A N Farkas1, M Marcott2, J H Yanta1, A F Pizon1. 1. Division of Medical Toxicology, Department of Emergency Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. 2. University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Abstract
WHAT IS KNOWN AND OBJECTIVE: Toxic prolongation of the QRS interval most often results from blockade of cardiac voltage-gated sodium channels and manifests on electrocardiogram with a right bundle-branch block-like morphology. Rarely, a left bundle-branch block (LBBB) morphology has been reported. CASE REPORT: We report a case of transient LBBB resultant from ingestion of lamotrigine and citalopram which was refractory to sodium bicarbonate therapy and eventually resolved spontaneously. WHAT IS NEW AND CONCLUSION: Cases of toxic LBBB are less likely to respond to bicarbonate therapy, suggesting that this finding is due to a mechanism other than sodium channel blockade.
WHAT IS KNOWN AND OBJECTIVE: Toxic prolongation of the QRS interval most often results from blockade of cardiac voltage-gated sodium channels and manifests on electrocardiogram with a right bundle-branch block-like morphology. Rarely, a left bundle-branch block (LBBB) morphology has been reported. CASE REPORT: We report a case of transient LBBB resultant from ingestion of lamotrigine and citalopram which was refractory to sodium bicarbonate therapy and eventually resolved spontaneously. WHAT IS NEW AND CONCLUSION: Cases of toxic LBBB are less likely to respond to bicarbonate therapy, suggesting that this finding is due to a mechanism other than sodium channel blockade.