Characterization of Autonomic Dysfunction in AL Cardiac Amyloidosis: A Moroccan Case Series Study

Abstract

Cardiac amyloidosis is a rare but serious manifestation of systemic amyloidosis, presenting diagnostic and therapeutic challenges. The AL subtype is the most common, though transthyretin-related forms are increasingly recognized due to population aging. One frequent complication is autonomic dysfunction, resulting from impaired autonomic nervous system regulation. Aims: This study aims to explore autonomic dysfunction in patients with AL cardiac amyloidosis and evaluate the clinical implications through specific autonomic tests. Study Design: Cross-sectional descriptive and analytical case series. Place and Duration of Study: Cardiology Department, CHU Ibn Rochd, Casablanca, Morocco; from March 2021 to June 2023. Methodology: Ten patients diagnosed with AL cardiac amyloidosis were included. Diagnosis was based on clinical, biochemical, histological, and imaging criteria. Autonomic function was evaluated using standardized non-invasive tests: deep breathing, isometric handgrip (15s and 3 min), mental stress, and active orthostatic tests. The results were classified using established criteria to identify vagal deficiency, sympathetic dysfunction, and baroreflex impairment.. Results: Autonomic dysfunction was identified in 70% of patients. Vagal deficiency was present in 60%, and 40% showed combined sympathetic and parasympathetic failure. Diverse dysautonomic syndromes were observed: severe sympathetic-parasympathetic denervation, sympathetic hyperactivity with vagal impairment, baroreflex abnormalities, and isolated vagal or sympathetic involvement. Clinical manifestations included orthostatic intolerance, cardiovascular symptoms, and vasomotor disturbances. Conclusion: Autonomic dysfunction is frequent and clinically significant in AL cardiac amyloidosis. A structured evaluation is essential for optimizing patient management and improving quality of life.