Hello and thank you for using HCM.I carefully read your question and I understand your concern. I will try to explain you something and give you my opinion. I think that in your mothers case we have to do with a rhythm issue. There are some pathologyes of the electrical system of the heart that causes in the same time fast heart beats and heart electrical pauses. This pauses means that the heart electrical impulse fails for some seconds to generate a normal impulse or contraction. This leads to a pause making the person to loose senses or what we call syncope. Sometimes it is difficult to diagnose this patologyes.The patient might experience fast heart beats,treating them whith medication that might aggravate the situation and lead to syncope. So,in my opinion this is not a blood pressure issue but a rhythm one.Of course long heart pauses lead to secondary hypotension. So if I was your treating doctor and we are dealing with a histori of losing senses and fast heart beat I will recommend some examination like an electrocardiogram, a cardiac echo to evaluate heart function and valves and a holter rhythm monitoring. Through this process we can better judge what happens to your rhythm and how to menage it. Hope I was helpful.Wish your mother good health. Best regards.