Humans; Cardiac Pacing, Artificial/methods; Heart Block/classification; Pacemaker, Artificial/standards; Cardiac Pacing, Artificial/history; Heart Block/complications; Heart Block/epidemiology; Heart Block/physiopathology; Pacemaker, Artificial; Prostheses and Implants; Intraoperative Complications/diagnosis; Intraoperative Complications/epidemiology; Intraoperative Complications/therapy; Postoperative Complications/diagnosis; Postoperative Complications/epidemiology; Postoperative Complications/therapy; Preoperative Care/methods; Intraoperative Care/methods; Postoperative Care/methods; Monitoring, Physiologic/instrumentation; Monitoring, Physiologic/methods; Monitoring, Physiologic/standards; Anesthesia, General/methods; Anesthesia, Intravenous/adverse effects; Anesthesia, Intravenous/methods; Neuroleptanalgesia/adverse effects; Neuroleptanalgesia/methods