My father (69yo) suffer from AF (atrial fibrilliation)- doctors say etiology is unknown in this case. He has low blood pressure and low heart rate during casual days, exept of course when he has AF. AF takes usually several hours (over 200 beats/minute) and comes sometimes without any reason (sometimes the reason is high temperature- weather, being tired after some work in garden, being in room where is stiflingly). He takes medications to prevent himself from AF but they don't work. 6 doctors tried without result to determine the etiology and choose the right medicaments on basis of different tests (incl. Holter, Echo, morphology, hormons of thyroid, potasium and magnezium). The problem is that some medicaments which doctors would like to prescribe him he cannot take because he has normally low heart rate and low blood pressure and the medicaments would make it unacceptably too low. I would be gratefull for any advice on medicaments and therapy for person with low heart rate and blood pressure who suffer from AF.