title: Ventricular pacing from the middle cardiac vein mimicking supraventricular morphology.
abstract: A case is described in which ventricular pacing from the middle cardiac vein produced an electrocardiographic pattern which mimicked the morphology of the normally conducted beats. The possible etiologies of this unusual phenomenon and its implications concerning the functional anatomy of the normal conduction system in the human heart are discussed.
mesh_terms: D000368:Aged; D002037:Bundle-Branch Block / Q000209:etiology; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D003331:Coronary Vessels / Q000502:physiology*; D004567:Electrodes, Implanted; D006329:Heart Conduction System / Q000502:physiology; D006801:Humans; D008297:Male