Hi - I am a 36-year old female who has experienced a faster than normal pulse and some exercise intolerance for as long as I can remember. For many years, I just brushed this off and none of my physicians flagged it as a cause for concern. I even had a healthy, full-term pregnancy with no cardiac complications.
A few weeks ago, I noticed my heart rate increasing to a level that made me very anxious. I ended up in the ER, and an EKG indicated a pulse of 145 BPM. I was admitted overnight, and received a chest CT scan, echocardiogram and complete blood panel. Everything was normal, and my heart remained in sinus rhythm the entire time.
I've since been referred to a cardiologist, and I'm awaiting the results of a 24-hour holter monitor. During my first and only appointment to date (EKG in the office read 112), my cardiologist told me that beta blockers would not do any good - and that I should drink liters of water and exercise for at least 30 minutes daily. She thinks I am simply deconditioned. Inappropriate sinus tachycardia was not specifically mentioned, but my condition sounds much like the descriptions I've read of it online.
1. With IST, would I have a heart rate of 75-85 while sitting relaxing at night - or are those numbers "too low"?
2. When I was in the ER, the doctors asked me to try a few vagal maneuvers to lower my heart rate. If I had IST, would these vagal maneuvers actually be successful?
3. If I do, in fact, have IST, what would be the risks in my having a second pregnancy? I'm not so much worried about being uncomfortable - as I know that pulse naturally increases during this time. I'm more worried about my symptoms worsening on a permanent basis or developing a cardiomyopathy.
Any insight or advice would be much appreciated!