Extreme Drop in BP and HR 1 Min after Stress Test

[R_WAGNER]

Hello. I am a 26 year old female, normal weight (5'5" 120 lbs), and have been experiencing frequent episodes of tachycardia which is often accompanied by feeling light-headed/dizzy, numb extremities, and sometimes high BP (especially diastolic). For these reasons, I received an ECHO and stress test (treadmill) today. Preliminary ECHO results looked good. Also, stress test was going great until very end (docs said EKG was looking great). My HR got up to 190 (target was 194) and my legs were getting very tired and my chest was getting tight, so I let the nurse know this. She said can you go another 30 seconds, and I said yes (I am not big on giving up). I made it the 30 seconds then partially collapsed. My vision was blurry/black, I started hyperventilating, my hearing was really weird (everyone felt like they were miles and miles away), I was incredibly nauseous, and certain I was going to pass out. They laid me down on the exam table and had me breathe into a paper bag. They said 1 minute after exercise my BP dropped to 80/60 and my heart rate went from 180s to 78. All within 1 minute. They said dramatic and rapid decrease was abnormal, referred to this as "syncope" and promptly scheduled me for a tilt table test. I was just wondering if anyone had any insight/comments about this extreme/rapid drop in BP and HR immediately following the termination of my stress test. I greatly appreciate your time.

[CCFHeartMD 12]

It would be important to know what type of rhythm occurred at the time of the abrupt HR drop (190 to 78 bpm).  If your rhythm was sinus (normal conduction), the approach would be different than if it were some sort of heart block.  IF this event occurred during exercise test, I assume you had EKG monitoring, and the doctors would be able to judge exactly what type of rhythm you were in.  Regarding your initial symptoms of fast hearbeats, lightheadedness and numb extremities... I think it sounds like some kind of POTS (postural orthostatic tachycardia syndrome) - spectrum disorder.  I recommend a tilt table test to better evaluate this.

[R_WAGNER]

Thank you, Dr., for your response. My cardiologist canceled the Tilt Table Test and diagnosed me with inappropriate sinus tachycardia. Says my EKG showed normal rhythyms while at rest and during exertion, just more rapid than normal for both. Said ECHO looked good, other than signs of mild diastolic dysfunction, likely due to the heart not having enough time to completely fill with flood before it beats due to beating so rapidly. He said "he did not know what to make of the pre-syncope after the stress test." which was a bit concerning. Did not prescribe me anything other than Yoga 3 times per week; is wanting to take a "wait and see" approach. I am hoping this is the right course of action. Please let me know if you have any thoughts on this diagnosis/treatment approach. I am open to seeing another doctor for a second opinion; I want to be proactive and ensure I am doing the right things for my health.

[R_WAGNER]

I wanted to add that I have had my thyroid and catecholamines tested; all were within normal ranges. My plasma renin activity and aldosterone were both high (9.6 ng and 40 ng, respectively). Thank you for your time and assistance.