Tachycardia and PVCs - Fast Heart Rate and Palpitations

Tachycardia is a fast heart rate. Normal resting heart rates for adults range between 60 to 100 beats per minute. Tachycardia occurs when your resting heart rate is above normal. Palpitations are irregular heart beats. There are several different types of palpitations, depending on what causes them as well as when and where they occur in the heart. I have personally dealt with what are known as PVCs or premature ventricular contractions. These occur when the ventricle contracts before the atrium, causing your heart beat to be out of order. For me, this feels like a fluttering in my chest. When you are having PVCs, your heart tries to reset itself to beat normal again. When this happens, I feel a hard beat or thump like my heart is jumping in my chest. Both tachycardia and palpitations can come and go or be continual and may or may not interfere with your normal activities.

Tachycardia and Palpitations Caused By Thyroid Medication

I first noticed having problems with a fast heart rate and palpitations when a doctor had me on too high of a dose of thyroid hormone replacement medication. I actually ended up in the hospital for three days from being over medicated. My resting heart rate wouldn't stay below 100 beats per minute and I was put on beta blockers for the first time. Once my heart rate was under control, I was allowed to go home. I was kept on the beta blockers and off of thyroid medication for the next month to bring my thyroid levels back down to normal. I was then slowly weaned off of the beta blockers.

Episodes of a Racing Heart

I did well for a month or so. Then I started to have episodes of my heart racing over 140 beats per minute while resting. I was also having palpitations and pain in my chest and down my left arm. The episodes would last ten to fifteen minutes to over an hour and would make me feel weak and out of breath. I was unable to go about my normal activities during an episode and would be exhausted for hours or even the rest of the day after one. I continued having problems with these episodes and had several trips to the emergency room. Unfortunately, they could never catch my heart racing and I was always sent home, often being treated like there was nothing wrong with me or that I was making a big deal out of heartburn or acid reflux.

Tachycardia and High Blood Pressure Found and Treated

I continued to get worse with daily episodes of tachycardia and PVCs with chest pain until it became almost continual and very debilitating. I once again took a trip to the emergency room. This time my heart was still racing and my blood pressure was up while I was being examined. The doctor had a beta blocker pumped into my IV to bring my heart rate and blood pressure down. It was also found that my magnesium levels were low. I was allowed to go home, but was given prescriptions for magnesium and a beta blocker along with the number to a cardiologist that I needed to see. The beta blocker helped some, but not enough and it wore off quickly. At my first appointment with the cardiologist my heart rate and blood pressure were still too high, so he quadrupled the dose by doubling the amount and having me take it twice a day instead of once.

Continued Problems with Tachycardia and PVCs

Even after being put on a higher dose of medication, I continued to have regular problems with tachycardia and PVCs with chest pain. I ended up in the emergency room again. This time the PVCs were caught. My cardiologist was very concerned that I might have heart damage from when I was over medicated on thyroid medication. He ordered a bunch of heart tests to be done. I had a cardiac stress test, an ultrasound of my heart, and a cardiac myoview scan done. None of the tests showed any damage and my cardiologist was relieved, but I continued to have problems with tachycardia and PVCs. My cardiologist then ordered a 24 hour holter heart monitor. This only showed a little of what was going on, so my doctor ordered a 30 day King of Hearts monitor. This caught many episodes of my heart racing and having palpitations, but it also showed that there wasn't anything actually wrong with my heart. My cardiologist was very glad there wasn't anything wrong with my heart. He said my heart itself was very healthy and he wasn't sure what was causing the tachycardia and palpitations.

A Longer Lasting Beta Blocker Made a World of Difference

After a while, the episodes of tachycardia and PVCs occurred less often. I did well for several months. Then the beta blockers didn't seem to be lasting long enough any more and I started having problems with my heart rate being high almost every day along with PVCs and chest pain again. I let my cardiologist know that the medication didn't seem to be lasting long enough and he switched me to an extended release beta blocker. Though the medication is supposed to last 24 hours, my body metabolizes it quickly and I have to take it twice a day. After being on the extended release beta blocker for a few weeks, my heart was back under control. Since being on the extended release beta blocker, I haven't had as many problems with a fast heart rate, palpitations, or chest pain. The cause of these problems may not be completely clear, but I am glad they are under control.

Further Reading

Thyroid Hormone Replacement: Signs and Symptoms of Overmedication (Overdose)

Sources

MedicineNet.com

MayoClinic.com