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. You should know that this bubbling sensation has to do with a rhythm issue. There are some electrical impulses that generates in some part of the heart different from normal sinus rhythm.They cause a premature heart contaction that its not a normal one. It might be just an extra sistolic beat or a chaotic arythmia. In this cases you might experience palpitation, flattering or bubble sensation, anxiety, difficulties in breathing deeply, dizziness ect. There might be different causes of this rhythm issue like simple stress, coffee and alcohol consumption or pathologys like anemia, hyperthyroidism or electrolyte imbalance. So, if I was your treating doctor I will recommend some examination like an electrocardiogram, a cardiac echo to evaluate heart function and walls, a full blood analyze to exclude anemia, hyperthyroidism and of course a holter rhythm monitoring to evaluate your rhythm tendency. Only after this we can better understand what we are dealling whith and how to treat it. Hope I was helpfull. Best regards Dr.Ervina.