Well, I'm just passing along an interesting method of resolving SVT. It was somewhat unusual. Called to a clinic to help a patient with a "quivery" feeling. The heart rate was between 150 and 160. The patient had lots of other issues in her history, including liver disease and varices in the esophagus and in the intestines. The normal Valsalva maneuver was not possible due to the concern for internal bleeding. The rate was borderline SVT, and since no cause was easily determined, it was classified PSVT, but it had continued for an hour prior to EMS. SPO2 was 93. SPCO2 was 26. BG was normal, Hemoglobin was within normal limits, no blood in the urine. IV established. 12-lead obtained with monitor verifying SVT. The patient was asked to scootch (sp) over from the cllnic bed to the ambulance cot. The patient grunted twice during this move to the cot. We watched the heart rate resolve to NSR after the second grunt. This was not taught as part of ACLS that I am aware of. Of course we transported the patient for follow up care and further diagnosis, but I had never heard of a grunt resolving SVT before, had you?