What are the best positions to sleep with postural orthostatic tachycardia syndrome?

It does not matter. It is only matter when you wake up and getting out of the bed then you should do it very slowly. Take care.

Some clinicians advocate raising the head of the bed over 6 inches so your heart is higher than your abdomen. Lying in your left side is better for your airway & for brain reprocessing while asleep&cool environment is better than a hot one are some other suggestions.