Reversible Cold Block of the Specialized Cardiac Tissues of the Unanesthetized Dog

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Science  14 Aug 1964:
Vol. 145, Issue 3633, pp. 723-725
DOI: 10.1126/science.145.3633.723


The sinoatrial node and the bundle of His in intact, unanesthetized dogs were subjected to local cooling by means of surgically implanted devices. Impulse formation in the sinoatrial node could thus be suppressed at will and the heart rate regulated within a physiological range by an electrode driving the atrium. Reversible blockage of atrioventricular conduction was easily induced on cooling the region of the bundle of His.