A Case of Quinine-Induced High Degree Complete Heart Block in a Young Teenage Nigerian Female

Background: Third-degree atrioventricular block occurs when atrial and ventricular activity are autonomous of each other.

Method: This is a case of a 17-year-old lady presenting to the emergency room of the University of Port-Harcourt Teaching Hospital, Rivers State with sudden onset chest tightness and syncope immediately following a dose of intravenous Quinine administration for treatment of malaria at a peripheral clinic. Vital signs on arrival revealed marked bradycardia with a pulse rate of 17 beats per minute with a blood pressure reading of 110/40mmhg. An urgent electrocardiogram done showed a third-degree Atrioventricular (AV) Block with a slow ventricular escape rhythm and complete AV dissociation. She was a previously healthy young teenager with no history of effort intolerance or cardiac disease. There was also no history of cardiac disease or sudden cardiac death in any first degree relative. Drug-induced AV block was diagnosed based on history, clinical presentation, and investigations.

Result: AV block is not uncommon with drug use however, but third-degree AV block is rarely caused by drugs. Quinine use for treatment of malaria should be reviewed due to this life-threatening side-effect especially in a region where centers for temporary pacing are not widely available nor affordable in Nigeria.

Conclusion: Cardiovascular monitoring is essential if Quinine administration is indicated for prompt identification and treatment of cardiac electrical disturbances.