Cardio-pulmonary function in familial amyloidosis with polyneuropathy : a clinical study of cases from northern Sweden

Sammanfattning: Familial amyloidosis with polyneuropathy (FAP) was first reported from Portugal in 1952, but since then this syndrome has been recognized in many countries including Sweden. In this investigation cardiac and pulmonary functions in the Swedish variety of FAP were studied.A retrospective survey of the ECG findings in 71 patients showed a high prevalence of atrioventricular (38%) and intraventricular (41%) conduction defects, and also a high prevalence of atrial fibrillation (14%). In several patients a progression in the conduction defects to advanced disturbances could be observed and 10 out of 71 patients (14%) in the present series required pacemaker treatment.A histopathological study of the atrioventricular part of the conduction system showed marked amyloid infiltration in each case, which may explain the high prevalence of conduction defects.In an échocardiographie study which emcompassed 22 consecutive patients, all but those two patients with the shortest duration of symptomatic disease showed abnormal features. The most frequent and characteristic findings were hypertrophy of the interventricular septum (86%) and a hyperrefractile appearance of the iryocardium (68%). This unusual association of échocardiographie features is considered almost diagnostic of cardiac amyloidosis.A hemodynamic study showed an essentially normal systolic heart function, but in several patients there were signs of impaired diastolic function with increased myocardial rigidity. Several patients showed signs of obstruction of the ventricular outflow tracts. This finding, as well as the échocardiographie features, is in accordance with altered anatomical and functional properties of the interventricular septum.The major pulmonary function abnormalities were decreased maximum respiratory pressure which indicate that the neuropathy in FAP involves the respiratory musculature, and impaired diffusing capacity consistent with an alveo-capillary block caused by amyloid deposits.