in 23 cases of FAP. Patients were classified into four stages according to the degree of their ADL and the degree of sensory impairment. Proteinuria was noted in the early stage, and creatinine clearance was most closely related to the disease progress.