I am a 35 y/o female with a history of papillary thyroid cancer (1995) and am on thyroid hormone. My most recent TSH was 1.8 (normal range, not suppressed). Back in Nov 1998, I had a 10-day period of having a rapid heart rate (140 bpm) while standing. When sitting or reclining, my heart rate was normal. Any normal activity was very tiresome. I had an EKG, event monitor, and echocardiogram done. All studies were normal with the exception of noted tachycardia at times. My cardiologist also stated that I had a VERY mild prolapse. It was so mild, he hesitated to even mention it and was still called my echo "normal." This situation resolved itself and since that time I have had brief episodes of rapid heart rate, usually no higher than 120. It mostly occurs in the morning and is never really bothersome. I also note that it occurs sometimes after a meal of fatty foods. I do also have mild reflux and take Prilosec. Just this past week, I noticed a return of the heart rate. Again, it never really got above 120, but when it was happening I was in a situation where I felt anxious so I thought that was contributing. As this week progressed I noticed it was continuing. Short walks that a normal take a work left me mildly short of breath and the heart was pounding. Unfortunately, also occuring was a very stressful event and now, this morning, my "standing" heart rate is easily 140 bpm. I vacuumed my family room and felt like I was doing aerobics. I just took some Inderal to counteract it and it has helped but left me sleepy. Can a generalized anxiety situation or disorder cause extended periods of elevated heart rate?? I know panic attacks will cause rapid heart rate but it seems for short rates of time. I am not experiecing panic feelings. I do go through periods of mild anxiety. What role does being in the upright position have to do with this? My heart rate is always quite normal (70-85) while resting. My thyroid levels are always normal so I can't blame the medication. Any ideas?
Thank you for your question. There are many causes of tachycardia (fast heart beat) and they can be divided roughly into sinus (originating from the sinus node or heart's natural pacemaker) and non-sinus tachycardias. Nonsinus tachycardias are either supraventricular (coming from the upper chambers of the heart) or ventricular (coming from the lower chambers of the heart). Supraventricular tachycardias include: paroxysmal supraventricular tachycardia, atrial flutter, atrial fibrillation and AV nodal tachycardia. Ventricular tachycardias are more serious in nature and are due to a rapid depolarization of the ventricles.
Sinus tachycardia is defined as a heart rate of greater than 100 beats per minute originating from the sinus node. Sinus tachycardia is classified as either appropriate or inappropriate. There are many causes of appropriate sinus tachycardia such as exercise dehydration, deconditioning, volume loss due to bleeding or other loss of body fluids, hyperthyroidism, and electrolyte abnormalities. Panic attacks and anxiety can elevate the heart rate but other conditions should be ruled out first.
The Content on this Site is presented in a summary fashion, and is intended to be used for educational and entertainment purposes only. It is not intended to be and should not be interpreted as medical advice or a diagnosis of any health or fitness problem, condition or disease; or a recommendation for a specific test, doctor, care provider, procedure, treatment plan, product, or course of action. MedHelp is not a medical or healthcare provider and your use of this Site does not create a doctor / patient relationship. We disclaim all responsibility for the professional qualifications and licensing of, and services provided by, any physician or other health providers posting on or otherwise referred to on this Site and/or any Third Party Site. Never disregard the medical advice of your physician or health professional, or delay in seeking such advice, because of something you read on this Site. We offer this Site AS IS and without any warranties. By using this Site you agree to the following Terms and Conditions. If you think you may have a medical emergency, call your physician or 911 immediately.