Complete atrioventricular block with diastolic mitral regurgitation due to severe lithium intoxication. A case report

Abstract

Background Lithium remains the first line therapy for treatment of bipolar disorder and is widely used in psychiatry despite its narrow therapeutic window. Cardiac side effects are uncommon, but when they are present, they can vary from benign repolarization changes to life threatening tachyarrhythmias as well as conduction time abnormalities. In extremely rare cases complete atrioventricular block with cardiogenic shock can be seen. Methods We report the clinical course and outcome of a 79-year-old patient who presented with bradyarrhythmias and a complete atrioventricular block due to severe lithium intoxication. The patient was admitted to ICU where fluid resuscitation and intermittent haemodialysis were performed. Interestingly, the cardiac ultrasound on ICU showed a diastolic mitral regurgitation which was related to the underlying complete atrioventricular block. Results After two cycles of haemodialysis lithium blood levels were normalised and 24 h later sinus rhythm was restored without any signs of atrioventricular block. The patient recovered completely. Conclusion Lithium is widely used for the treatment of bipolar disorder and it can rarely lead to complete atrioventricular block. If the physician encounters a patient with a history of lithium use, who also shows cardiac arrhythmias, then lithium intoxication should always be ruled out. Haemodialysis is the treatment of choice in severe lithium intoxication. Diastolic mitral regurgitation can hint towards underlying atrioventricular conduction disturbances.