Interventricular hydatid cyst with atrioventricular block: a case report.

Hydatid cyst in the heart is rare, occurring in about 3% of human echinococcosis. A 21-year-old woman was admitted to hospital with a third degree atrioventricular block. Echocardiography showed a cystic mass with a diameter of 2.5 cm within the interventricular septum. Serologic testing for Echinococcus was clearly positive, and hence cardiac surgery was planned. Sterilization of the cystic cavity was achieved by injecting formaldehyde solution in the cavity before cystectomy. Definitive pacemaker implantation was necessary before discharge. Cardiac hydatid cysts constitute an indication for surgery which is necessary to prevent potentially lethal complications such as cystic rupture with embolic phenomena and anaphylactic shock.