Abstract: A medical lead adaptor that provides a rapid, secure, insulated connection of the lead connector end assembly of one or more implantable cardiac lead with an external medical device is disclosed. The adaptor connector assembly is configured with an elongated bipolar receptacle to accept a bipolar, in-line, or a unipolar lead connector end having common dimensions and with connector pin and ring, bipolar receptacle contacts spaced apart from one another therein. An elongated slot that extends laterally to an adaptor connector assembly exterior surface allows the lateral insertion of a stylet wire into the elongated bipolar receptacle. A separate pair of positive and negative polarity unipolar receptacles are provided for receiving unipolar medical lead connector pins and making electrical and mechanical contact with unipolar receptacle contacts therein.