@remo Apart from prescriptions to help your kidneys to be more efficient (they are mildly inefficient due to the poorer blood supply that is typical with a heart in arrhythmia), or trying to be a bit more dehydrated than you really ought to be (meaning drinking less fluids), your best bet is to get your arrhythmia under control. That's with drugs, a pacemaker, or just a catheter ablation, depending on your local resources.