Hello, Welcome to Just Answer and thanks for your question. As you know from your research, the vagus nerve wanders through many parts of the body. When stimulated, its effect on the heart is to slow the heart down and lower blood pressure which can lead to fainting with or without AV block. Anything can stimulate the vagus nerve anywhere along its path. Sometimes it is GI problems (so-called "stomach flu", cholecystitis), carotid sinus massage, pain or the fear of pain, emotional stress, seeing something horrible like an auto accident. There is a report in the literature of a woman who became near-syncopal whenever she ate a sandwich. The swallowing was enough to hyperstimulate the vagus nerve causing the drop in heart rate and blood pressure that left her near-fainting.