According to research, POTS is a state of chronic hypocapnia, low blood CO2 levels, as a result of hyperventilation. Diamox (by inhibiting carbonic anhydrase, which breaks down CO2 into carbonic acid) increases blood CO2 levels.
Thanks for sharing, I always wondered how Diamox might affect people with POTS. I think one explanation of what might be happening is that the symptoms of POTS are a result of a lack of oxygen reaching the brain. Carbon dioxide is required for oxygen to enter the cell, so perhaps the Diamox is allowing the brain to get the oxygen it needs, but isn't correcting the issue that causes the orthostatic tachycardia in the first place, hence the lack of symptoms even in the presence of a high heart rate.