Holter Monitor Result

38-yo female.  I have been referred to a cardiologist, neurologist, and a sleep clinic after feeling weak, nearly fainting and having blackouts, all starting about a month ago.  Holter monitor (48 hour) results:

General:
192680 QRS complexes
504 Ventricular beats (<1%)
33 Supraventricular beats (<1%)
2% of total time classified as noise

Ventriculars (V,F,E,I)
504 Isolated
0 Couplets
0 Bigeminal cycles
0 Runs totaling 0 beats

Heart Rates
42 Minimum at 5:11
68 Average
150 Maximum at 8:05
8162 Beats in tachycardia, 4% total
54446 Beats in bradycardia, 28% total
1.54 Seconds Max RR at 16:04

Supraventriculars (S,J,A)
31 isolated
1 couplets
0 bigeminal cycles
0 runs totaling 0 beats

Interpretation
Underlying sinus rhythm with intermittent episodes of sinus bradycardia and sinus tacycardia with rates from 42 to 150 bpm.  Occasional isolated vpbs, no V. tachycardia, very rare isolated apbs with one a. couplet, no svt. No important pauses. No significant st shift. Symptoms noted on diary correlated with isolated vpbs.

History: Current bloodwork normal.  Significant head injury/whiplash 2 years ago.  CT scan and MRI of head showed no permanent damage, but no such tests done on neck. Gestiational diabetes with first child, 12 years ago.  Lots of heart disease in family history.

Questions: Any comments on the significance of the results? Could left vagus nerve irritation cause anything like this?  What about sleeping in the same bed with someone who has pretty bad untreated sleep apnea?  What should I ask the doctors, or be sure to tell them?

Thanks in advance.

[is_something_wrong]

I'm no doctor, but in my opinion your Holter is almost textbook normal.

It's normal to have heart rates in the 40s and sometimes down to 30s during deep sleep, and your tachycardia is probably due to exercise, running to the bus, or similar? My Low-Avg-High on holter was 38-75-186 and that was considered completely normal (a bit high average due to some anxiety).

You have some single PVCs. I would say clearly within normal limits. A few PACs is definitly within normal limits. Holter computers tends to interpret several PACs as PVCs when they are very close to the preceding beat. It's a chance your PAC/PVC number are closer to 50/50 then it appears here.

The PAC couplet is nothing to worry about. Sinus pauses are significant if they are longer than 2,7sec at daytime and >3 sec nocturnal. Your longes sinus pause was 1,54 sec.

No st shifts = no sign of coronary artery disease.

If your PVCs are clustered up (i.e you get 100 in 5 minutes) this can possible cause low blood pressure and vertigo. I think this have other causes, but I would ask my doctor if he think vertigo/fainting has a cardial cause.

Good luck:)

[willowsword]

Thanks for your response.  The time they listed for the highest heart rate, I wouldn't have been exercising, but that doesn't mean that it was for a long period.  The other tach beats could have been when I was running in transit.  I didn't do anything more strenuous than a jog the whole time.

That's the tough thing from just looking at overall results, you don't know if they were grouped or spread out.  A bloodpressure monitor might be more revealing, but when I suggested it today they said my bp is fine.  But so is my heart rate every time the doctor checks it in his office.  :)

[willowsword]

A second thyroid test has come back hypothyroid. One a month ago my thyroid test came back normal, and a previous one in November came back boderline.  Hopefully that will be it.

[is_something_wrong]

Hypothyreoidea will usually not cause palpitations (though it might), this is usually caused by hyperthyreoidea.

However, it can cause low blood pressure and low heart rates, and it can explain your dizziness or fainting. Your doctor can tell you more about this.

Good luck :)

[crystalhanzelka]

I do not see anything alarming as well.  

[Mom2four85]

the only thing I would ask about is how much your heart was in bradycardia - it doesn't say how much of this was during sleep; if wasn't mostly in sleep (most probably were) this may need to be addressed, but is probably nothing and you have a naturally low HR