An apparatus and method for conferring a therapeutic current to the heart is provided. The apparatus includes a first electrode, a second electrode, a current generator and a controller. The apparatus may further include a sensor. The sensor is generally configured to measure field strength between the first and second electrode. The sensor may also monitor the cardiac cycle. The method includes applying an electric stimulus to the heart and sensing the electric field generated by the electric stimulus to prevent the level of current from inducing unwanted depolarization.