Extensive Intraventricular Conduction Defect

Destruction of the entire canine right ventricular Purkinje-net system, by the introduction of dilute Lugol's solution into the right ventricular cavity, results in an intraventricular conduction defect which is 20 to 30 msec. greater in duration than that of right bundle-branch block. The mode of right ventricular surface activation is altered. A characteristic electrocardiographic and vectorcardiographic pattern is produced. Histological studies confirmed the absence of Purkinje-net cells in animals with chronic block.