This may fall under the same heading as scaring someone to cure their hiccups. A Queens man's racing heartbeat got an unexpected fix during a routine exam. The 29-year-old arrived at the hospital one night with his heart beating at 140 beats per minute, and an EKG quickly showed he was in atrial fibrillation, a common arrhythmia where the heart's upper and lower chambers fall out of sync. Before starting standard treatment, the attending doctor needed to check for internal bleeding and did so by using his finger to deliver a quick exam “around back.”
To everyone's surprise, the procedure slowed the patient's heart to 80 beats per minute and eliminated the arrhythmia entirely, a result that held up months later at a follow-up. Doctors theorize that the exam, combined with a Valsalva maneuver breathing exercise that the patient was instructed to perform at the same time, stimulated the vagus nerve, which runs from the brain through the gut and heart and helps regulate the body's rest-and-relaxation response. More research is needed before anyone suggests the approach as a substitute for medication or cardioversion, so don’t work this into your CPR routine quite yet.
Source: NY Post