Third-degree atrioventricular block in a patient under chloroquine therapy
Guedira, N.; Hajjaj-Hassouni, N.; Srairi, J.E.; el Hassani, S.; Fellat, R.; Benomar, M.
Revue du Rhumatisme 65(1): 58-62
1998
ISSN/ISBN: 1169-8446 PMID: 9523387 Document Number: 492526
The case is reported of a 43-year-old woman who developed juvenile chronic arthritis at the age of 10, followed in adulthood by seropositive rheumatoid arthritis. In 1980 she was put under chloroquine sulfate at a dose of 200 mg/day (152.66 mg of chloroquine), with 10 mg/day of prednisone. She developed myalgia and increased skin pigmentation, but disregarded recommendations that these symptoms required discontinuation of chloroquine therapy. She was lost to follow-up, but continued the chloroquine therapy of her own accord. In December 1993, she developed a 3rd-degree atrioventricular block with syncopes requiring implantation of a pacemaker. The rare but well-documented myopathy induced by antimalarial agents can produce early severe lesions of the cardiac muscle, which may have a predilection for the interventricular septum, explaining the risk of atrioventricular block. Although histological studies were not performed in this case, the clinical evidence of toxicity, absence of underlying heart disease and fairly young age of the patient indicated chloroquine toxicity. Periodic cardiac investigations including electrocardiography may be warranted in patients undergoing antimalarial therapy.