I was dx'd with 'complete heart failure' which seems to be triggered by what is suspected to be a hyperactive vagus nerve. I have a pacemaker to prevent my heart from stopping, I am still plagued with the symptoms triggered by my vagus nerve, such as car sickness. If I become car sick and cannot counteract the feelings quickly, I spiral into more severe symptoms (uncontrollable vomiting to the point of dehydration and an ER visit) resulting in the need for my pacemaker to assist because my heart rate drops too low. I am going to try these breathing techniques the next time I feel one of those episodes coming. I am doing everything I can to prevent these and continue an active life.