Epinephrine‐Induced Ventricular Premature Complexes Due to Early Afterdepolarizations and Effects of Verapamil and Propranolol in a Patient with Congenital Long QT Syndrome

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Abstract
Epinephrine‐Induced VPCs and EADs in Congenital LQTS. We report a patient with congenital long QT syndrome in whom early afterdcpolarizations (RAl)s) were demonstrated on monophasic action potential (MAP) recordings in the left ventricular mid‐base inferior wall. Epinephrine infusion at 5 fig/mm increased the amplitude of the EADs and the late component of the T(U) wave. Epinephrine also induced ventricular premature complexes (VPCs) with right hundle branch block morphology and left‐axis deviation that occurred from the peak of the EADs. Verapamil injection (5 nig) during continuous epinephrine infusion abolished all VPCs with a slight reduction in the amplitude of the EADs. Propranolol injection (5 mg) in addition to verapamil further reduced the amplitude of the EADs and the late component of the T(U) wave. These findings suggest that the epinephrinc‐induced VPCs were closely related to triggered rhythm arising from the EADs, and that both verapumil and propranoloi were effective for the suppression of VPCs and EADs.