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Dr. Saha
Dr. Saha, Doctor (MD)
Category: Health
Satisfied Customers: 17657
Experience:  35 years of experience
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I woke last night and my heart was really beating fast

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I woke last night and my heart was really beating fast. I timed it and it peaked at around 120 and never fell below 100 bpm. This went on for the rest of the night causing me to lay there in a state of heightened anxiety. What causes this to happen? As I was in bed there was no activity to account for this increase in heart rate. Is it dangerous? I had an ECG a couple of months ago plus a thorough exam with a stethoscope and was assured all was well. But can this diagnosis be correct? I also experience skipped beats from time to time but there was no experience of this last night.
I became concerned at the re-occurence of these symptoms after many years and am determined to get to the root cause so I have been reading all I can about the problems and have even invested in a stethoscope as I want to HEAR what's happening. (Hope you don't think that's too weird!). Whan I am lying on my left side using the diaphragm I can hear a sound in between S1 and S2 especially when the rate is fast. This could be a mid-systolic click from what I have read and heard on demo soundtracks on the web, but how come my doctor didn't pick up on this? There is no actual pain as such but sometimes when I am out on my bike I experience a dull ache which disappears quite soon after I stop.

Possible causes of increased heart rate can be anxiety, hyperthyroidism,
caffeine, drugs, heart disease etc.

When doctor has examined, the increased might not have been present at that time.

As you have felt the symptoms again, you need to have repeat EKG.

If needed doctor can advise you for 24 hour EKG or event monitor when you feel the increase rate, you can record it.

Pain in the heart area, can be from heart or from non cardiac cause.

Pain from esophagus, stomach, muscles, bone can be felt in that area and be mistaken as heart pain.

EKG, echocardiogram should be taken to exclude any heart issue.

Consult with your doctor for detail investigations to find out the exact cause.

Please ask if you need any clarification.

Best wishes.
Customer: replied 6 years ago.
Well. thank you for the info but I knew most of that. You have not answered my question re is a fast heart rate dangerous. My thyroid level has been checked and found to be OK. I'm trying to establish a possible cause that my doctor has not considered, so there is no point returning there yet. Since contacting you I found an article that suggests to me that low blood sugar might be the cause. Does that sound likely?
Low blood sugar can cause increased heart rate and palpitation.

The rate of 100 -120 is usually not dangerous but can be dangerous too depending on the type of rhythm or the focus of the rhythm.

It also depends on the hemodynamic effect of the rate.
Customer: replied 6 years ago.
This gives me something to present to my doctor, so thank you for that. Finally, are you able to guess at the meaning of the third heart sound, heard when listening with my stethoscope, which becomes very pronounced at speed. It is precisely mid-way between S1 and S2 so is (in my amateur opinion) possibly not a split S1 or S2. It is heard loudest at the PMI, using the diaphragm, and is sometimes accompanied by what seems to be a very early systolic blowing murmur which disappears on moving from the left lateral decubitus position to the supine position. It is louder on inspiration but is still present on expiration. I am asking you this as I find it difficult to confess to my doctor that I have been listening to my own heart sounds to try to find an answer that, so far, she has not provided.
How is your hemoglobin level?

Did you have echo or holter monitor of the heart?
Customer: replied 6 years ago.
I wore a holter monitor for 24 hours but as luck (bad luck?) would have it, nothing unusual happened in that period. I have no information on my hemoglobin level but I had a blood test which may have included that.
In that case, an event monitor can be used to detect any abnormal rate or rhythm.

Usually hemoglobin included in routine blood test, I feel it is normal.

During deep inspiration, S2 may be split due to the aortic valve closing earlier than the pulmonary valve.

This splitting of S2 disappears during expiration.

The third heart sound sometimes heard in children and young due to rushing of blood into the ventricle when AV valves open at the beginning of the diastolic phase.
Customer: replied 6 years ago.
I did record that I am 61 years old so information about S3 heard in children is simply not relevant. My extra heart sound is (I think) too removed from S2 to be a widely separated P2 and it is there during inspiration as well as expiration. The extra sound is precisely mid-way between S1 and S2 and is as loud as S1 (also S2 appears to be quite loud - the same volume as S1 when listening at the PMI in the LLD position - which in itself could be a point of concern as it is not the best place to auscultate S2). And you have not commented on what appears to be the early systolic murmur I mentioned in my last post. Sorry to keep coming back to you but I do need some plausible suggestions to present to my doctor (or another doctor).
I did not get any age information before.

Common causes of early systolic murmur is small ventricular septal defect, tricuspid regurgitation, aortic stenosis.

I feel event monitor would be a good option to record any abnormal event which you are feeling time to time.

If needed you can ask for a referral for a arrhythmologist.

Edited by Dr. Saha on 9/4/2010 at 6:20 AM EST
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Customer: replied 6 years ago.
Thank you. I now have enough to present to my doctor. By the way, age and sex is requested by the main site before a question is asked. Is this inormation not being forwarded to you?
You are always welcome to JA.

Age and sex usually come at the end of the question.

But the information was not in your question.

Please press the accept button if you are satisfied with my answer so that I can be compensated for my time & work.

Best of health.

Edited by Dr. Saha on 9/4/2010 at 9:09 AM EST