Abstract: An electrode for transcutaneously delivering defibrillation pulses to a patient's heart. The electrode comprises an insulating substrate, a conducting plate which is positioned on the substrate and which has an electrical terminal for making a connection to an external source of electrical current, and a layer of electrolytic gel covering the entire top surface of the conducting plate. This gel contacts a patient's skin when the electrode is positioned on the skin to prevent the conducting plate from contacting the skin. The gel comprises a concentration of an electrolyte such that the combination series resistance of two of the electrodes, when measured with the electrodes configured in a series circuit with a 50 .OMEGA. resistance, and with the electrolytic gel layer of each electrode in contact with that of the other electrode, is greater than 1 .OMEGA. when a 200 Joule defibrillation pulse is discharged into the series circuit.