Aim of the study: To assess the cardiac involvement of familial amyloidotic polyneuropathy--Portuguese type (FAP) in a prospective study.
Introduction: FAP is a sensitive, motor and autonomic familial polyneuropathy, due to amyloid deposits on nerve and vascular structures, related to abnormal transthyretin synthesis. FAP is a progressive systemic disease. The associated cardiomyopathy is well characterized in the Japanese form, but studies on FAP--Portuguese type cardiomyopathy remains controversial, regarding its occurrence and clinical and morphofunctional aspects.
Population: The Authors studied 60 Portuguese caucasoid patients, belonging to 55 different families: 23 women from 27 to 67 years old (m = 40.78 +/- 18.4) and 37 men, from 31 to 60 years old (m = 40.8 +/- 12.8). The diagnosis was established by characteristic clinical aspects, electromyograms and nerve or gut biopsies, positive for amyloid. Patients were classified in phases from I to VI according to the severity of neurological involvement and disability.
Methods: All the patients carried out clinical evaluation, thorax X-Ray, conventional EKG, Holter EKG (20-24 hours), M + 2D echocardiography and phonocardiography. Morphological and functional data were obtained from 85 echocardiographic recordings; special attention was paid to the evidence of structural abnormalities, evaluation of internal chamber dimension, left ventricular mass and systolic function indexes (left ventricular fractional shortening, left ventricular ejection fraction, left ventricular end-systolic stress index and Vcf).
Conclusions: Suggestive aspects of pericardial and myocardial amyloid infiltration were found even in the earliest phases of the disease; all the records of patients in advanced phases (III to VI) were abnormal. The most frequent abnormalities founded were: a bright sparkling pericardial and myocardial echo pattern and increased ventricular wall thickness, with increased left ventricular mass index in 85% of patients in phases III to VI. Vcf was abnormally increased when plotted together with left ventricular end-systolic stress index, which was normal or decreased, probably reflecting "excessive" inotropism, in 1/3 of patients in phases III to VI. Systolic function was never depressed; no cardiac chamber enlarged. So, this study points out the presence of an infiltrative and/or hypertrophic cardiomyopathy in FAP--Portuguese type; suggestive aspects of diastolic dysfunction and decrease in systolic function were recorded. However, in the clinical setting of FAP, symptoms and signs like dyspnea, fatigue, oedema, may not be diagnosis of congestive heart disease.